bangladesh - louisiana state university 16.pdf · bangladesh contents introduction the last case of...

CHAPTER 16

BANGLADESH

Contents

INTRODUCTION

The last case of smallpox in Asia and thelast case of variola major, the more severeform of the disease, occurred in Bangladesh(Fig . 16.1) on 16 October 1975 . It might notseem surprising that Bangladesh was the lastAsian country to eliminate smallpox . Of allthe countries of the world, it was one of thepoorest and most densely populated . How-ever, Bangladesh (East Pakistan until Decem-ber 1971) had already succeeded once ininterrupting transmission 5 years earlier, inAugust 1970. The achievement had beenremarkable and unexpected, occurring just 8months after limited resources had beendiverted from an extensive mass vaccinationcampaign to a simple surveillance and con-tainment programme. Most observers be-lieved that other undetected foci would

807

become apparent during the subsequent dryseason, from October 1970 to the end ofMarch 1971, when more rapid transmissionoccurred . However, 6 months went by with-out further cases being found. Suddenly, inMarch 1971, a tragic and violent civil warbroke out, 10 million refugees fled to India,and health programmes and organized sur-veillance activities virtually ceased . However,up to the end of December 1971, no smallpoxpatients were admitted to the infectiousdisease hospitals, no cases were reported byhealth staff and none were detected amongthe continuing flood of refugees enteringIndia.

Many of the refugees who fled to Indiawere housed in special camps, hurriedly set upin areas near the border. They were supposedto have been vaccinated on arrival, but inseveral camps, including the largest, near

PageIntroduction 807Background 809Smallpox and its control before 1968 810The WHO-supported eradication programme begins, 1968 814Initiation of surveillance-containment and the interrup-

tion of transmission, 1970-1971 816The refugee camps and the reintroduction of smallpox,

December 1971-May 1972 820The programme is re-established, June 1972-September

1973 823Reorganization of the health services, October 1973 826An emergency plan for smallpox control, April 1974-

January 1975 829National mobilization for smallpox eradication, February

1975 835Special search programmes 840The final chapter 842The last outbreak 843Morbidity and mortality data 847Conclusions 847

808

NEPAL

ill

,or

%

.-

BANGLADESH

Dhaka .

INDIA KhulnaCalcutta .

Bhola

Bay of Bengal

CHINA

BHUTAN

Fig. 16 . I . Bangladesh and surrounding countries .

Calcutta, few were, in fact, vaccinated . Small-pox broke out in November 1971 and spreadrapidly. Because cases were incorrectly diag-nosed, nothing was done to contain theepidemic until late in January 1972 .

Meanwhile, on 16 December 1971, Bangla-desh became an independent state, and everyday thereafter thousands of refugees, many ofwhom were infected with smallpox, began toreturn home. This mass migration took placeat the beginning of the season of highesttransmission. The health service, devastatedby civil war, could not cope with the situa-tion ; epidemic smallpox swept through tem-porary refugee camps, cities and rural areas.

The eradication programme was reconsti-tuted and strengthened, but, despite far moreintensive efforts than had been made in 1970,transmission persisted year after year between1971 and 1975, as one disaster followedanother. At different times, famines, floods,civil disorder and the forcible displacement ofurban slum dwellers caused hundreds ofthousands of people to flee their homes . Thenational health services were reorganizedat a critical time, in 1973, seriously ham-pering field activities ; and national leadersperiodically redirected the smallpox era-

SMALLPOX AND ITS ERADICATION

INDIA

0

300 km

dication programme towards mass vaccina-tion campaigns.

In the spring of 1975, a greatly strength-ened although frustrated and demoralizedstaff made one more concerted effort to stoptransmission and ultimately succeeded inOctober 1975, when the last case occurred.

During its final year the eradication pro-gramme in Bangladesh utilized and furtherdeveloped methods that had been elaboratedover the preceding 8 years of the IntensifiedSmallpox Eradication Programme and em-ployed experienced personnel from manyother countries. The national programme isthus of special interest. However, if therefugees in the camps in 1971-amounting toperhaps 300 000 persons-had been vacci-nated, this chapter would have been verybrief ; 223 000 fewer cases of smallpox wouldhave occurred and more than 40 000 deathswould have been averted .

Of the national smallpox eradication pro-grammes, that in Bangladesh is one of thebetter documented ; much of the material forthis chapter is drawn from a book by Joarderet al . (1980), The Eradication of Smallpox fromBangladesh. The book also describes the eradi-

Fig . 16 .2 . Bangladesh : population density bysubdivision in 1967 .

Table 16 . I . Bangladesh : administrative units in 1972

a in 1983-1984, the structure was changed so that eachSubdivision was designated a District and thanas were renamedupazilas .

cation staffs experience in the practicalapplication of techniques for surveillance andassessment in other health programmes.

BACKGROUND

The richly fertile country of Bangladeshlies at the delta of three of Asia's great rivers-the Ganges, the Brahmaputra and theMeghna. More than nine-tenths of thecountry is less than 15 metres above sea level,and as much as one-third of the agriculturalland is flooded during the June-Septembermonsoon. In 1967, Bangladesh had a popula-tion of some 62 million, one of the fastestgrowing and with the highest density of anymajor country (428 persons per square kilo-metre). The central and southern parts of thecountry were the most densely settled (Fig .16 .2). Even in areas in which vaccinialimmunity was comparatively high, the num-ber of susceptible individuals per squarekilometre was greater than in most endemiccountries .

There was considerable population move-ment throughout the country . Nearly 95 % ofthe people lived in rural areas, but 30% werelandless and even those with some land oftheir own often sought part-time work else-where as tenant farmers or labourers . Atplanting and harvest times, hundreds ofthousands of people travelled up to 200kilometres in search of work . Although therewere only 3 cities in 1974 with populations ofmore than 300 000-Dhaka (1 .8 million),Chittagong (970 000) and Khulna(480 000)-all cities and towns had largeunenumerated transient populations enteringand leaving each day . A study in Dhaka in1976, for example, showed that more than110 000 persons passed daily through its main

16. BANGLADESH 809

Fig . 16 .3 . Bangladesh : divisions and districts as of1972 .

points of entry. However extensive the move-ment of people, village and family ties re-mained especially important in this tradi-tional Muslim society, so that those who fellill frequently travelled long distances to becared for in their home villages by theirfamilies . In this setting, the transmission ofsmallpox from urban to rural areas was rapidand widespread.

Undernutrition and malnutrition werecommon even when harvests were good . In1962-1964, it was estimated that the residentsof only 54% of rural households were ade-quately fed, and by 1975-1976 this propor-tion had decreased to 41% . Because of theprecarious nutritional situation, even a smalldecrease in food supplies had a disproportion-ately heavy impact, causing hundreds ofthousands of people to migrate from one areato another, many to the cities . At such times,smallpox spread with facility .

Travel by land was time-consuming anddifficult, making it hard to supervise theprogramme effectively and to transport sup-plies to smallpox eradication staff in the field .A network of 4000 kilometres of all-weatherroads radiated from Dhaka to district townsbut major ferry crossings were encounteredfrequently and roads were often damaged or

Administrative Number number Avareae

Averageunits

In next

(km2)

populationlarger unit

Division

4

-

36 000

17 618 000District

19

5

7 500

3 709 000Subdivision

57

3

2 500

1 236 000Thana

424

7

330 166 000Union

4 266

1 1

30 17 000Village

64 493

i S

2.5 1 000

810

washed out by monsoon rains . Hundreds ofthousands of river-boats provided transportfor many travellers ; although they were slow,they were inexpensive and permitted exten-sive population movement, especially duringthe monsoon season .

The various administrative units, to whichreference is made later, as well as their averagearea and population size, are enumerated inTable 16.1 . Division and district boundariesare shown in Fig. 16.3 .

Each village was composed of a number ofbaris. A bari usually corresponded to ahousehold, but it also referred to a compoundoccupied by an extended family and some-times included the houses of servants andother employees in the wealthier families .

In each district and subdivision, civilsurgeons were responsible for all curative andpreventive services except for the malariaeradication programme, which operated as anautonomous activity until late 1973 . One ortwo medical officers were usually assigned toeach than, the basic administrative unit, butpreventive measures were the responsibilityof a sanitary inspector, who supervised some5-10 government health assistants . Eachgovernment health assistant-a category ofstaff usually recruited locally-was in charge


Plate 16 .1 . River-boats provided transportation for many travellers in Bangladesh and, with the large crowds,smallpox spread rapidly and widely across the country .

of a union. Many of the government healthassistants had had no more than an elemen-tary-school education ; none were well paid oradequately supervised. Until late 1973, themalaria eradication programme, one of thebest of its kind in Asia, had an independentbut roughly parallel structure. Its staff,however, was of a generally better quality,received higher pay and was far more reliablysupervised.

SMALLPOX AND ITS CONTROLBEFORE 1968

As elsewhere in the Indian subcontinent,only the variola major variety of smallpox wasknown to have occurred, and this fertile,heavily populated delta area may well havebeen one of the earliest endemic areas in Asia .Until late in the 19th century, protection wasafforded primarily by variolation, performedby indigenous practitioners. Vaccination,with liquid vaccine produced in Calcutta, wasintroduced in 1860 in areas near Calcutta andin certain of the district towns of what is nowBangladesh. In 1874, the authorities decidedthat variolation should be abolished and theyencouraged the variolators to replace variola

80 -

1956

1958

1960

1962

1961 : national smallpoxeradication scheme

virus by vaccinia virus. By the turn of thecentury, as vaccination became more widelyavailable, variolation ceased altogether . In1947, the production of liquid vaccine be-gan in Dhaka, and up to 1961, vaccinationwas performed throughout the country bygovernment-paid vaccinators supervised byhealth inspectors in each than. The extent ofvaccinial immunity is unknown but withonly the thermolabile vaccine available inthis subtropical area, many vaccinations wereprobably unsuccessful .Smallpox was known in Bangladesh as

boshonto, the Bengali word for spring, theseason of highest incidence of the disease . Asin India, major epidemics were recordedevery 4-7 years. After 1947, the year in whichPakistan became independent, major epi-demics were recorded in 1951 and 1958 (Fig .16.4), the latter being so extensive thatassistance for its control was sought fromother countries. In all, 79 060 cases with58 891 deaths were reported that year, afigure which, because of poor reporting, wasundoubtedly one-tenth or less of the actualtotal. One of the groups providing assistancewas a team from the United States Communi-cable Disease Center (later, the Centers forDisease Control), Atlanta. This teamestimated that 60-70% of the people hadvaccination scars but could find no correla-tion between the level of vaccinial immunityand the intensity of the epidemic in different

16. BANGLADESH

Intensified SmallpoxEradication Programme

1964

1966

1968

1970

Aug. 1970 : last reportedcase in Pabna

1972 : reintroduction of _smallpox

Fig . 16 .4 . Bangladesh : number of reported cases of smallpox, by year, 1950-1977 .

1972

811

areas. The team members were impressed bythe size of the epidemic and the density of thepopulation and suggested that "the numberper square mile of unvaccinated personswould be a better index of the susceptibility. . . than the index that is ordinarily used, theproportion of the population that has beenvaccinated" (Usher, 1960) . They concludedthat the "feasibility [of global eradication]under presently existing circumstances isdependent on the likelihood of success incountries where eradication is likely to bemost difficult to accomplish and the obstaclesgreatest . One of these countries is Pakistan. . ." (Usher, 1960). As an outcome of theepidemic, it was decided to develop alaboratory in Dhaka capable of producingfreeze-dried vaccine, but substantial quan-tities of such vaccine did not becomeavailable until 1966 .

Resolution WHA12 .54, adopted by theTwelfth World Health Assembly in 1959,called on all countries to join in a massvaccination programme with the aim oferadicating smallpox . This initiative wasenthusiastically supported by the Pakistanigovernment and a campaign commenced inEast Pakistan in 1961. The intention was tovaccinate the entire population within two orthree years .During the 3-year period 1961-1963,

72 million vaccinations were reported to havebeen performed and, during the succeeding 3

812


years, 68 million more-in all, more thantwice the population of the country (Table16.2). From field observations in 1967 and1968, it was apparent that the reportednumber of vaccinations was greater than thenumber actually performed and, as was thecase elsewhere in Pakistan and in India, themost accessible persons, such as schoolchil-dren, were vaccinated repeatedly while otherswere not vaccinated at all . Nevertheless,vaccinial immunity in the population un-doubtedly reached higher levels than everbefore. Only 69 cases of smallpox werereported in 1964, and 316 in 1965 . In 1966,the number of cases again increased, reaching3207 that year and 6648 in 1967 .

During the summer of 1967, epidemi-ologists who had conducted studies of small-pox in West Pakistan (see Chapter 14)decided to undertake similar studies in ruralEast Pakistan. A combined team from thePakistan Medical Research Centre in Lahore,the Cholera Research Laboratory in Dhaka,and WHO studied the epidemiology ofsmallpox in an area in which cholera vaccinetrials were then in progress . These investiga-tions, along with those in West Pakistan,were the most comprehensive epidemiolog-ical studies conducted during the entireglobal eradication programme and provide aninteresting overview of the smallpox situa-tion at that time in one subdivision of thecountry (Thomas et al., 1971a,b) .

The area studied was Matlab Thana, Co-milla District, 65 kilometres from Dhaka ; it

Table 16 .2 . Bangladesh: population and number of reported vaccinations and number of reported cases ofsmallpox, 1961-1976a

a Population estimates from United Nations (1985) .

included 132 small rural villages (population,113 000) scattered over approximately 200square kilometres . Vaccinators had beenemployed in the district since 1930, travel-ling from village to village to vaccinatenewborn children and revaccinate others,using the rotary lancet and liquid vaccine .Comilla District had served as a pilotprogramme area for the 1961-1963 massvaccination campaign and, for this operation,additional vaccinators had been employed.Therefore, as the investigators noted, vacci-nial immunity among individuals over 5years of age may have been better than inother parts of East Pakistan .

