150

lateral sclerosis in the Mariana Islands of the SouthPacific 11 and in the discovery of a new disease of thenervous system, kuru,12 affecting natives in the easternhighlands of New Guinea.A third example of the importance of neurological

research in the tropics is the description, during the pastdecade, by CRUICKSHANK and his colleagues in theUniversity of the West Indies, of " Jamaican para-plegia ".13-1 The investigation of this puzzling chronicdisorder in Jamaican adults illustrates the many diffi-culties in the way of clinical research in local com-munities. The syndrome has five main elements arisingin different combinations: damage to the pyramidaltracts and posterior columns of the spinal cord; selectivelower-motor-neurone lesions, retrobulbar neuropathy,and nerve deafness. The condition is also found in otherCaribbean islands and has some features in commonwith the myelopathies discovered in Africa and the FarEast. The latest report 18 from Jamaica is based on ananalysis of 206 cases and 11 necropsies. There seem tobe two distinct groups: ataxic (25 cases) and spastic(181 cases). The cases that came to necropsy belongedto the spastic group. In the ataxic group there was ahigh incidence of optic atrophy and eighth-nervedeafness, with slight evidence of pyramidal-tractdamage. Patients in this group were poorly nourished.In the larger spastic group the incidence of optic atrophyand eighth-nerve deafness was relatively low. Thehistopathological findings in the spastic cases werethose of a chronic meningomyelitis, with damage to thelong tracts as the major lesion.

In Africa and the Far East these and similar syndromeshave usually been confined to malnourished people, butin Jamaica, in the spastic group, nutrition seemed to besatisfactory. Toxic elements in the diet have beenconsidered, in view of the resemblance to lathyrism andthe widespread consumption in the Caribbean of " bushteas ", some of which have been incriminated in anotherJamaican syndrome-veno-occlusive disease of theliver. But no connection has been traced between anyof the native plants and these neurological disorders.The possibility that a treponema is responsible has alsobeen closely examined. Random serum samples fromadult Jamaicans have shown positive treponemal reactionsin 20-40%. In the ataxic group the treponemal reactionsin the blood were negative in 64%; in the cerebrospinalfluid they were negative in all cases, and there was noabnormality of protein or cell content. On the otherhand, 60% of the spastic group gave positive reactionsin the blood, although in the cerebrospinal fluid they werepositive in only 6%. A moderate increase in lympho-cytes and/or protein was found in 40% of cases. TheArgyll-Robertson pupil was rare, and penicillin therapyfailed to help the patient or to influence the cerebro-11. Kurland, L. T. Proc. Mayo Clin. 1957. 32, 449.12. Gajdusek, D. C., Zigas, V. New Engl. J. Med. 1957, 257, 974.13. Cruickshank, E. K. W. Ind. med. J. 1956, 5, 147.14. Cruickshank, E. K. Fed. Proc. 1961, 20, suppl. 7, p. 345.15. Cruickshank, E. K., Montgomery, R. D. W. Ind. med. J. 1961, 10, 211.16. Cruickshank, E. K., Montgomery, R. D., Spillane, J. D. World Neurol.

1961, 2, 199.17. Robertson, W. B., Cruickshank, E. K., McMenemey, W. H., Mont-

gomery, R. D. Proc. IV Int. Congr. Neuropath. 1962; vol. III, p. 434.18. Montgomery, R. D., Cruickshank, E. K., Robertson, W. B.,

McMenemey, W. H. Brain, 1964, 87, 425.

spinal-fluid changes. Lastly, endarteritis obliterans, thecharacteristic feature of neurosyphilis, was not observed.Worldwide comparative studies will obviously be

necessary before the cause or causes of these obscuretropical myelopathies and neuropathies are unravelled.They provide a fine field of clinical research which shouldstir the imagination of young neurologists in the develop-ing nations, and they offer opportunities for inter-national liaison. The World Federation of Neurologyhas already established a Commission on TropicalNeurology, and the first international symposium washeld in Buenos Aires in 1961.19

Lathyrism has been known since the time of Hippo-CRATES. He wrote:" at Ainos those men and women whocontinually fed on pulse were attacked by a weakness inthe legs which remained permanent". There is littledoubt that he would have been equally intrigued byJamaican paraplegia.