In May 1967, experienced interviewers,employed in the cholera vaccine trials, visitedeach house throughout the area to assessvaccinial immunity ; in all, 103 539 personswere examined. In July, each house wasagain visited in an effort to identify, by meansof an interview, all cases which hadoccurred between 1 July 1966 and 30 June1967 .Of the people examined, 80 .8% had a

vaccination scar, the largest proportion of theunvaccinated being among children under 5years of age (Table 16 .3). This age groupshould have been vaccinated during the"maintenance vaccination" campaign, but, asis apparent, that programme was far fromsatisfactory .

Thirty different outbreaks, occurring in 27villages, with a total of 119 cases, wereidentified . Of these, only 5 outbreaks and 13

Year Population(millions)

Primaryvaccinations Revaccinations Number of

reported casesof smallpoxNumber

(thousands)% of

populationNumber

(thousands)% of

population

1961 52 .9 374 0 .7 22 070 41 .7 6601962 54 .2 3 509 6 .5 24 145 44 .5 6101963 55 .6 2 546 4.6 19 481 35 .1 3 7351964 56 .9 1 490 2 .6 18 104 31 .8 691965 58 .4 1 505 2 .6 18 245 31 .3 3161966 59 .9 2 041 3 .4 26 275 43 .8 3 2071967 61 .6 2 266 3 .7 26 475 43 .0 6 6481968 63 .2 2 626 4.2 30 201 47 .8 9 0391969 64 .9 1974 3 .0 29 636 45 .6 19251970 66 .7 1 602 2.4 16 991 25 .5 1 4731971 68 .5 432 0.6 5 835 8 .5 01972 70 .5 2 496 3 .5 34 215 48 .6 10 7541973 72 .5 3 660 5 .1 33 237 45 .9 32 7111974 74 .5 4445 6.0 10 669 14 .3 16 4851975 76 .6 5 773 7 .5 17 905 23 .4 13 7981976 78 .7 848 1 .1 4 355 5 .5 0

cases had been officially reported but, as inWest Pakistan, the reported outbreaks in-cluded 5 of the 6 largest, in which 54 caseshad occurred . In 7 outbreaks, special vacci-nation control campaigns had been con-ducted by government vaccinators but withlittle apparent effect .

The age distribution and case-fatality rates(Table 16 .4) were similar to those observedelsewhere in Pakistan and in India. Thirty-four (29 0 ' ) of the cases were in childrenunder 5 years of age, 55 (46%) in individualsaged 5-19 years and 30 (25%) in those aged20 years and over . Thirty-four of 111 persons(31%0) of known vaccination status hadpreviously been vaccinated, all except 6 ofthem being 10 years of age and older . Withdata available regarding the vaccinationstatus of the population as a whole, it waspossible to calculate vaccine-efficacy ratiosby age based on vaccination at some time inthe past (WHO/SE/69 .11, Thomas et al .) .The ratios showed 94-96% protection forthose aged up to 14 years ; 89% for those aged15-24 years ; and 74% for those aged 25 yearsand more. The ratios were remarkably high,although not so great as those found in SouthAmerica, in which only the mild variolaminor variety of smallpox was present .

The epidemiological pattern of spread wasof special interest . Thirteen of the 30outbreaks consisted of only a single case, andin 9 others the disease was not transmittedbeyond the initially infected bari. Moreover,24 of the outbreaks terminated after less than2 generations of spread . Despite the densityof population and a lower level of vaccinialimmunity, smallpox tended to spread lessrapidly and to remain more localized than inWest Pakistan . The sources of 22 outbreaks

Table 16 .3 . Matlab Thana study area, ComillaDistrict : vaccination scar survey, 1967,by age groupa

Age group

Number(years)

examinedWith vaccination scar

Number

a From Thomas et al . (197 1 a,b) .b Includes 68 persons of unknown age of whom 18 were without

a vaccination scar .

16. BANGLADESH 813

were identified. All but 1 of the sources wereoutside the study area and 15 of the 22originated in cities of 100 000 inhabitants ormore, in which only 5 % o of the population ofthe province resided . In this study popula-tion, continuing transmission of smallpoxfrom village to village had not occurred and,in fact, no cases whatever were detectedwhose onset took place between Septemberand December 1966 .

The investigators concluded that it waseven more important in East than in WestPakistan to eliminate smallpox from urbanareas, an objective which, if achieved, wouldprevent a high proportion of rural cases .Moreover, it appeared that most outbreaks inrural areas might be contained simply byvaccinating the inhabitants of the affectedand neighbouring baris rather than the popu-lation of the entire village . Noting the highvaccine-efficacy ratios, the investigators rec-ommended that a continuing programme ofmaintenance vaccination should concentrateon vaccinating those who had never beenpreviously vaccinated, especially childrenaged 5-14 years not attending school andlandless labourers working in urban areasidentified as the two groups most likely totransmit smallpox from place to place.

For a settled population and one which wasas well vaccinated as that of Matlab Thana, therecommendations were sound and in 1970the programme would substantiate theirvalidity. However, when mass migrations ofrefugees took place, as happened repeatedlyafter the country became independent, andwhen smallpox outbreaks occurred in areas inwhich vaccinial immunity was low, moreextensive containment measures were foundto be required .

Table 16.4. Matlab Thana study area, ComillaDistrict : number of reported cases ofdeaths from smallpox and case-fatalityrates, 1967, by age groupa

a From Thomas et al . (1971 a).

Age group Number of Number of Case-fatality(years) cases deaths rate (%)

<I 10 7 701-4 24 10 425-9 38 6 1610-19 17 3 1820 30 3 10

Total 119 29 24

< 1 3 356 207 6 .21-4 15 044 6 206 41 .35-9 19 995 16 045 80 .210-14 14 278 13 178 92 .3

15 50 798 48 009 94 .5

Total 103 539b 83 695 80 .8

814

THE WHO-SUPPORTEDERADICATION PROGRAMME

BEGINS, 1968

In July 1967, Dr Ehsan Shafa, the regionalsmallpox adviser from the WHO RegionalOffice for the Eastern Mediterranean, andArita held meetings with government offi-cials in Islamabad, the national capital, andDhaka, the capital of East Pakistan, anddeveloped a draft plan of operations . Thegovernment agreed to the plan in principleand submitted a letter to the WHO RegionalOffice requesting assistance. This letter per-mitted funds to be obligated and supplies tobe procured well before a more formalagreement was signed by WHO and thegovernment, inevitably a long process . (Theagreement was not, in fact, signed until 26April 1968 .)

The principal component of the plan was amass vaccination campaign, as in WestPakistan . It was thought that a well-orga-nized campaign and concurrent assessment ofthe results, coupled with the use of freeze-dried vaccine and bifurcated needles, wouldachieve a higher level of vaccinial immunitythan had previous campaigns . Provision wasmade for surveillance teams in areas in whichmass vaccination campaigns were in progress,but the concept of a national surveillanceprogramme did not take shape until 1969 .


Although the findings and recommendationsof the research team were available tonational and WHO staff by early 1968, theywere almost wholly ignored in the implemen-tation of the national programme .

The plan called for a special full-time staffcomprising a headquarters office with physi-cians and supporting staff, 2 medical officersin each district, a medical officer in eachsubdivision and vaccination teams totallingsome 1500 persons. The programme was tobegin in 6 of the 17 districts and was to becompleted in these districts during the firstyear of operation . Vaccination campaignswould subsequently be conducted in theremaining districts during the second andthird years. The vaccination teams wouldmove progressively from one union to thenext and assessment teams would check thecoverage . It was expected that sufficientfreeze-dried vaccine could be produced by theDhaka laboratory for both East and WestPakistan . For the first year, WHO providedthe following items : 10 motor vehicles, 130motor cycles, 5 boats and 1500 bicycles, inaddition to other supplies . Up to the end of1971, WHO support to the programmeranged between US$ 67 000 and US$ 201 000per annum (Table 16 .5) . It did not increasesignificantly until 1974 .

A WHO epidemiologist, Dr Karel Mark-vart, arrived in January 1968 to help with the

Plate 16.2 . A : Mohammad Ataur Rahman (b. 1925) as deputy director of the vaccine production laboratoryin Dhaka, Bangladesh, played an important role in its development and, later, as health adviser to the PlanningCommission, provided essential support for national mobilization for smallpox eradication in 1975 . B: KarelMarkvart (b. 1933) was a WHO adviser to the programme in Bangladesh from 1968 to 1971 .

organization of the national mass vaccinationcampaign. The problems in mobilizing andtraining so large a staff were staggering .Additional government funds were requiredto implement the programme (2 .5 millionrupees-i .e., US$ 250 000) but because theagreement was not signed by the governmentuntil April 1968 no funds were madeavailable before the fiscal year beginning1 April 1969. A full-time national counter-part-Dr A. M. Mustaqul Huq, an able anddedicated public health officer-was notassigned until July 1969 .

In 1968, the organization of health servicesin 12 of the 19 districts was chaotic . In the 12so-called "non-provincialized" districts, therewas a dual management structure . A districtcouncil appointed and paid the salary of adistrict health officer, who was responsiblefor preventive activities, while the provincialgovernment appointed and paid a civilsurgeon, who was responsible for bothcurative and preventive activities . At the nextlower level, the subdivision, health activitieswere under the direction of a subdivisionalmedical officer of health, appointed and paidby the provincial government . He wasrequired to supervise sanitary inspectors, whowere appointed and paid by district councils .In their turn, they were expected to supervisevaccinators, who were recruited and paid bythe provincial government. In addition,municipal staffs were independently directedby municipal committees and were notresponsible to provincial or subdivisional

16. BANGLADESH

815

Table 16.5 . Bangladesh : support provided to the smallpox eradication programme, 1967-1977, by source(U$ a

NOTE: WHO records for 1967-1971 reflect support to both East and West Pakistan . Approximately half (the figures shown in parenthesesIn this table) was provided to East Pakistan . The principal contributors to the WHO Voluntary Fund for Health Promotion were Canada,Denmark, Norway, Sweden and the United Kingdom . The United Nations Relief Operation, Dacca (UNROD), provided US$415 000 ;UNICEF provided US$20 000.

a From Joarder et al . (1980) and WHO financial records.b Estimated .c Not including the cost of 45.3 million doses of vaccine.d . . = data not recorded .

government health staff. Appointments bydistrict councils and municipal committeeswere as often decided by political consider-ations as by qualifications ; discipline inperformance and coordination were chronicproblems which plagued the programmethroughout its course. In the remaining 7districts, the health services had been "pro-vincialized" and there, with all health staffappointed and paid by the provincial govern-ment, the health structure operated moreeffectively .

At the end of 1968, the Dhaka municipalcommittee was persuaded to provide fundsand staff to undertake a mass vaccinationcampaign, in part as a pilot study, but also inrecognition of the role of this urban area asthe country's principal focus of the spread ofsmallpox. The campaign was reasonablysuccessful as measured by a vaccination scarsurvey ; by the end of the campaign, morethan 90% of the population had vaccinationscars (Table 16 .6). After May 1969, nosmallpox cases were detected in Dhaka formore than 2 years.

Table 16.6. Dhaka Municipality : vaccination scarsurvey, 1969, by age group

Year Governmentb WHO regularbudget

WHOVoluntary Fund

for Health PromotioncUnIted Nations

Relief Operation/UNICEF Total

1967 d (201 080) 201 0801968 d (73 847) 73 8471969 d (113 797) 113 7971970 d (129 363) 129 3631971 d (67 216) - - 67 2161972 562 500 106 041 12 431 435 000 1 115 9721973 1 625 000 207 862 76 529 1 909 3911974 2 137 000 227 654 199 757 2 564 41 11975 1 582 000 126 049 3 074 788 4 782 8371976 1 000 000 119 280 1 719 425 2 838 7051977 1 000 000 128 300 998 530 2 126 830

Age group(years) Number examined % with vaccination scar

0-4 1 387 76 .85-14 1951 93 .2

15 1 695 98 .0

Total 5 033 90 .4

816

Table 16 .7 . Bangladesh: vaccine production at the

Dhaka laboratory and vaccine do-

nations, 1972-1977

Year

Number of vials

Produced by the

Donated byDhaka laboratory

other countries

Vaccine production, meanwhile, proved tobe an unexpected problem. The quantity ofvaccine produced was less than had beenexpected and barely sufficient to supply EastPakistan . Between 1966 and 1971, the labora-tory produced an estimated total of 4 millionvials of freeze-dried vaccine . Vaccine qualitywas said by the laboratory director to besatisfactory, but when samples from 7 batcheswere tested in the WHO smallpox vaccinereference centre in Bilthoven, Netherlands,in late 1968, only 3 met the acceptedstandards. Thereafter, the director permittedno one to have access to the laboratory'srecords. He asserted that the vaccine wassatisfactory, but examination of a further 10batches in 1969 showed that only 3 were upto standard. Because of production problems,a consultant was recruited by WHO to workwith the laboratory staff and after this thequality of the vaccine improved and therecords again became accessible . However,some difficulties in producing a stable vac-cine persisted throughout the programme.

Vaccine production data by year areavailable only for the period 1972-1977 . Thequantity produced was gradually increasedafter the provision by WHO of additionalequipment and supplies, so that by 1973 morethan 10 000 vials a week were being manufac-tured. Nevertheless, up to 1975, additionalvaccine was required and this shortfall wasmet by a number of donors through contribu-tions to the WHO vaccine reserve stocks(Table 16.7).

In April 1969, the government-fundedposts for the vaccination campaign werefinally established, but recruitment proved tobe such a cumbersome procedure that notuntil January 1970 did sufficient staff becomeavailable to permit mass campaigns to beginin 15 of the 21 subdivisions in 7 of thecountry's 19 districts . In the execution of theprogramme and in the reporting of cases, it


was agreed that the divisional and districthealth authorities would be bypassed, thusstreamlining the structure so that only 4levels would be involved in administrativedirection and case reporting-headquarters,subdivisions, thanas and unions.The vaccination campaign made slow

progress, however. By November 1970, theteams had vaccinated only 4.5 million per-sons, little more than 6 % of the population ofthe country (Sommer et al., 1973). Mean-while, local vaccinators reported that theyhad vaccinated 32.8 million people in 1968and 31 .6 million in 1969, although thesefigures were considered to be inflated . In1970, vaccination scar surveys in the 7districts in which mass vaccination had beenperformed showed 4 in which the proportionof the population with vaccination scarsranged from 64.9% to 72.1 %, substantiallylower than the 80 .9% found by the researchteam in Comilla . In the other 3 districts, theproportions with vaccination scars were,respectively, 75 .6%, 77.5% and 86.2% .

The number of reported cases reached apeak of 9039 in 1968, the highest total in adecade, but declined to 1925 in 1969 . What, ifanything, this implied was unknown sincelittle had been done to improve the reportingsystem .

INITIATION OF SURVEILLANCE-CONTAINMENT AND THE

INTERRUPTION OF TRANSMISSION,1970-1971

It had been agreed that in addition to thevaccination staff, there should be a surveil-lance team for each subdivision in which themass vaccination campaign was conducted .As the plan of operations stated, the teamwould (1) control any reported attack ofsmallpox, and (2) if no cases were reported,vaccinate any person who had been missedafter the operational (vaccinator) group hadleft the area. This first official recognitionthat there should be surveillance teams wasencouraging but, conceptually, still far re-moved from the objective of establishingteams solely responsible for developing thereporting system, detecting cases and con-taining outbreaks throughout the country .

In November 1969, a WHO intercountryseminar on smallpox was convened in Dhakawhich illustrated, on the basis of reports fromwestern Africa and Brazil, what could be

1972 343 380 26 0001973 807 000 190 0001974 963 500 453 0001975 730 152 1136 0001976 458 750 01977 703 600 0

achieved with more effective case detectionand outbreak containment. East Pakistan hadreported only 4 cases in September and 1case in October 1969 . With so few reportedcases, it was decided that from January1970 an effort would be made to investigateevery reported case . A surveillance section,headed by a medical officer, was establishedand 1 central and 4 divisional surveillanceteams were recruited to improve reportingand to investigate outbreaks throughoutthe country . Because government travelallowances were too meagre to cover even themost modest board and lodging, WHOagreed to provide the teams and other seniorsupervisors with a supplementary per diemallowance to permit them to travel in thefield . The leaders of the 4 divisional teams, DrM. A. Sabour, Dr M . Yusuf, Dr M. Shahabud-din and Dr M. A. Khan, proved to beexceptionally able and dedicated and served inthis capacity throughout the entire pro-gramme. In January 1970, the first monthlysurveillance report was issued, and this seriescontinued to appear, with interruptions dueto civil war, throughout the programme .

Because the time of Dr Markvart and DrHuq was fully taken with the complexlogistics of the mass campaign, Arita wasassigned from WHO Headquarters for themonths of February and March to help todevelop the surveillance programme . Incollaboration with the newly constitutedsurveillance teams, he investigated reportedoutbreaks in various parts of the country. Tothe surprise of all concerned, the teamsdiscovered that cases being reported from thecentral and southern parts of the countrywere not smallpox but chickenpox and otherskin diseases. On the other hand, in anorthern district, the investigation of anewspaper report of 6 cases led to thedetection of 93 cases of smallpox . By the endof March, it appeared that smallpox waslocalized in only 5 northern districts of thecountry. Arita suggested that the vaccinationcampaign should be temporarily suspended infavour of an emergency surveillance-con-tainment campaign whose objective would beto interrupt transmission before the monsoonrains. With the agreement of a newlyappointed and highly competent Minister ofHealth, Colonel M . M. Haque, and after thesurveillance teams had been specially trained,such a campaign began ; it was one of themost dramatically successful of the entireglobal eradication programme .

16. BANGLADESH 817

To facilitate surveillance, the reportingsystem was changed. The detection andidentification of cases had depended on atraditional routine in which a local govern-ment employee, the chowkidar (who servedalso as the village watchman), was responsiblefor the weekly reporting of births, deaths andnotifiable diseases to the than headquarters.The chowkidars were frequently illiterate,poorly paid and ineffectual . Reports receivedat the thana were forwarded by mail to thesubdivision, and then to the statistical sectionof the Ministry of Health . Reports weresubmitted sporadically, often after delays ofseveral weeks, through a mail system that wasanything but reliable .

Beginning in April 1970, all healthworkers and the malaria eradication pro-gramme staff were asked to report eachsuspected case of smallpox they encounteredto the than sanitary inspector . The better-paid, better-supervised and generally moreresponsible malaria eradication workers visit-ed all houses throughout the country onceevery 2 weeks, searching for persons withfever who might have malaria and confirm-ing this by the examination of blood smears .For them to report suspected cases ofsmallpox entailed little additional work andno disruption of activity . Thana sanitaryinspectors were instructed to forward weeklyreports of all cases in their than to thesubdivisional medical officers . They in turnwere to report cases by telegram rather thanby mail to the Dhaka smallpox eradicationprogramme headquarters . When outbreakswere detected, the subdivisional medicalofficers as well as the thana health inspectorswere instructed to investigate and containthem. This system brought health workersinto the reporting system and streamlinedreporting by introducing telegraphic notifi-cation directly from the subdivision to thesmallpox eradication headquarters, thus by-passing the largely uninterested bureaucracyof the statistical section of the Ministry ofHealth .

The investigation of outbreaks generallyconfirmed the findings of the Comilla study :that most outbreaks originated in cities ; thatthe spread of smallpox from village to villagewas surprisingly infrequent ; and that out-breaks could be readily contained by vacci-nating the inhabitants of an infected bari andthose of a few baris surrounding it . In thenorthern part of the country, in which healthservices were less adequate and vaccinial

818

2400

2200

2000

1800x•

1600ro1 14000N•

1200V

•

1000

0800

600

400

200

0

Fig . 16 .5 . Bangladesh : typical seasonal variation insmallpox incidence, as shown by the number of re-ported cases in 1968 .

immunity was lower, village-to-villagespread was documented in 3 thanas in which13 outbreaks and 149 cases had occurred .Even here, however, the spread of smallpoxwas slow and although 3-7 months hadelapsed between the introduction of smallpoxand its detection, there were comparativelyfew cases in each generation of transmissionand the outbreaks were readily contained(Wkly epidem . rec ., 1970b). Between Januaryand March 1970, 1024 cases were detectedand reported but many of these representedcases which had occurred some monthspreviously. Few active cases were discovered .

In the entire country, only 263 cases weredetected in April and only 116 in May .Moreover, the cases were localized : 4 out of19 districts accounted for all but 59 cases . InJune, the 5 surveillance teams were assignedto work intensively in the remaining infectedareas and 10 surveillance teams previouslyworking with the vaccination teams were alsosent to these areas to contain outbreaks .Thirty-eight cases were discovered in June,23 cases in July, and 9 cases in August . InAugust, the teams detected and contained thelast known outbreak-in Pabna District .

J F M A M J J A S O N D

1968


Effective surveillance continued for another6 months but no further cases could be found .

In March 1971 civil war broke out, anduntil December 1971 the country was totallydisrupted. During this period, it is estimatedthat between 1 and 3 million civilians died,10 million refugees fled to India and anestimated 16.6 million people left their homesfor other parts of the country (Chen & Rohde,1973). Bridges were blown up, 1 .5 millionhouses were destroyed, and severe famineoccurred (Greenough & Cash, 1973).

Such evidence as is available substantiatesthe belief that, until 16 December 1971,when Bangladesh became independent, en-demic smallpox was absent from thecountry-a smallpox-free interval of 16 months . Duringthe period of civil war, no cases were found inany of the major cities, the usual sites ofendemic transmission . The divisional surveil-lance teams were proud of their achievementsand continued to travel widely throughoutthe country-albeit at considerable riskseeking information about possible cases butfinding none . The refugees who streamedceaselessly across the border throughout thisperiod were reasonably thoroughly screenedby Indian civilian and military health staff inan effort to detect cases of smallpox, but nonewas discovered. Moreover, when smallpoxwas reintroduced into Bangladesh, investiga-tion revealed that the primary source of eachoutbreak was a refugee who had contractedthe disease in 1 of 4 infected refugee camps inIndia or on the way home . During April 1972,almost all cases occurred among returningrefugees and their immediate contacts (Som-mer et al., 1973).

The comparative ease and rapidity withwhich smallpox transmission was interruptedin Bangladesh in the summer of 1970 was instark contrast to the staggering difficultieswhich were to mark the 4 years followingits reintroduction . In retrospect, the timing ofthe 1970 spring surveillance-containmentcampaign had been ideal, from the standpointboth of the season and of the longer-termperiodicity of smallpox. It had begun in thelate spring, when rates of transmission cus-tomarily declined and many outbreaks ter-minated spontaneously (Fig. 16 .5) . With re-gard to the longer-term periodicity, smallpoxincidence had peaked in 1968, with 9039cases, and in 1969 the annual reported inci-dence had declined sharply to 1925 cases . In1970, it is probable that no more than 150-200 cases would have been reported had not

16. BANGLADESH 819

Plate 16 .3 . Bangladeshis, infected with smallpox while living as refugees in India, returned to their newlyindependent country, only recently freed of smallpox, from December 1971 . Travelling in crowded trucksand trains, many lived in resettlement camps until their houses could be rebuilt . Smallpox spread widely andrapidly through the camps and across the country .

820


the special programme improved the com-pleteness of notification . Even so, only 1473cases were recorded . Moreover, at this time,neither flood, drought nor civil disorderresulted in famine and the extensive refugeemovements which were to mark succeedingyears. In some ways, the success of the 1970campaign had a negative effect by engender-ing an unwarranted degree of optimism thatsuch a favourable outcome could be achievedas readily and as rapidly again in Bangladeshas well as in other parts of the subcontinent .

THE REFUGEE CAMPS AND THEREINTRODUCTION OF SMALLPOX,

DECEMBER 1971-MAY 1972

Of the estimated 10 million persons wholeft the country, most were housed in crowd-ed camps. The largest, near Calcutta, was theSalt Lake Camp which sheltered an estimated200 000-300 000 refugees . Government pri-ority was given to supplying food, shelter andsanitary facilities. As noted in one report(Rohde & Gardner, 1973)

"The provision of relief to 10 million refugees. . . represented a monumental humanitarianachievement . That mass starvation and gallopingepidemics did not consume a greater portion ofthe refugee population is a tribute to the leader-ship, dedication and energy of the Indian Govern-ment . . .

"In contrast to the efficient conduct of the over-all relief effort, authority over health programswas not invested in any one group or person . . . Asa result, health policies and programs often lackedfocus, direction, and coordination."

The provision of smallpox vaccination wasone of these policies.

The Indian Ministry of Health had in-structed state governments to ensure that allrefugees were vaccinated against smallpox . Insome camps, vaccinations were given bygovernment staff and/or the personnel ofvoluntary relief agencies, and the conscien-tious performance of this task was confirmedby visiting Indian and WHO staff. However,state officials did not permit national healthpersonnel or WHO staff to visit the camps inWest Bengal so confirmation there was notpossible . Medical care in the Salt Lake Campwas under the supervision of a voluntaryrelief agency ; at that camp, as it was learnedlater, vaccination was ignored . It is likely thatcases of smallpox began to occur in Novem-ber, the source of infection being villages in

Plate 16 .4 . Left to right: D.J .M. Tarantola, WHOsmallpox eradication adviser in Bangladesh, 1974-1977; M . Sathianathan, a medical officer in Bangladesh,who had previously served as the WHO adviser forsmallpox eradication in Nepal ; A .K . Joarder, AssistantDirector of Health Services of Bangladesh and di-rector of the national smallpox eradication pro-gramme, 1972-1977 .

West Bengal. The cases were recorded aschickenpox by the health staff.

The epidemic was discovered by chance .On 19 January 1972, an American epidemi-ologist thought he could identify cases ofsmallpox in a television film of the camptransmitted to the USA. He telephoned theCommunicable Disease Center, which tele-phoned WHO Headquarters. WHO telexedthe government of India, which in turncontacted the West Bengal Ministry ofHealth. Although the state Director of HealthServices categorically denied there were cases,one of the national staff flew to Calcutta andimmediately found numerous patients. Theisolation of cases and vaccination began on23 January, but by then it was too late . On16 December 1971, Bangladesh had becomean independent country and refugees beganreturning home forthwith . By mid-January,an estimated 50 000 had left the Salt LakeCamp. Infectious cases, patients in the incuba-tion period and unvaccinated contacts wereall loaded together on trucks for the trip tothe border. It was the season when thetransmission of smallpox was most rapid andwith 26 million displaced persons movingfrom place to place, herded together intemporary camps and crowding the bustees(city slums), smallpox spread rapidly .

Under the best of circumstances the prob-lem would have been difficult to cope withbut at this time the health services were

130-

120-

110-

100-

, go-0-2-ME

80-

70`0

-vN

50 -

40 -

30 -

20 -

10-

1

,

Area IArea 2

_-_Area 3

I

N

1 1 1 ~1S 1 1 1, 1 1,,I

5

7

9

II

13 15

17 19 21 23Week number, 1972

Fig . 16 .6 . Khulna Municipality : number of reportedcases of smallpox in 1972 by week of onset in 3 areasof the city . Arrows indicate the week surveillance-containment activities started in each area .

seriously disrupted. So many motor vehicleshad been damaged or stolen that less than halfremained in working order, and only one-third of the number of bicycles required wereavailable. Boats had been damaged or sunkand because of the destruction of roads,bridges and ferries, travel from place to placewas difficult and time-consuming .