Annotations

HEALTH OF IMMIGRANTS

OF the 300,000 people living in Bradford in 1963, about12,000 were immigrants from Asia. Of the 353 new casesof tuberculosis reported during the year, 203 were inAsians 2; in other words, 4% of the population accountedfor nearly 60% of the cases. Edgar 21 has shown thatnearly all these immigrants came from Pakistan. InBirmingham, Springett 22 found that tuberculosis wastwenty-seven times as common among Pakistani immi-grants as among the indigenous population.

Stevenson 23 estimated that 50% of the immigrants withtuberculosis in Bradford had contracted it since theirarrival in this country; and Aspin 24 put the figure as highas 80% for Indians in Wolverhampton. Their resistancemay be innately low: they are subject to the stresses of analien environment; they live in closed communities; evenwhen proper housing is available, our inhospitable climatecrowds them together in search of warmth and companion-ship. There is no evidence that the disease is spreading tothe rest of the community, but this may be due only to thevery isolation which is the greatest source of danger to theimmigrants themselves.Our chest clinics may be able to deal with the existing

and discovered cases, but unaided they cannot cope with asteady influx of undetected new infection. All the authorswe have quoted said that control was impossible unless allimmigrants had a chest X-ray on or before arrival here-an opinion that we 25 and others 26 have supported.Moreover, the British Medical Association has repeatedlyasked for compulsory X-ray examination on arrival 27 28;and Aspin 24 suggested that the examination should berepeated annually.The Ministry of Health has now announced the

following arrangements to deal with the problem.19. Proceeding of the First International Symposium of the Commission in

Tropical Neurology, World Federation of Neurology, Buenos Aires,1961. Buenos Aires, 1963.

20. Douglas, J. Annual report of the medical officer of health, Bradford,1963.

21. Edgar, W. Brit. med. J. 1964, ii, 1565.22. Springett, V. H. Lancet, 1964, i, 1091.23. Stevenson, D. K. Brit. med. J. 1962, i, 1382.24. Aspin, J. ibid. p. 1386.25. Lancet, 1962, i, 843.26. Tubercle, 1964, 45, 279.27. Brit. med. J. 1961, ii, 1624.28. ibid. 1964, ii, suppl. p. 211.

151

The chief medical officer has written to all general practi-tioners in the Health Service asking them to look out forimmigrants among their patients and to consider the need toarrange for X-ray examinations.

Immigrants who are medically examined at ports and airportswill be given a notice printed in languages they understand,encouraging them to get on the list of a family doctor withoutdelay in the district where they go to live, instead of waitinguntil they may be ill. Medical inspectors at ports and airportswill seek from these immigrants their destination addresses.These will then be sent to the medical officers of healthconcerned asking them to arrange for the immigrants to bevisited, told about the Health Service, and advised to registerwith a family doctor. As far as possible the addresses of thosenot subject to medical examination on arrival-for example, thewives and children of some Commonwealth immigrants-willalso be sent from the ports and airports to local medical officersof health to give them the same information and advice.At London Airport, where more long-stay immigrants arrive

than anywhere else, X-ray apparatus is to be installed. Whenthe medical inspectors suspect, for example, tuberculosis, theywill be able to have an X-ray taken on the spot. If this confirmstheir suspicion, they can then send information to the localmedical officer of health. (If the X-ray reveals a dangerous caseof open tuberculosis and the immigrant has not yet beenadmitted, the medical inspector may recommend to theimmigration officer to refuse entry.)Three years ago, referring to tuberculosis among

Pakistanis in Bradford, Stevenson 23 wrote: " We ... haveused every possible method to get them to the X-raymachine-by advertising at Pakistani film shows, and byhousehold canvassing, lectures, and repeated street surveyswith the mobile X-ray van in the Pakistani districts, allwithout much success." We wonder, therefore, whethercards, telling people to get themselves on a doctors list,will really be sufficient.The Governments view is that medical inspection of

intending immigrants before they leave home is impractic-able.29 Is it also impracticable to do it when they arrive ?It has been said that to examine Commonwealth immi-grants " would result in an invidious distinction beingdrawn between them and aliens who are not subjected toany such requirements ". But why should alien immigrantsnot be examined? Could not areas. where tuberculosis ishighly prevalent be so designated, as is already done withsmallpox? And why should medical examination beregarded as something obnoxious, instead of a service to ournew guests, done in their own interests ? For it is they,and their compatriots here, who are suffering.The new X-ray apparatus at London Airport will not be