Arita, then on duty travel in India, flewimmediately to Dhaka, and working with DrM. Huq, the Director of Health Services,endeavoured to control the outbreaks . ByMarch 1972, the smallpox eradication head-quarters had been re-established under DrA. K. Joarder, Assistant Director of HealthServices ; divisional surveillance teams hadbeen reconstituted and were endeavouring todetect and contain outbreaks as best theycould. Smallpox continued to spread, how-ever, and 4 WHO epidemiologists were hur-riedly dispatched . Among them were DrStanley Foster, who had previously served asthe chief smallpox adviser in Nigeria, and DrNilton Arnt, one of the principal epi-demiologists who had worked in the eradi-

16. BANGLADESH

160-

140-

0̀80

Uvv 60

0ru 40

20

0 ,

1

,

Control activities

Il

821

?,11

1,1,113

5

7

9

II

13 15 17 19 21 23Week number, 1972

Fig . 16 .7. Kalishpur Bihari camp : number of reportedcases of smallpox in 1972 by week of onset .

cation campaign in Brazil . Some 3800 tem-porary vaccinators were hired to performvaccinations, primarily in the large tempor-ary refugee camps and surrounding districts .At first the epidemic was largely confined to 3south-western districts-Barisal, Faridpurand Khulna. Active search, however, revealedthe presence of smallpox in 27 of the country's57 subdivisions, although most had only a fewcases. The refugees were mainly Hindus andinitially the outbreaks afflicted Hindu areasand villages, but within a few generations ofdisease transmission, other groups were infec-ted as well. In March, epidemic smallpox wasdetected in Khulna Municipality, the thirdlargest city in Bangladesh . The control ofsmallpox in urban areas was recognized to bevital, and here a vigorous and remarkablysuccessful programme was begun on 28 April(Sommer, 1974 ; Sommer & Foster, 1974) .Eight 4-man surveillance teams were orga-nized and trained to identify infected casesthrough interviewing patients at the Infec-tious Disease Hospital and by visits to thebazaars. When a case was found in the city, allpersons in the household and compound werevaccinated and house-to-house searches wereconducted throughout the village or bustee .The area was revisited after 2 or 3 days andagain 3 weeks later to vaccinate individualswho had been missed during the first visit andto be certain that transmission had stopped .Containment measures were necessarily limit-ed in scope because of the paucity of staff andthe extent of the epidemic. In fact, it was

822

Fig . 16 .8 . Bangladesh : infected districts and numberof reported cases of smallpox as of 30 June 1972 .

necessary to divide the city into 3 seg-ments and to deal with each in turn. Although1073 cases were detected, smallpox was effec-tively contained within a matter of 4-6 weeksin each of the areas (Fig . 16 .6). Meanwhile, thedisease had broken out in a city refugee camphousing 30 000 persons. It was decided tovaccinate everyone in the camp by the simpleexpedient of making vaccination a prerequi-site for the receipt of relief supplies . Alto-gether 233 cases were detected ; however, theoutbreak was as successfully dealt with as theone in Khulna Municipality (Fig . 16 .7). Tohave achieved so much so quickly, with so fewhealth personnel, at a time of considerablecivil turmoil was a remarkable accomplish-ment and encouraged staff in the belief that

Table 16 .8. Bangladesh: transport provided to the smallpox eradication programme, 1967-1975

a Supplied by the United Nations Relief Operation, Dacca .


the flood of importations might yet besuccessfully contained .

However, smallpox was spreading rapidlythrough rural as well as urban areas, whereverreturning refugees settled. A survey of onerural than in May revealed 2298 cases among250 000 inhabitants-approximately 1 caseper 100 population . Meanwhile the diseasecontinued to spread through refugee resettle-ment camps, some of which housed Bangla-deshis of Bihari origin . From these camps, itspread to adjoining thanas. Small outbreaksdeveloped in Dhaka and Chittagong but thesewere controlled. Intensive studies of a numberof the outbreaks in which cases and deathswere thoroughly investigated revealed case-fatality rates of up to 28%, higher than thosefound elsewhere in the subcontinent andundoubtedly reflecting the extensive malnu-trition then prevailing .

By the end of June 1972, 6144 cases hadbeen reported in Bangladesh, of which 5834(95%) were from only 4 districts (Fig . 16.8) .Although reporting was recognized to beincomplete, it sufficed to indicate that largeparts of the country had few or no cases . Witha concerted effort such as had been made inKhulna and conducted throughout the mon-soon period of diminished transmission, thestaff hoped that the epidemic spread could becontained. Special assistance was given to theprogramme by the United Nations ReliefOperation, Dacca, in the form of motorvehicles, boats, outboard engines and bicycles .WHO provided motor cycles and additionalbicycles to facilitate the effort (Table 16 .8) .However, much of the transport served onlyto replace that which was worn out or hadbeen destroyed during the civil war .

Of the 4 WHO epidemiologists who hadassisted during the spring emergency, DrArnt and Dr Foster continued on permanentassignment in what proved to be one of themost arduous and taxing endeavours of theglobal eradication programme. They weresoon joined by 3 other staff, who remainedwith the programme essentially full time

1967-1971 1972-1973 1974 1975 Total

Motor vehicles 49 34a 0 35 118Motor cycles 183 110 50 165 508Boats 25 10a 0 8 43Outboard engines 28 Ila 20 31 90Bicycles 1 500 750a 2 370a 300 4 920

Plate 16 .5. Harkishan D. Mehta (b . 1934), a WHOepidemiologist with the Bangladesh programme,1974-1978, on the left, with Stanley O . Foster(b . 1933), a United States epidemiologist who hadpreviously served as senior adviser to the smallpoxeradication programme in Nigeria, 1966-1972, thenserved in Bangladesh as a WHO adviser for smallpoxeradication, 1972-1977 .

until transmission had been interrupted : DrNicholas Ward, who had previously beenemployed as a District Medical Officer inBotswana ; Dr Stanley Music, a Bengali-speaking epidemiologist who had previouslybeen stationed in Dhaka on assignment fromthe Communicable Disease Center ; and DrDaniel Tarantola, a physician who had beenworking at a hospital in northern Bangladeshwith a French voluntary organization .

THE PROGRAMME ISRE-ESTABLISHED, JUNE 1972-

SEPTEMBER 1973

The reporting system, which requiredweekly telegraphic reports from each of the57 subdivisions, was reinstituted in March1972 (Foster et al., 1980) . Reports to thesubdivisions were provided through thansanitary inspectors by government healthassistants, each of whom worked in a union,the health assistant/population ratio beingapproximately 1 to 15 000 . During the sum-mer, 4-man surveillance teams, headed by asanitary inspector, worked in each infectedsubdivision ; in each infected thana, vacci-nators were grouped into 3-man teams for

16. BANGLADESH

823

active search and containment . Particularemphasis was placed on the search in weeklymarkets by health workers using megaphones .This approach was later shown to detectapproximately 80% of all outbreaks withinan area of 65 square kilometres.

A mass vaccination campaign in the 4 mostheavily infected districts had begun in thespring, but was stopped when it becameapparent that it would accomplish little morethan the 1970 campaign. As Dr Huq and hiscolleagues stated in a report dated October1972 : "It is now clear that eradicationthrough mass vaccination is not feasible . . .The orthodox principle of blind, systematicvaccination has already been given up ."

Between June and October 1972, 400-800cases were detected monthly, a substantialnumber for that season of the year. However,up to the end of October, outbreaks had beendocumented in only 88 of the 409 thanas in thecountry, and by then only 36 were stillinfected . By the end of 1972, 10 754 cases hadbeen reported, approximately one-tenth ofthe number which had actually occurred, as asurvey for facial pockmarks carried out 4 yearslater was to show (Hughes et al., 1980 ; Fig.16 .9 ; Table 16 .9) . The system for detectingand reporting cases, although well designed,lacked adequate supervision .

After the monsoon, with the season of hightransmission approaching, it was decided toconcentrate resources in the subdivisions ofthe 4 most heavily infected districts . A 10-man team, headed by an assistant healthinspector, was assigned to each of the infectedthanas to search for cases and to contain anyoutbreaks that were found . A national sur-veillance team with 5 assessment staff super-vised these efforts and made repeated visits tothe sites of outbreaks to ensure that they hadbeen contained . Four surveillance teams,working under the supervision of the nat-ional eradication headquarters, travelledthroughout the areas which had reported onlya few imported cases to strengthen surveil-lance and to contain outbreaks.

The strategy was based on the assumptionthat smallpox would tend to remain localizedin the areas already identified as infected . Akey factor in the strategy was the control ofsmallpox in Dhaka, the capital and largest cityin the country, and the potential focus ofspread of smallpox into the largely smallpox-free areas of central and eastern Bangladesh .In April and May 1972,26 cases had occurredamong refugees in Dhaka but the outbreaks

824

Table 16 .9 . Bangladesh : number of reported casesof smallpox as a percentage of theestimated number of cases (surveillanceefficiency), 1972-1975a

a From Hughes et al . (1980) .

100 -

90

80

C)70

0

X 60-0a_m 50

0 40

vA 30-U

20-

10-

Unreported

Reported

1972

1973

1974

1975

1976

Fig . 16 .9 . Bangladesh: estimated total number ofsmallpox cases that occurred compared with thenumber of cases reported, 1972-1976 .

Table 16 .10. Dhaka Municipality: number of re-ported cases of and deaths fromsmallpox, by month, 1972-1973a

a From Joarder et al . (1980).b Including deaths related to cases reported in previous months .


were contained. Only a single case wasrecorded in July and another in August, butearly in October scattered outbreaks began tooccur in densely populated urban slum areasand resettlement camps, in which the night-time population densities were estimated tobe as high as 195 000 per square kilometre, or1 person to every 5 square metres. Twenty-nine cases were detected in October, 80 inNovember and 216 in December (Table16.10). The containment of outbreaks in thedensely congested areas seemed all but impos-sible short of an area-wide mass vaccinationcampaign .

In January 1973, Dr Ward assumed respon-sibility for the development of a specialprogramme in Dhaka to control smallpoxmore rapidly . A municipal headquarters wasestablished and 18 mobile surveillance unitswere formed .

• The Infectious Disease Hospital and themajor graveyards of the city were visited dailyto collect information on smallpox cases anddeaths .

Table 16 .11 . Bangladesh : number of reported casesof smallpox, by division and by month,1972-1973

Month Chittagong Dhaka Khulna Rajshahi Total

1972 :January 0 0 0 0 0February 0 59 165 248 472March 1 218 548 59 826April I S 547 437 20 1 019May 0 382 2 574 343 3 299June 1 73 451 3 528July 3 139 544 64 750August 13 237 400 27 677September 3 189 189 58 439October 9 81 308 10 408November 33 508 504 272 1 317December 92 234 546 147 1 019

Total 170 2 667 6 666 1 251 10 754

1973 :January 374 1484 161 1 450 3 919February 534 2 521 1838 389 5 282March 489 2 012 1926 852 5 279April 528 1905 1777 1 543 5 723May 372 1027 1068 1 710 4177June 247 672 910 954 2 783July 51 157 214 187 609August 101 425 464 330 1 320September 19 279 255 110 663October 106 259 170 III 646November 12 496 237 198 943December 62 637 234 404 1 337

Total 2 895 11 874 10 704 7 238 32 71 1

1972 1973

MonthNumber

casesof Number

deathsof Number

casesof Number of

deaths

January 0 0 633 380February 0 0 1550 991March 0 0 2 379 1409April 8 0 253 608bMay 18 3 72 115June 0 0 14 49July I 0 2 7August I 0 3 0September 0 0 0 0October 29 9 I 1November 80 24 0 0December 216 84 0 0

Total 353 120 4 907 3 560

YearNumber

reportedof

casesEstimated number

of casesSurveillance

efficiency (%)

1972 10 754 91 415 11 .81973 32 711 81 906 39.91974 16 485 33 390 49.41975 13 798 16 628 83.0

Total 73 748 223 339 33 .0

• Fixed check-points were established attransport terminals to collect informationand to vaccinate passengers .• Vaccination of the inhabitants of slumareas and refugee centres was carried out atnight as well as during the day .

During 1973, 1 747 000 vaccinations wereperformed in Dhaka City alone, but theepidemic did not begin to abate until April .Although only 4907 cases were detected, itwas apparent from the large number of deathsattributable to smallpox that there were manymore cases than this-an estimated 14 000 ormore.

Meanwhile, during the spring of 1973, 26surveillance teams worked throughout thecountry ; 5 of these were national teams eachwith responsibility for a region, 9 weredistrict teams, 4 were municipal teams and 7were assigned to the heavily infected sub-divisions. Each team moved from than tothan searching for cases in major markets,schools and selected villages. When an out-break was discovered, local health staff were

6000-

5000-

0

3000 -u

d

1000-

I

16. BANGLADESH

825

mobilized to vaccinate the residents of the 30houses nearest to those with cases.

The programme staff worked frantically tocontain the outbreaks but, with Dhaka heav-ily infected, smallpox quickly spread acrossBangladesh. The number of reported casesincreased from only 1019 in December 1972(Fig. 16.10) to 3919 in January 1973 and to5282 in February ; in February, cases werereported from every district in the country(Table 16.11) .

The epidemic reached its peak in April andonce again began to subside with the onset ofthe monsoon. The number of reported caseswas substantially greater than during thepreceding year, but since the number ofsurveillance teams had increased and notifica-tion was more complete, it was hoped thatduring the monsoon season transmissioncould be brought under control . To facilitatethis, containment procedures were changed,since it was found that outbreaks werepersisting because of failure to vaccinatehousehold contacts who were absent duringthe day. Accordingly, each team was required

1

M M J S N J M M J S N J M M J S N J M M J S N

1972

I

1973

~

1974

1

1975L Refugees

Integration of J

Floods)return

health servicesEmergency plan

National mobilization

Fig . 16 .10 . Bangladesh : number of reported cases of smallpox, by month, January 1972-December 1975 .

8 2 6


Table 16 .12 . Bangladesh: number of infected villages, by district and by month, 1974-1975

a Estimates calculated for 1977 as given by Joarder et al . (1980) .

to carry out house-to-house vaccination ineach infected village at night or in the earlymorning.

REORGANIZATION OF THEHEALTH SERVICES, OCTOBER 1973

In October 1973, only 646 cases werenotified. Reports were being receivedpromptly from 95% of the subdivisions andthere was increasing confidence that fewoutbreaks were being missed . On the assump-tion of an average of 4 cases per outbreak, itwas calculated that there were perhaps 150-175 infected villages in the entire country .Dhaka was free of smallpox, as were mostsubdivisions of Rajshahi and ChittagongDivisions. To ensure a closer supervision ofactivities throughout the country, pro-gramme staff decided in October to set up 25district surveillance teams, I for each of 19districts and an additional team for each of the6 largest districts. Each team, which consistedof 5 persons, led by a health inspector, wasgiven transport (a motor vehicle, a motorcycle or a boat) .

The plan experienced a serious setback,however, when in November, the govern-ment decided to suspend health activitiestemporarily in order to reorganize the healthservices . The field staff of the hithertoautonomous malaria eradication programmewere to be merged with other health workersinto a single integrated health care service .The new workers were to be called "familywelfare workers", each assuming responsi-bility for a specific geographical area contain-ing approximately 5000 people. The tasksassigned to them included preparing indivi-dual family health cards, registering marriedcouples and births, performing smallpox vac-cination, searching for cases of malaria andsmallpox, and distributing vitamin A capsulesand contraceptives, as well as providinghealth education and family-planningmaterials.

The integration of all health services hadlong been a tenet of WHO but practicalapproaches to its accomplishment had neverbeen satisfactorily elaborated . Bangladesh'sexperience did not provide a model. A train-ing programme was hastily concocted and, fora period of 4 weeks, virtually all health staff

Division/districtPopulation(thousands)a

1974

Jan. Feb. March Apr. May J une July Aug . Sept. Oct. Nov. Dec .

Dhaka:Dhaka 8 875 15 25 17 26 19 7 4 3 I 4 5 5Farldpur 4 735 22 10 17 27 20 8 5 6 I 0 0 0Mymensingh 8 825 103 173 312 382 342 257 232 149 78 51 62 97Tangail 2 425 0 15 19 24 20 23 5 12 6 3 2 0

Khulna:Barlsal 4 580 3 4 4 I I 0 0 I 0 0 0 0Jessore 3 880 8 14 10 13 3 0 2 0 0 0 0 0Khulna 4 150 4 II 15 15 8 I 0 0 0 0 0 0Kushtla 2 195 4 II 10 2 I 0 0 0 0 0 0 0Patuakhall 1 750 6 35 33 10 9 10 6 3 I 0 0 0

Chittagong :Chitcagong 5 025 0 0 0 0 0 0 I 3 3 I 0 0Chittagong Hill

Tracts 590 0 0 0 0 0 0 0 0 0 0 I 0Comilla 6 785 I 2 5 2 I I I I 2 2 0 INoakhall 3 770 I 2 I 0 0 0 0 0 0 I 0 0Sylhet 5 550 15 12 10 2 2 7 2 10 13 2 2 0

RaJshahi :Bogra 2 600 42 44 50 43 39 II 8 8 4 0 I 12Dlnajpur 3 000 2 13 18 19 37 17 17 II 7 I I 9Pabna 3 185 3 3 6 5 I 0 I 5 I I 0 0RaJshahi 4 975 46 38 69 100 120 III 75 29 8 3 0 0Rangpur 6 350 34 110 157 278 245 124 87 39 30 22 56 99

Total 83 245 309 522 753 949 868 577 446 280 155 91 130 223

Table 16 .12 (continued)

except smallpox surveillance teams werewithdrawn from the field for training. Theyreturned to the field to begin a whole range ofnew and unfamiliar activities for which fewof the necessary supplies were provided . Theirfirst task, which required some 2 months tocomplete, was to prepare a separate healthcard for each family on which the name andage of each family member were to be listed .Despite the integration of field staff, how-ever, 2 separate supervisory structures wereleft in place : the malaria eradication pro-gramme structure and the previous healthservice structure. Former malaria eradicationstaff and health service staff looked to theirrespective former supervisors for direction .The entire health service, which had not beenfunctioning well, deteriorated further ; manyemployees abandoned their jobs and returnedto cultivating their small plots of land .

All activities-case detection, containmentand vaccination-sharply diminished afterNovember, but despite less adequate report-ing by the health staff the number of caseswhich were detected doubled betweenOctober and December . Smallpox cases,widely but sparsely distributed throughoutthe country immediately after the monsoon,

16. BANGLADESH

827

suddenly began to occur in large numbersin the northern districts of Rangpur andMymensingh (Fig. 16.11), both of which, upto then, had been free from the disease .

In December 1973, the surveillance systemwas modified to enumerate "infected vil-lages" as well as the numbers of cases anddeaths, a practice that had been adoptedearlier in the year in several states of India . InBangladesh, each village was designated in-fected until 6 weeks had elapsed after theonset of the last case . (India continued to use a4-week interval until later that year .)

During the first 4 months of 1974, thenumber of infected villages increased from309 in January to 949 in April (Fig . 16.12 ;Table 16.12). Rangpur and MymensinghDistricts accounted for 660 (69.5%) of thetotal. In April, Khulna Division, which hadbeen the epicentre of smallpox after thereturn of the refugees, had only 41 infectedvillages. The concentration of resources andsupervisory personnel in 1972-1973 in theinitially heavily infected areas had beenremarkably successful in stopping spread, butthe programme in other areas had conse-quently received less attention . With thewithdrawal of health staff from the field and

1975Division/district

Jan . Feb. March Apr. May June July Aug . Sept. Oct. Nov . Dec.

56 100 159 211 185 108 27 6 4 0 0 0Dhaka:Dhaka

8 39 81 120 63 23 10 4 0 I 0 0 Faridpur271 349 349 193 69 24 10 2 0 0 0 0 Mymensingh

2 8 15 17 15 3 0 0 0 0 0 0 Tangail

4 13 26 41 24 23 18 5 4 I I 0Khula:

Barisal0 0 I II 16 7 I 0 0 0 0 0 Jessore

I 2 6 7 4 2 I 0 0 0 0 0 Khulna0 0 7 30 13 8 2 0 0 0 0 0 Kushtla0 0 I 3 I I 0 0 0 0 0 0 Patuakhali

0 2 5 4 0 I 10 4 3 I 0 0Chlttagong :Chlttagong

0 0 0 0 0 0 I 0 0 0 0 0 Chlttagong Hill

7 40 78 99 108 46 7 0 5 0 0 0Tracts

Comilla0 II 24 50 32 13 9 3 I 0 0 0 NoakhaliI 5 15 124 210 150 29 13 0 0 0 0 Sylhet

65 108 205 215 95 22 1 0 0 0 0 0Ralshahl :

Bogra10 28 36 55 25 12 2 0 0 0 0 0 Dinalpur0 I 3 12 17 9 0 I 2 0 0 0 Pabna2 4 13 39 10 3 0 0 0 0 0 0 Ralshahl

145 127 108 54 32 14 0 0 0 0 0 0 Rangpur

572 837 1 132 1 280 948 476 131 38 19 3 I 0 Total

828 SMALLPOX AND ITS ERADICATION

Fig . 16 .11 . Bangladesh : villages in-fected with smallpox in 8 monthsbetween December 1973 and Sep-tember 1975 .

the subsequent confusion accompanying thereorganization of health services, a po-tentially manageable situation had developedinto a major problem .

AN EMERGENCY PLAN FORSMALLPOX CONTROL,

APRIL 1974 JANUARY 1975

By April, it was apparent to everyone thatthe integrated health service scheme wasachieving little. A redefinition of the respon-sibilities of supervisors and workers and of themanagement structure was required . Accord-ingly, on 9 April the government issued adetailed "Emergency Plan for SmallpoxEradication under the Integrated Health andFamily Planning Programme", of which animportant component provided for unifieddirection of the health services . Dr Mah-boober Rahman, former director of the suc-cessful national malaria eradication pro-gramme, was asked to supervise all health ac-tivities, including smallpox eradication . With-in the new administrative structure, responsi-bilities specific to smallpox eradication were

16. BANGLADESH 829

Plate 16 .6 . A : Surveillance during the monsoon season was an especially arduous task as streams washed outroads, and foot-bridges often consisted of little more than a single bamboo pole . B : Alan H . Schnur (b . 1948)served as a US Peace Corps volunteer with the smallpox eradication programme in Ethiopia from 1971 to1974 before being recruited as a WHO consultant for service in India and Bangladesh .

defined. For operational purposes, new postswere created for staff at subdivision and thanalevels . Civil surgeons, responsible for healthmatters in the subdivisions, were requestedto appoint an area smallpox eradicationofficer for each of the 57 subdivisions and athan smallpox eradication officer for each ofthe 424 thanas . In some areas, the incumbentswere health services staff and in othersmalaria eradication staff . To assist familywelfare workers in containment measures andto improve liaison with villagers, the orderalso authorized the temporary appointmentand remuneration (6 takas, or about US$0.75, per day) of an emergency field workerfor each outbreak . The field workers were tobe recruited and trained in the villages . Theemployment of emergency field workersafforded an unexpected bonus in that theyprovided temporary accommodation in thevillages for smallpox programme staff .

When a case of smallpox was discovered ina village, the family welfare worker was tocease other duties and initiate containment,with the help of the emergency field worker,and to inform his supervisors. The family

83 0

1400-

800-

600-

400-

I M M J S N


1974

1975

Fig . 16 .12 . Bangladesh : number of smallpox-infectedvillages, by month, 1974-1975 .

welfare worker was to reside in the infectedvillage for not less than 10 days and tovaccinate all its residents as well as all personsliving within a half-mile (800 metres) radius .The newly designated than smallpox eradi-cation officers were given the responsibilityfor organizing and coordinating all outbreakcontainment programmes . The area smallpoxeradication officer was required to visit eachthana not less than once a month and to send aweekly progress report to Dhaka .

A monthly national meeting of all areasmallpox eradication officers was institutedto review progress and to decide on plans forthe next month . As was the case in India, themeetings proved to be especially valuable inmotivating staff, in providing continuingeducation and in allowing for an ongoingappraisal of progress and any necessaryredirection of the programme .

Each week an epidemiological report ofnewly detected cases and deaths was compiledat the subdivision level and sent by telegramto the national headquarters . A more detailedwritten report was prepared every month .

Provision needed to be made for theisolation of patients in the densely crowdedareas of Bangladesh. Here it was a moredifficult problem than in many other parts ofthe subcontinent . In rural areas, the patientscould be isolated in their houses, but in theurban slums and in refugee resettlementcamps, they had to be isolated in a specialfacility. In the cities and towns of Khulna,Chittagong, Sylhet, Rajshahi and Dhaka,there were infectious diseases hospitals whichprovided for the isolation of cases but, as

J M M J 5 N

elsewhere, they more often became centresfor the dissemination of smallpox . Hospitalsuperintendents rarely ensured that patientsand visitors were vaccinated on entry . Conse-quently, smallpox eradication programmestaff were obliged to organize and staffvaccination check-points at each hospital,sometimes with local police support. Inheavily populated areas in which there wereno hospitals, isolation wards or camps wereset up in government buildings or even intents, if necessary .

With 10 500 family welfare workers in thefield, a defined supervisory and reportingstructure, 25 special motorized surveillanceteams, and 12 WHO epidemiologists, itseemed all but certain that transmissionwould be interrupted during the monsoonand post-monsoon period . Just 4 years pre-viously, with far fewer surveillance teams,assisted by only 2 WHO epidemiologists, anda much less effective reporting system,transmission had been interrupted in lessthan 6 months.

The number of infected villages fellsteadily, from 949 in April to 280 in August,of which 217 (78%) were in the northerndistricts of Rangpur, Rajshahi and Mymen-singh. Even the distribution of the remainingoutbreaks, similar to the pattern in 1970,suggested that the situation in 1974 mightreplicate that obtaining in 1970 . The numberof cases being detected remained high 1069

Plate 16.7 . Mahboober Rahman (b . 1933), for-merly director of the national malaria eradicationprogramme, assumed overall direction of the inte-grated health programme in April 1974 and broughtorder to a chaotic administrative structure .

16. BANGLADESH

in August compared with 2110 in April was decided in August to offer a reward of 50(Table 16 .13) but detection was occurring takas (about US$6 .50) to anyone who de-earlier and more than 50% of all outbreaks tected an outbreak. The system had provedconsisted of only 1 or 2 cases . As an incentive successful in many states of India and itsfor family welfare workers to report cases, it

application at this time in Bangladesh seemed

2 .

PEOPLE'S RAPUBLIC OF BANGLADESH-MINISTRY OF HEALTH AND FAMILY PLANNING- INTEGRATEDHEALTH SERVICES-SMALLPOX ERADICATION PROGRAMME

AREA SMALLPOX OFFICER'S SMALLPOX MONTHLY REPORT

DISTRICT BOGP1 AREA BOGRA MONTHMAY '74

1 .

Thane report of smallpox infected villages

Note : A village is designated as smallpox infected from date of detection untilsix weeks after the last date of attack at which time the village must becertified free by field visit of District level personnel (CS, CNCH, SDMCH,MY4EEO, ASO, Surveillance Team)

IF NO SMALLPOX INFECTED VILLAGES CHECK BOX /

AREA SMALLPOX OFFICER FIELD VISITS DURJNG MONTH

Number of visits to newly infected smallpox villages28Number of follow up visits to old smallpox villages 62Number of visits to investigate villages where Nildiagnosis of rash not smallpox

Signed Area Smallpox OfficerDate 10.6 .74

Plate 16 .8 . Bangladesh : example of monthly smallpox report .

831

NUMBER OFVILLAGESINFECTED1ST OF MONTH

NUMBER OF(+) NEWLYDETECTEDSP VILLAGES

'.FUNBER OF(-) SP VILLAGESP,ERTIFIED'5P FREE

NUMBER OF(-) SPVILLAGESEND OF MONTH

NUMBER OFACTIVECASESLAST VISIT

1 . JAIPURHAT 1 0 1 0 0

2 . SHERPUR 19 6 15 10 13

4 4l

1 7 5

0 0 1) 0 0

6 2 6 2 0

5 1 4 2 1

6 5 4 7 12

0 10 3 7 2

2 4 2 4 3

10 .

TOTAL

I 43 32 -

36 39 36

8 32

Table 16 .13. Bangladesh : number of reported casesof smallpox, by division and by month,1974

appropriate . Additional help was provided bythe United Nations Relief Operation, Dacca(UNROD), which was in the process ofconcluding its activities ; it turned over to thesmallpox eradication programme a centraltransceiver and 8 field radios . Six more fieldradios were added later and thus a valuablenetwork of communication was establishedbetween the smallpox eradication pro-gramme headquarters and epidemiologists inthe field.