used as a matter of routine, but only to examine suspiciouscases. This " should enable a clearer picture to be obtainedof the extent to which immigrants may actually be cominginto the country with tuberculosis ". But if it is to beused only when a medical inspectors suspicions arearoused, it is unlikely to prove more than that people wholook consumptive often are.London Airport receives 21/2 million people every year,

and it may well be impossible to identify those who intendto stay here and examine them on the spot; and there aremany other ports of entry to be considered. Perhapsimmigrants could be required to report to the nearestchest clinic when they reach their new home, and notsimply advised to look for a family doctor. Naturally, theGovernment is anxious to do nothing that appears todiscriminate against these new arrivals. Rightly, the aim isto treat them like anyone else, and the ultimate object mustbe to see them assimilated by the community to which

29. See Lancet, 1964, ii, 1300.

they are making a valuable contribution. But beforeaccepting them, the communities in which they live willwant to be further assured that their own health is notbeing endangered.

ANTIVIRAL AGENTS

PESSIMISM has for long prevailed about the prospects offinding effective antiviral agents, just as it did in thetwenties and early thirties about the possibility of findingeffective in-vivo antibacterial substances. But pessimism isgiving way to cautious optimism, since at least two effectiveantiviral drugs are now available commercially. The workwhich led to the discovery of antiviral substances hasbeen reviewed from the clinical standpoint by Stuart-Harris and Dickinson. There is great interest in thissubject, not only because of the prospects for the cure orprevention of virus disease but also because of the lightthat antiviral agents shed on the processes of viralsynthesis. And this interest was evident in the largeattendance at a meeting of the New York Academy ofSciences on Dec. 9-11.One of the strongest influences in the change of opinion,

about chemoprophylaxis at least, has been the work ofDr. D. J. Bauer and his colleagues on methisazone in theprevention of smallpox in those exposed to infection. Itwas appropriate therefore that a whole session at themeeting was devoted to the thiosemicarbazones; andDr. Bauer was awarded the A. Cressy Morrison prize of theNew York Academy of Sciences for his paper on clinicalexperience with methisazone. He reported the extensionof his work on contacts of smallpox treated prophylacticallywith methisazone to over 2000 in the treated and controlgroups, with essentially the same results as before.2 Thus,there were 114 cases and 20 deaths in the controls and 6cases and 2 deaths in the treated group. In a smallgroup who had no prior vaccination there were 28 casesand 11 deaths amongst 100 controls and only 2 casesamongst 102 treated contacts. Methisazone has beenshown in tissue culture (in experiments described at themeeting by G. Appleyard) to prevent the synthesis ofpox-virus proteins which appear late in the virus growthcycle. In sufficient dosage, the drug completely preventsthe synthesis of infectious virus; thus, a relatively shortperiod of treatment should suffice, and Bauer suggestedthat a period of two growth cycles was enough. Such ashort treatment period may well be important in view ofthe severe nausea and vomiting produced by methisazone,3which will discourage its use except under severe threat.Indeed, the thiosemicarbazones were abandoned asantituberculosis. drugs mainly because of their toxicity.Of the thiosemicarbazones, methisazone is not the most

active against pox viruses. It was selected for initial studybecause it was easier to make and more was known of itstoxicity. Another thiosemicarbazone (M. & B. 7714), whichAppleyard found had a mode of action similar to methisa-zone but was slightly less active against rabbit pox, wastried by J. A. McFadzean in a controlled trial for the treat-ment of smallpox. He found that there were 42 deaths in132 control cases and 24 in 131 patients treated withM. & B. 7714, a difference which was not statistically sig-nificant ; but C. H. Kempe thought that a larger seriesconfined to early cases might well prove the value of this1. Stuart-Harris, C. H., Dickinson, L. The Background to Chemotherapy

of Virus Diseases. Springfield, Ill., 1964.2. Bauer, D. J., St. Vincent, L., Kempe, C. H., Downie, A. W. Lancet,

1963, ii, 494.3. Landsman, J. B., Grist, N. R. ibid. 1964, i, 330. Hutfield, D. C., Csonka,

G. W. ibid. p. 329.