In October 1974, only 91 infected villagesremained, and periodic village-by-villagesearches were initiated. A similar searchprogramme had begun in India a year beforeand more recently in Pakistan, but suchsearches in Bangladesh had not been possiblebefore late spring because of the turmoilcaused by the reorganization of the healthservices. During the monsoon months of1974, national and WHO staff alike felt thatsearches were not required, in view of theexistence of a unified health service and theassignment of a family welfare worker in eachpopulation unit of 5000 persons . Since eachworker was expected to visit every housewithin his jurisdiction every 5 weeks and wasmotivated by the promise of a reward of 50takas (about 5 days' pay) for the discovery of acase, it seemed unlikely that many outbreakswould be missed . The initiation of a searchprogramme in October was intended as thefirst stage in the development of a scheme toconfirm that transmission had been inter-rupted rather than as an operational tool todetect cases, as in India.

The late summer months, however, hadbrought still another tragedy to Bangladesh .The most extensive and severe floods formore than two decades swept through major

Plate 16.9 . When isolation of smallpox patients in their own houses was not possible, hospitals were used,some of which were specially constructed, as was this one in Sylhet District .

Month Chittagong Dhaka Khulna Rajshahi Total

January 16 763 132 521 1 432February 189 668 351 899 2 107March 96 613 298 635 1642April 25 1410 207 468 2 110May 4 1 225 183 2 525 3 937June 50 776 21 874 1721July 73 483 13 512 1081August 91 447 117 414 1 069September 98 130 5 128 361October 39 191 0 78 308November 18 139 3 203 363December 6 222 0 126 354

Total 705 7 067 1 330 7 383 16 485

An Episode Indicative of Frustration and Misguided Effort

The climate of feeling in Bangladesh oscillated between optimism that theinterruption of transmission was only months away, an opinion prevailing in October andNovember 1974-to profound pessimism and doubt that eradication could ever beachieved . The early months of 1975 represented an extreme of the latter mood . Frustrationand exasperation sometimes compromised judgement, as was exemplified in Bogra, amunicipality and district in north-central Bangladesh .

By the autumn of 1974, Bogra District, once heavily infected, had interrupted smallpoxtransmission at the conclusion of a thoroughly competent but exhausting campaign .However, in late December 1974 and in January 1975, outbreaks began to recur followingimportations from the famine-stricken area to the north, and cases were detected in themunicipality . The smallpox eradication staff were concerned about the prospects of widedissemination of smallpox from an urban area and decided that a mass vaccinationcampaign throughout the city was urgently required. While such a scheme might seemattractive, similar efforts in the past had always proved costly in time and manpower andwere rarely successful, in part because of the continual migration of the population .Following a 10-day house-to-house mass campaign, assessment revealed that only 50% ofthe inhabitants had been vaccinated . A second campaign proved no more successful . Yet athird campaign was organized, this time employing 3 WHO advisers who had beenwithdrawn from supervision of outbreak containment in rural areas . During the course of2 weeks, with the staff working 15 hours a day, 7 days a week, a coverage of 93% wasfinally achieved . No sooner had this task been completed than a major privately sponsoredfair opened which drew upwards of 20 000 visitors per day . Thenceforth outbreaks beganto recur throughout the district, of which most could be traced to contact with infectedpersons at the fair. Efforts were made to persuade the organizers of the fair to close it downor to allow all those attending it to be vaccinated when they bought their tickets . Theentrepreneurs, however, were also the principal civic officials and they were not anxious todiscourage attendance by making vaccination a requirement . Six weeks of discussion wereto elapse before the fair was finally closed by order of the central government. By then,Bogra was the world's second most heavily infected district . Not until May did smallpoxbegin to subside .

parts of the northern districts, where most ofthe remaining infected villages were located .Some refugees began to move from the area atthat time, but in November and December,the season when crops were usually harvested,severe famine struck .

During the first week of October, only 24cases were detected, but in succeeding weeksthe numbers began to increase sharply. Bymid-December, there were 168 infectedvillages, of which only 23 were outside thetwo flood-afflicted districts, but 20 outbreakshad occurred as a result of spread from thesedistricts. Outbreaks were being detectedunusually rapidly 55% within a week ofonset and 88% within 3 weeks . The contain-ment of outbreaks was not optimum but, still,in 84% of them no cases were detected morethan 21 days after the onset of the first case .

16. BANGLADESH 833

Because of population movement andcrowding, however, smallpox spread explo-sively . In Rangpur District, a beggar living ina market-place died of smallpox on 2 Decem-ber ; 48 second generation cases in 18 villagesoccurred among those who had visited themarket. In Faridpur District, south of Dhaka,a fatal case in a village was the source of 37second generation cases in 4 different villages(WHO/SE/74.65, Rangaraj & Yusuf) . In mid-December, cases were discovered amongfamine-stricken refugees in Dhaka and inthe district towns of Bogra and Mymensingh .Efforts to control the spread of smallpoxamong refugees sleeping shoulder to shoulderin the extensive slum areas of the cities was anall but impossible task.

The occurrence at this particular time ofthe most widely celebrated Muslim holiday,

8 3 4 SMALLPOX AND ITS ERADICATION

Plate 16.10 . Increasing numbers of staff and additional resources were provided to the programme inBangladesh during 1974-1975 in a final intensive effort to eradicate smallpox from Asia . A: Andrew N . Agle(b. 1937), a veteran of smallpox eradication programmes in western and central Africa, 1966-1971, then inAfghanistan, 1972-1974, was the WHO administrative officer in Bangladesh . B : Jane Brown (b . 1942), secondedfrom WHO Headquarters for 6 months, directed radio communications . C: CARE, a private charitable organ-ization registered in the USA, built an operations building, "Smallpox Zero", to house additional programmestaff. Additional buildings were constructed for the storage of parts and a garage for maintenance of a newfleet of Indian-made jeeps .

the Eid festival (Id ul Fetre), further com-pounded the problem, since this feast was theoccasion for large family gatherings, entailingextensive travel .

Meanwhile, in Nepal and Pakistan, trans-mission had been interrupted ; in India, theincidence of smallpox and the number ofinfected villages were declining steadily . Itbecame increasingly apparent that the courseof events in Bangladesh would determine thesuccess or failure of the endeavour toeradicate smallpox from Asia. Additionalinternational staff were assigned tostrengthen the programme in Bangladesh,the number increasing from 8 in June 1974 to21 in January 1975 . But smallpox continuedto spread. As has already been mentioned,only 91 villages were infected at the end ofOctober, but the number had increased to 130by the end of November, to 223 by the endof December, and to 572 by the end ofJanuary. This last number was almost twicethe figure recorded for the correspondingperiod one year earlier .A catastrophe from the viewpoint of

smallpox eradication occurred when thegovernment decided that urban busteesshould be demolished. In a matter of a fewweeks, bulldozers and police dispersed anestimated 50 000-100 000 additional refu-gees from the cities throughout the country-side. Some had smallpox or were thenincubating the disease . A frustrated, demoral-ized staff was called upon to regroup and tomount yet another national effort .

NATIONAL MOBILIZATIONFOR SMALLPOX ERADICATION,

FEBRUARY 1975

Beginning in December 1974, nationalhealth personnel and WHO staff stationed inBangladesh, New Delhi and Geneva metrepeatedly to decide on a revised strategy andadditional measures that might be taken.With the extensive continuing movement ofpopulation, it was apparent that effortswould need to be greatly intensified, and thatsubstantial additional funds would be re-quired. However, WHO's Voluntary Fundfor Health Promotion, as well as discretionaryfunds in the WHO regular budget, had beenexhausted in strengthening the programmein India . Additional support would have to besought, but this would require the approvalby the Bangladesh Planning Commission of a

16. BANGLADESH 835

revised plan of operations and the concomi-tant financing. Although the Secretary ofHealth and the WHO Representative inBangladesh supported the programme, theywere of little help. Both were adamant thateradication could be achieved only through anational mass vaccination campaign conduct-ed through the basic health service structure .They were not persuaded by the argumentthat this would be futile in an already wellvaccinated population, nor could they acceptthe fact that the newly created basic healthservice structure had all but ceased tofunction . Fortunately, the recently appointedprincipal health adviser to the PlanningCommission, Dr Mohammad Ataur Rahman,had a far better and more realistic under-standing of the problem and the resourcesneeded. Dr Rahman was a knowledgeable andskilful administrator and virologist who hadplayed a key role in the development ofsmallpox vaccine production in Dhaka, andsubsequently had closely followed the pro-gress of the eradication programme. Throughhis efforts, the Planning Commission waspersuaded to direct an appeal for assistance toa number of international agencies . TheSwedish International Development Author-ity responded as it had in India-mostrapidly and generously, making available US$3.5 million. Significant contributions werealso made by Canada, Denmark, Norway andthe United Kingdom .

In February 1975, a presidential directivewas issued which declared smallpox to be anational emergency and ordered the mobili-zation of all available resources to assist in itseradication . Thirty-five jeeps of Indian manu-facture were hurriedly procured and driven toBangladesh ; others were loaned from otherprogrammes . Additional radios, motor cycles,boats and outboard motors were obtained . MrRodney Hatfield, a young volunteer fromOXFAM (a charitable organization regis-tered in the United Kingdom), assumedresponsibility for transport maintenance andrepair ; an old garage was transformed into afully equipped workshop with a staff of 12mechanics ; and numerous Ministry of Healthvehicles that had long been in disrepair weremade roadworthy . An operations buildingwas rapidly constructed by CARE (a chari-table organization registered in the USA),using a new technique of jute and fibreglassconstruction. To coordinate field operations,WHO's former senior smallpox adviser inAfghanistan, Dr A . G. Rangaraj, joined the

8 3 6 SMALLPOX AND ITS ERADICATION

Plate 16 .11 . A: Small motor cycles were very useful for travelling around the country as they used littlepetrol, could be readily carried on boats and could be used on the narrow footpaths connecting villages . B: Thesmallpox programme motor park in Rangpur District in September 1975 .

Table 16 .14. Bangladesh : average numbers of international staff' and national epidemiologists employed inthe smallpox eradication programme, by 3-month period, 1972-1977b

1972

1973

16. BANGLADESH

1974

1975

a In all, 207 International staff from 28 countries served in Bangladesh at some time during this 4-year period .b From Joarder et al . (1980) .

staff. Dr Stephen Jones and Dr DonaldFrancis came from India to assist in adaptingthe most effective techniques employed thereto conditions in Bangladesh .

Numerous other WHO staff and consul-tants were urgently recruited from countriesaround the world (Table 16 .14), many of themhaving served in Africa, South America andother parts of Asia . It was a group remarkablydiverse in nationality, being composed ofBrazilian, British, Czechoslovak, Egyptian,French, Soviet, Swedish and Swiss citizens .The Center for Disease Control and OXFAMwere especially helpful in recruitment . Newcolleagues arrived every 2 weeks, to rendez-vous in New Delhi for a Monday briefing. OnTuesday they flew to Dhaka and over the next3 days received intensive field and classroomtraining before being dispatched to the field .Because there was a shortage of hotel accom-

837

modation, a house was leased which couldaccommodate 18 persons-unofficially calledWHOSE House (an acronym for WorldHealth Organization Smallpox Eradication) .By May, 71 international staff were workingin the field, and during that month therecruitment of Bangladeshi epidemiologistsfrom universities and other settings wasinitiated.

A formidable challenge was presented bythe administrative coordination and financialmonitoring of a programme which, operatingwith US$12 000 a month in September 1974,was spending US$125 000 a week by February1975. This daunting task was capably handledby Mr Andrew Agle, who had served in thewestern Africa and Afghanistan eradicationprogrammes and had joined the Bangladeshprogramme staff in September 1974 . He andMr A. Alim Mia, a Bangladeshi administrator

Plate 16.12 . WHO consultants . A: Pierre P .L . Claquin (b. 1947), a French epidemiologist, engaged for3 months in March 1975, eventually spent a total of 27 consultant months in Bangladesh . B: T . Stephen Jones(b . 1941) was one of the many epidemiologists provided to WHO by the Centers for Disease Control in theUSA. He served for 3 months in India in 1974 before spending 3 months in Bangladesh in 1975 .

3-month periodInternational International International International National

January-March 5 3 9 41 0April-June 4 5 10 68 5July-September 2 6 11 64 25October-December 2 7 14 40 25

83 8

who had served with the programme since itsinception, dealt with a considerable array ofproblems, both expected and unexpected . Oneof the more vexing was that of disbursingfunds to the field epidemiologists for thepayment of temporary staff to cover boardand lodging, as well as petrol and repairs . Thetelegraphic transfer of funds to bank branchesin peripheral areas would have been the mostlogical way of coping with the problem, butwas technically impossible for many months .The only workable alternative approach wasto disburse the funds at monthly meetings ofsupervisory field staff. However, the largestbanknote then available was a 10-taka note(about US$1.25) and, during the intensiveperiod of activity, field staff were receiving30 000 takas or more each month . The inevi-tably large bundle of banknotes was difficultto handle, but the problem was solved byusing capacious gunny sacks and carryingthem into the field tied to the back of a motorcycle ; although there was no attempt atconcealment, thefts never occurred .

Under the national mobilization plan, andwith many additional field epidemiologistsavailable, containment measures were greatlyexpanded from previous strategies whichcalled for one family welfare worker and oneemergency field worker to vaccinate everyoneliving within a half-mile (800-metre) radiusof each case. The containment meas-ures were basically the same as those that hadevolved in India .A worker who discovered a case was

instructed to isolate the patient immediately


Fig . 16 .13 . Bangladesh : containment of smallpox outbreaks .

Infected houseIsolate patientEnumerate and vaccinate residents and visitorsTwice-daily inspection for fever and rashHouse guards (24 hours)

Zone A (100 yards)Enumerate and vaccinate residents and visitorsTwice-daily inspection for fever and rash

Zone B (100 yards to %, mile)Enumerate and vaccinate residentsDaily house check for fever and rash

Zone C (% mile - 2 miles)Check every 5 days for fever, rash, or smallpoxinformation

and to vaccinate all household members. Aresident supervisor was appointed, usually thehealth worker in the area, who recruited 4house guards responsible for keeping thepatient in the house and for vaccinating allvisitors. Food and water were provided ifneeded. (For the recording of activities,special "house guard books", such as had beenused in India, were introduced in April.) Theresident supervisor then hired 4-6 emergencyfield workers at 6 takas each a day. He trainedthem to register and vaccinate all residentsand visitors within a half-mile radius of theinfected house, and to search for cases in allmarkets, schools and houses within a 2-mile(3.2-kilometre) radius (Fig . 16.13). Whenthese tasks were completed, the workersrevisited all persons within the half-mileradius to detect and vaccinate any newcomersor others who had been missed during theintensive vaccination phase.

Resident supervisors were provided with a"containment book" in which the followinginformation was recorded :

•

a list of patients and the stage of theirillness ;•

information pertaining to the source ofinfection and contacts of the cases ;• a list of household members and temporaryresidents of Zones A and B (i .e., those livingwithin a 100-yard (90-metre) and a halfmile (800-metre) radius, respectively, of theinfected house) ;•

a list of staff and work schedules for allinvolved in containment ;

• a record of visits of supervisory staff fromthan, subdivision and district levels ;•

a map of the outbreak area showing eachhouse, all houses being numbered ;• a record of all financial transactions-e .g .,payments to emergency field workers forpetrol, etc .

Check-points were set up on strategic pathsand roads to collect information about otherareas in which cases might exist and tovaccinate passers-by .

The source of infection of each case wasexamined and all possible contacts werevaccinated. Any contact with fever was iso-lated and members of the household werevaccinated. Whenever the suspected source ofinfection was in another than, or whenever acontact had left the village for another area, aspecial message (cross-notification) was sentby messenger, telegram or radio. District,subdivisional and thana officers, surveillanceteams and epidemiologists made periodicsurprise visits to assess the efficacy of thework.

At the monthly meetings of supervisoryfield staff, problems were reviewed and proce-dures changed as required . An example of anunexpected event was the discovery by aBangladeshi epidemiologist, Dr M . A . Sabour,that in 11 out of 17 outbreaks for whosecontainment he was responsible, cases wererecorded 15 days or more after containmenthad begun . As he discovered, most of the caseswere relatives of patients and should havebeen identified and vaccinated . He learned,however, that when a family in an infectedhome was asked to give the names of all recentvisitors, they omitted to mention the names ofrelatives-since relatives, in their culture,were not considered to be visitors . The steadyimprovement of containment could bemeasured by the diminishing proportion ofoutbreaks in which cases occurred more than15 days after detection of the outbreak (Fig.

16. BANGLADESH

Dr A. B. M. Kamrul Huda

Dedication and sacrifice were characteristic of many who served the programme, and afew gave their lives . One young medical officer who did so was serving at the time as theSubdivisional Medical Officer of Health in Chittagong . He was notified late one night ofpossible smallpox on an offshore island and arose early the next morning to take a ferry tothe island . Because of high winds the ferry was cancelled . Dr Huda was anxious toinvestigate the rumour and took a small local boat instead . The boat capsized en route andDr Huda drowned . He died on 3 March 1975, leaving a wife and two young children.

16.14). In November, cases occurred in 27%of the outbreaks more than 15 days afterdetection ; by June, the proportion was lessthan 10% (Foster et al., 1980) .

With increasing numbers of epidemiolo-gists in the field to investigate the source ofoutbreaks, to trace contacts who might haveleft the scene of an outbreak and to discoverrumours of outbreaks as yet undetected, manypossible additional cases were identified inmore distant areas. The radio network wasused extensively to forward such informationfor other staff to investigate . Beginning inFebruary 1975, each cross-notification wasrecorded and the results of the field investiga-tions were tabulated (Table 16 .15). BetweenFebruary and December 1975, 1468 cross-notifications were transmitted, leading to thediscovery of 28 previously unknown out-breaks not a large yield for the number ofreports transmitted and investigatedbut important, nevertheless, in hasteningthe interruption of transmission . Three addi-

30

25

E10p

C

U 5

262 514711

994812

406

14245 15

131

0N D J F M A M J

J1974 I

1975A

839

25

Fig . 16 .14 . Bangladesh : number of smallpox out-breaks per month, November 1974-September1975, and the proportion with cases occurring 15days or more after the outbreak was detected andin which containment measures were considered tohave failed .

8 4 0


Table 16.15 . Bangladesh : cross-notifications of suspected cases of smallpox within the country, 1975

b Totals for May-December only .

tional outbreaks were discovered throughnotifications received from India .

SPECIAL SEARCHPROGRAMMES

A special 6-day village-by-village search forcases had first been organized in October1974 and a second was conducted in Decem-ber of that year . It was believed that if thefamily welfare workers could be carefullyinstructed to perform well only one of theirmany assigned functions i .e ., that of small-pox case detection during a 6-day tour of theirarea the results would be better than if thisactivity were but one of the numerous tasksrequired of them . Thana supervisors reportedthat the searches in October and Decemberwere reasonably successful but assessment bydistrict and subdivision staff and surveillanceteams indicated that there were large areas inwhich no search had been carried out and fewin which searches had been conductedcompetently .

With additional staff to assist in super-vision, some of whom had had experiencewith this technique in India, more energeticsearch programmes were introduced in April1975 ; these were repeated every 4-6 weeks.Approximately 14 500 staff were engaged ineach search, following special training pro-grammes at each operational level.

The workers were asked to visit markets,tea-stalls and every 20th house. They wereinstructed to show the smallpox recognitioncard at each location, and ask the viewerswhether they recognized the disease-whichmost of them did. The health workers were

told to inform their audience of the rewardfor reporting an unknown case of smallpoxand where to report it ; to record any informa-tion obtained about persons with rash andfever, including the deaths of any of them ;and to report cases to the thana supervisor .

After each survey, 1500 villages wererandomly selected to assess the efficacy ofsearch. Assessment in Bangladesh was greatlyfacilitated by the fact that every house in thecountry was numbered a practice begun bythe staff of the malaria eradication pro-gramme and kept up by the smallpox eradica-tion personnel. An assessment of the results ofthe April search revealed that surprisinglyfew villagers knew of the reward for report-ing a case . On further investigation, it wasfound that health workers, wanting to claimthe 50-taka reward for themselves, did notpublicize it . This situation was corrected inMay, when the reward was offered both to theperson who reported the outbreak and to thefirst health worker to confirm it . The Aprilassessment showed that only 30% of villagersknew of the reward, but by September thisproportion had increased to 70% .

In contrast to the experience in India, thenumber of outbreaks discovered during eachsearch was not high (Fig . 16 .15). However, inIndia, the reward was not offered until manysearches had been conducted, while in Bang-ladesh its existence was announced evenbefore the first searches began . The searches inBangladesh were more effective in increasingpublic awareness of the reward and in stimu-lating reporting than in detecting outbreaks .As an illustration, a review of the last 119outbreaks which occurred showed that 55(46%) had been detected by reports from the

Number ofMonth

reportstransmitted

Smallpoxa Investigation results

Newoutbreak

Knownoutbreak

ChickenpoxOther diagnosisor no disease

Casenot found

Noreport

February 91March 146 9 15April 72May 104 7 14 1 58 10 14June 129 5 IS 15 73 12 9July 134 5 II 16 86 II 5August 233 2 10 32 133 28 28September 294 0 1 37 134 50 72October 103 0 0 0 93 0 10November 86 0 0 0 77 0 9December 76 0 1 0 62 I 12

Total

1 468 28 67 101b 716b 112b 159b

a . = data not recorded .

400300200

100Y 80

6040

0 30

0 20Lv

10E 8Z 6

432

SearchI

Search

Search

Searchi

16 18 20 22 24 26 28 30 32 34 36 38 40 42Week number, 1975

Fig . 16 .15 . Bangladesh : number of outbreaks de-tected by week, 1975 .

public and 37 (31 %) by surveillance teams(Fig. 16.16) .

The number of personnel engaged in theprogramme was far larger than it had everbeen. An estimate during the 3-month periodof greatest activity revealed that an average ofalmost 12 000 persons were working each day(Table 16 .16).

Between February and April, the numberof reported cases steadily increased, from 1703in February to 2467 in March and to 3948 inApril. Smallpox appeared to be as great aproblem in 1975 as it had been in 1974although, on the basis of later surveys, it wasestimated that 83 % of all cases were reportedin 1975 compared with only 49% in 1974(Hughes et al ., 1980).

The occurrence of epidemic smallpox ex-tending throughout Bangladesh for a fourthyear was politically uncomfortable for theSecretary of Health, a former surgeon. He

16. BANGLADESH 841

Fig . 16 .16 . Bangladesh : source of report of the last119 outbreaks of smallpox .

fully accepted the idea of mass vaccination butwas uneasy about the concept of a programmefor detecting cases and containing outbreaks .The success of surveillance-containmentoperations in 1970 did not convince him . Hispersonal experience with smallpox control inthe Ministry had been confined to the periodsince Bangladesh's independence, and for thelast 4 years optimism had been expressedby the staff during and immediately after themonsoon each year, but epidemics and emer-gency programmes inevitably followed in thespring. For advice he turned most often to theWHO Representative in Bangladesh, a publichealth physician but one who understoodneither smallpox epidemiology nor the eradi-

Table 16 .16 . Bangladesh: personnel employed during the 3-month period of maximum containment of thesmallpox eradication programme, May-July 1975

a The number of man-days per month totalled 357 400, or an average of 11 913 persons working every day.

Personnel category NumberNumber of days

per man per 3 monthsTotal number of

man-days in 3 monthsa

Headquarters staff 80 75 6 000Epidemiologists 90 80 7 200Area and thana surveillance officers 500 30 15 000Surveillance team members 400 75 30 000Health staff for 2 searches 12 000 12 144 000Containment :

Health staff 1 000 70 70 000Emergency field workers 10 000 90 900 000

Total 24 070 1 072 200

Percentage of outbreaks0

10

20

30

40

50

Public n=55)

Surveillanceteam

n=37)

Healthpersonnel

(n = 21)

Crossnotification

n=2)

Unknown n = 4)

8 4 2


cation strategy any better than the Secretaryof Health. With smallpox incidence rising andwith increasing international interest as towhether Bangladesh could or would be able tostop transmission, tensions were great . TheSecretary of Health and the WHO Represen-tative repeatedly and vehemently demandedthat the surveillance-containment pro-gramme should be stopped and the entirepopulation vaccinated forthwith . Dr Mah-boober Rahman and his national and WHOcolleagues argued that mass vaccination wasfutile, that vaccinial immunity was alreadyhigh and that the surveillance-containmentapproach offered the only possible solution .Indeed, the level of vaccinial immunity, asshown in a 1976 national survey was 91overall .

However, without notice to the pro-gramme staff, the Secretary of Health wouldperiodically order the health staff in a districtor subdivision to stop all other activities andto vaccinate everyone in the area concerned .Usually, this was accompanied by threats ofpunishment if any unvaccinated person wasdiscovered at the end of 7 days or some suchbrief period . After lengthy discussions, theSecretary would eventually be persuaded torescind the order, but, not infrequently, formany days outbreak containment pro-grammes were abandoned and surveillancewas stopped. Further problems occurredwhen the Secretary and the WHO Represen-tative made one of their frequent visits to thefield . The Secretary would announce that onhis trip, he would stop at villages along hisroute and expect to find that every singleperson had been vaccinated . A flurry ofactivity ensued to vaccinate everyone alongthe route he was expected to follow, again atthe expense of outbreak containment mea-sures. An even more serious problem arosewhen he required senior staff to pledge toresign if cases of smallpox were found after acertain date, an action which resulted in thesuppression of reports of cases . The problemwas not finally resolved until April, when theWHO Representative returned to Genevaand was replaced by the able Dr Eung SooHan. The Secretary's continuing concernabout his and his country's image was reflect-ed in May 1975 by his decision not to attendthe World Health Assembly . Instead, hedispatched Dr Rahman to respond to theanxious inquiries he knew would be expressedabout the Bangladesh smallpox eradicationprogramme.

THE FINAL CHAPTER

From April to August, the number ofinfected villages decreased at a substantiallymore rapid rate than in preceding yearsfrom 1280 in April to 131 in July. The staffbegan to chart weekly the number of "activecases" still present-i .e ., the number of casesin which the scabs had not yet been shed . In aprogress report to WHO staff in July 1975,Henderson wrote : "Some years ago . . . we hadplotted progress on a country and provincialbasis, subsequently on a district basis and thenby blocks/thanas. In now monitoring thenumbers of individuals capable of transmit-ting infection, I believe we've reached a finalstage." The last case in India, the last of 32importations from Bangladesh, occurred inMay, leaving Bangladesh the only endemicarea in the whole of Asia. The search in Julydetected 33 outbreaks and that in August only7. With the extensive resources available anda programme functioning so well, the endonce again appeared to be in sight . Therewas, however, one further tragic event .

On 15 August, Sheik Mujibur Rahman, thefirst President of Bangladesh, revered as thefather of the country, was assassinated in amilitary coup . The airport was closed and theborders sealed . Communications by radiowere suspended for 2 weeks and althoughfield staff continued to work, movement inand out of Dhaka was limited . Fearing thatvehicles might be seized, the smallpox eradi-cation staff hurriedly dispersed them from themotor pool to locations all over the area. Fornearly a month, most of the staff remainedapprehensive that civil war might again occurand, with it, the movement of hundreds ofthousands of refugees-and renewed epi-demics of smallpox. India, meanwhile, greatlystrengthened its complement of staff inborder areas. Fortunately, the country re-mained quiet, the monsoon rains were plenti-ful, an excellent crop was harvested and theenormous movement of refugees ceased .

The post-monsoon period was not, how-ever, without incident, as a Japanese scientificteam arrived in Dhaka bringing with them anew laboratory technique for the rapid diag-nosis of smallpox . It was a propitious momentat which to undertake the investigations,since Dr Farida Huq, a highly competentvirologist, was present in Dhaka at that timeand able to perform confirmatory studies onspecimens from suspected cases. The newimmunofluorescence technique seemed capa-

ble of identifying variola virus in pus or scabswithin hours (instead of days) after a speci-men had been submitted . Only 19 villageswere infected in September as the team beganits work, but many of the first specimensexamined were reported as positive for variolavirus. Surveillance teams were then takingmany specimens from cases which they haddiagnosed as chickenpox, simply to confirmby laboratory test that smallpox was notpresent. Many of these specimens were repor-ted to contain variola virus and for weeksconsternation and bewilderment prevailed ascontainment operations were begun and thenstopped in numerous presumed outbreaks .There was a strong suspicion that somethinghad gone seriously awry when immuno-fluorescence staining showed that materialtaken from a boil on the back of one of theWHO advisers contained variola virus. Atechnique which had worked well in thelaboratory had failed when used in the field,and was soon stopped (Tarantola et al., 1981) .

THE LAST OUTBREAK

When the conflicting laboratory and clini-cal data had been resolved, it became clear that

16. BANGLADESH 843

Plate 16 .13 . Smallpox eradication programme offices in the field were simple but functional like this one inChandpur Thana .

smallpox transmission had apparently beenterminated-the last known case having oc-curred on 14 September . Over the succeedingweeks, 8 previously undetected outbreakswere discovered in Patuakhali, Barisal andDhaka but in none had cases occurred after 14September. The monthly programmes of sys-tematic search continued and, except in thesethree districts, independent assessementshowed excellent results . At the beginning ofNovember, civil disorder erupted, with localfighting breaking out in three different partsof the country. The United Nations wassufficiently concerned to recall its personnelto Dhaka. Only the WHO smallpox eradica-tion staff remained in the field . But noadditional cases could be found .

The progress of the smallpox campaign inAsia had been followed closely by the press,which believed, as did the personnel involved,that eradication of smallpox from Asia wasthe most formidable obstacle to global eradi-cation. Early in November, 6 weeks after theonset of the last case, the only active outbreakin Asia was scheduled to be removed from thelist. It was agreed, however, that caution wasrequired and an additional 2 weeks should beallowed to elapse before an announcementwas made. No cases occurred, and on 14

8 4 4

November 1975 WHO announced at a pressconference that 2 months had passed since theonset of the last case in Bangladesh ; and whilethe intensive search for cases would continuein Bangladesh and other countries, there wasat that time no known patient in the whole ofAsia, indeed in the world, with variola major .On the following day, 15 November, theeradication programme's telex control roomreceived the following cable from the denselypopulated Bhola Island, off the southerncoast

"ONE SUSPECT SMALLPOX CASE DETECTED VILLAGEKURALIA [UNION COUNCIL SOUTH DINGALDI [POLICESTATION BHOLA DATE OF DETECTION 14/11/75 DATEATTACK 30/10/75 CONTAINMENT STARTED DETAILSFOLLOW".

(The date of onset was later confirmed to be16 October 1975 .)

A team of epidemiologists immediately leftDhaka for Bhola Island expecting to find amisdiagnosed case of chickenpox . Theyreached the infected house only after a 24-hour journey by speedboat, steamer, jeep,motor cycle and finally on foot. The diagnosiswas not in doubt : it was smallpox, and thiswas confirmed days later by the laboratory .Everyone was concerned. It was November,the monsoon was over, and the season whensmallpox was most rapidly transmitted was athand. If there was one case, there had to beothers in the chain of transmission.

Bhola Island, located at the mouth of theGanges, had a population of 960 000 and anarea of approximately 2600 square kilometres .Regular ferries connected the island with themainland and other islands and these wereheavily used .

In 1970, Bhola had been devastated by atidal wave, which was followed by a reliefoperation that included a smallpox vacci-nation campaign . Because of this, the propor-tion of persons with a vaccination scar washigher than in most of the country. During1974 and 1975, few smallpox cases had beenreported . However, in August 1975, it wasdiscovered that a medical officer had failed toreport known outbreaks . Subsequently, sur-veillance had been reinforced, and since thebeginning of August 141 cases and 33 deathshad been detected. All but 2 of the out-breaks, one of 43 cases and one of 44, hadceased before discovery. Once again, investi-gation revealed the suppression of reports andso, early in October, an additional surveil-lance team had been sent from another area,


the Bhola surveillance team reorganized, andan epidemiologist posted to the island for full-time work .

On 6 November 1975, while conducting asearch of markets, the Bhola surveillance teamreceived information about an outbreak inKathali village . During the course of investi-gating and tracing the sources of infection,the team discovered outbreaks in 3 othervillages with cases extending back to2 March. A search began within a 5-mile (8-kilometre) radius of each of these villages .During a tea break in one of the markets, thesurveillance team obtained information aboutthe death of a person with rash in the villageof West Joynagar, 5 kilometres to the south .

The death had been reported to the thanasmallpox eradication officer, who had sent afamily welfare worker to investigate . Hisconclusion had been that the death was causedby measles. On investigation, the surveillanceteam was in no doubt that it was due tosmallpox. A search revealed an outbreak of 7cases and 3 deaths. One of the patients was aheavily pockmarked 8-year-old girl who in-formed the team that there were other cases inKuralia village, some 200 metres to the westof her house. Investigation there revealed 2cases, one of which was in a 10-year-old boywhose onset of illness was on 6 October andthe other in a 3-year-old girl, Rahima Banu,who had become ill on 16 October .

By the time of investigation, Rahima Banuwas the only known patient with activesmallpox in all of Asia. Accordingly, extra-ordinary efforts were begun immediately tocontain the outbreak and to discover otherpossible cases . The surveillance team whichhad detected the outbreak was soon joined byteams of epidemiologists from Dhaka andother areas . A launch brought vaccine, lighttransport (motor cycles and bicycles), speed-boat engines, drums of petrol, kerosene lan-terns, loudspeakers and other equipment . Thepatient, who still had a few scabs on her legs,was isolated at home . House guards wereposted 24 hours a day ; food and money weresupplied to the family so that no one wouldhave to leave the house. Vaccination of the18 150 people living within a radius of 12miles (2.4 kilometres) of the infected housewas begun immediately. This task includedday and night house-to-house vaccination,the enumeration of every household member,the checking of vaccination results, and thevaccination or revaccination of any new-comers to the village .

16. BANGLADESH 845

Plate 16 .14 . Rahima Banu, a 3-year-old girl from Bhola Island, Bangladesh, was the last case of smallpox in Asiaand the last naturally occurring case in the world of variola major, the more virulent form of the disease . Herillness began on 16 October 1975, approximately 3 weeks before this picture was taken . The depigmentedareas of her skin are sites where lesions were present .

8 4 6


The area within a 5-mile (8-kilometre)radius of the infected house was searchedrepeatedly by successive teams ; each teamsearched for cases with fever and assessed theperformance of the preceding team . The 7markets and 9 schools, as well as all healers inthe area, were visited repeatedly to pick uprumours of other cases. Each house on BholaIsland was searched by health staff under theguidance of epidemiologists and surveillanceteams, which had been allocated specificgeographical areas . This search also coveredall public meeting-places such as markets,schools and tea-shops. Whenever it was re-ported that a member of any household in theoutbreak area had left, the responsible au-thorities were notified so that the personconcerned could be found, vaccinated andkept under surveillance .

A difficult problem was the poor means ofaccess from the centre of the island to theshore, where most of the outlying villagescould be reached only after a difficult journeyby bicycle or on foot. Frequently, the pathsleading to these villages were cut by smallrivers caused by fluctuating tides . The settle-ments along the shore were occupied bylandless peasants or fishermen, who were themost distant from health centres and the leastlikely to be visited by health staff . They weregenerally much less well vaccinated thanother groups and unlikely to report any casesof smallpox . Accordingly, a dispensary-launch began a methodical village-by-villagesearch, which had to be planned daily accord-ing to the tides . Local launches were used also .

A 500-taka (US$33.00) reward was offeredto anyone reporting a case of smallpox . Thiswas widely publicized through the use ofposters, pamphlets, handbills, loudspeakersand, from Dhaka, the press and other media .Check-points were established at such placesas bus stations, ferry docks and crossroads,where travellers converged . Information wascollected about cases with rash and these werechecked by mobile teams .

About 10 kilometres north of the site ofthe outbreak, in Bhola town, a control roomwas established where progress could berecorded on maps and charts . Radio communi-cation was established to permit regularcontact between the control room, thedispensary-launch travelling along the shoreareas, and Dhaka.

The health staff engaged in this outbreakalone (within a 5-mile radius) consisted of3 epidemiologists and more than 40 health

Plate 16 .15 . Mohammed Matiur Rahman (b . 1932),a medical officer with the national programme inBangladesh, questioning villagers about possible small-pox cases during the search on Bhola Island .

staff and temporary workers . For the rest ofthe island there were 3 epidemiologists, and180 specially deputed health workers to assistthe subdivisional staff in the house-to-housesearches . In addition, 16 emergency fieldworkers worked at check-points and con-ducted municipal searches .

By 19 November, the fifth day after thediscovery of the outbreak, the first round ofvaccinations within the 12-mile radius of theinfected house had been completed . A secondround was begun, covering the same area, andwas completed 8 days later. Of a listedpopulation of 18 150, 16 295 were vacci-nated. A later assessment showed that 100%of the residents living within a half-mileradius and 95°•0 of those living within a 1 1-mile radius of the infected house had beenvaccinated .

Meanwhile, 2 consecutive house-to-housesearches within the 5-mile radius were com-pleted by 8 December. Among the 120 000population, 52 individuals with fever andrash were found, including 17 with chicken-pox and 11 with measles, but there were nocases of smallpox . During the following 2months, 2 additional house-to-house searchesof Bhola Island were conducted. During theseoperations, 2 more unreported smallpox out-breaks were discovered : one had occurred in1974 and had resulted in 18 cases and 6deaths ; the second involved 1 person, whohad become ill in July 1975 .

At the end of December, the additionalstaff who had been sent to Bhola began tobe recalled to their respective districts .Kuralia was declared smallpox-free and the2-year post-epidemic surveillance periodcommenced .

MORBIDITY AND MORTALITYDATA

To obtain precise data on the age distribu-tion and case-fatality rates for smallpox,special studies were undertaken in 1976 toenumerate all cases and deaths in 165 out-breaks, including 115 that constituted the lastoutbreaks in the country, and 46 others,which were investigated in northern BograDistrict. In all, 1127 cases were recorded(Table 16 .17) .

Cases occurred among all age groups butthe youngest were the most heavily afflicted.Of the total, 55% occurred among childrenunder 10 years of age, a group that made uponly 34% of the population. Overall, the case-fatality rate was 18%, comparable to that inIndia. The much higher case-fatality rateamong males over 20 years than among

16. BANGLADESH

females in the same age group was notable butno explanation was found for this disparity .

CONCLUSIONS

The programme in Bangladesh wasuniquely distinguished by extremes withpeaks of optimism and success alternatingwith catastrophic setbacks resulting fromnatural disasters of flood and famine andman-made disasters inflicted by civil war andthe disruptive reorganization of the healthservices . The frustration and pessimism ofthe programme staff during the spring of1975 were matched only by the feelings oftheir counterparts in Bihar State, India, 6months earlier and are vividly depicted in thebook Quest for the Killers (Goodfield, 1985) .

The successful application of a surveil-lance-containment programme in thespring of 1970 had so rapidly and so easilyinterrupted transmission that it was difficultto believe that the success could not berepeated in 1972 or in the 2 succeedingyears. In retrospect, the 1970 experience inBangladesh to some extent paralleled eventsin India, where, for example, transmissionwas so rapidly interrupted in Tamil NaduState (population, 41 million) in 1968 andin Gujarat State (population, 27 million)in 1971 . These successful programmesengendered unwarranted confidence thattransmission could be quickly interrupted ina population already reasonably well vacci-nated and with so numerous a healthstaff available. What was not appreciated wasthe dearth of supervision of the host of healthworkers in many parts of India and inBangladesh. Given optimum conditions ofpopulation stability, vigorous and enlight-ened senior programme leadership andthe application of surveillance-containment

847

Table 16.17 . Bangladesh : cases of and deaths from smallpox and case-fatality rates in 165 outbreaks, by ageand sex, 1975

Males Females TotalAge group(years) Number of Number of Case-fatality Number of Number of Case-fatality Number of Number of Case-fatality

cases deaths rate (%) cases deaths rate (%) cases deaths rate (%)

0-4 148 35 24 188 55 29 336 90 275-9 128 17 13 151 23 IS 279 40 1410-19 101 17 17 95 14 I5 196 31 16

20 154 34 22 162 14 9 316 48 I5

Total 531 103 19 596 106 18 1 127 209 18

8 4 8

measures at a declining or low point in thelong-term periodicity of smallpox, a modestsurveillance-containment programme wasrapidly and dramatically successful . Whennatural or man-made disasters created hordesof refugees, when leadership was deficient orwhen smallpox was at the height of itsperiodic wave, it became apparent that thehealth structure had little in reserve withwhich to cope with the situation .

Progress in programmes in the northernand eastern states of India had been disap-pointing and frustrating, but within littlemore than a year after the special intensifiednational programme began in September1973, transmission was interrupted . In Bang-


ladesh, however, the interruption of transmis-sion, once successfully achieved, was frus-trated in each of 3 successive years byunexpected disasters. With courageous confi-dence, bolstered by material support fromSweden and other countries, a remarkablydiverse national and international staff madeone more heroic effort in 1975 and succeededin attaining their goal . If civil war had brokenout in August 1975, following the assassi-nation of Sheik Mujibur Rahman, transmis-sion would probably have persisted for atleast another year and might perhaps still beoccurring. History records, however, thatRahima Banu was the last victim of variolamajor-on 16 October 1975.

bangladesh - louisiana state university 16.pdf · bangladesh contents introduction the last case of...

Documents