tumours in Namibia have an incidence in excess of the ratesusually reported in the literature_ AB and malignant bonetumours appear to be the tumour groups with the highestincidence rates in relation to other countries while leukaemiasand lymphomas constitute the main underdiagnosed cancersand also to a lesser extent, brain tumours. No reason wasfound for this possible selective underdiagnosis. Pre-emptivedeaths in the leukaemic age group and similarity ofsymptoms in leukaemias, lymphomas and infectious diseasespossibly contribute to underascertainment in these tumourgroups. No reason could be found for the high incidence ofAB and malignant bone tumours. These tumours werediagnosed mainly in children from the rural areas so thatproximity to medical facilities did not account for theincreased ascertainment of AB or bone tumours relative toother tumour groups. This high frequency of AB and bonetumours needs to be confirmed by ongoing tumourregistration. The incidence of renal tumours in Namibia andother African countries does not vary significantly from therates recorded in the majority of Western countries.

The pattern of childhood cancer in Namibia correspondsto that of industrialised countries for some diseasecategories, but demonstrates both similarities to andmarked differences from previous reports on childhoodcancer from countries in Africa.

We thank the Harry Crossley Foundation and the CancerAssociation of Namibia.

REFERENCES

1. Parkin OM. Stiller CA. Draper GJ. Bleber CA, Terracini B. Young JL eds.Inreffllfionallncidence of Childhood Cancer (IARC Scientific Publication No. 87).Lyon: International Agency for Research on Cancer. 1988.

2. Skinner MEG. 8ulawayo cancer registry. 1963 - 1977. In: Parkin OM. Stlller CA.Draper GJ. Bieber CA. Terrac,m B. Young JL. eds. Inrernarional Incidence ofChildhood Canc., (IARC Scientific Publication No. 87). Lyon: InternationalAg&ncy for Research on Cancer. 1988: 67-71.

3. Junaid TA. 5abaJoIa 80_ lbatllltl clltlcer registry. 1SEO - 198~_ In; Parkin OM.Stlller CA. Draper GJ. Sl~er CA. Terrae,", B. Young JL eds. ImemaflonaJInCIdence of Cnildhood Cancer (IARC Sc,entlfic Publication No: 87). Lyon:International Agency for Research on Cancer. 1988: 37·41.

4. Owor R. Kampala cancer regIstry, 1968 - 1982. In: ParkIn OM. Stiller CA. DraperGJ. 8ieber CA, Terraclni B. Young JL. eds. International InCidence of ChildhoodCancer (IARC Scientific Publication No. 87). Lyon: International Agency forResearch on ClltIcer. 1988: 57-61.

5. World Health Organisalion. International Classification of Diseases for Oncology.Geneva: WHO, 1976.

6 BIrch JM, Marsden HB. A cla5slfic;ation scheme for chlldhooo cancer. lne JCancer 1957; 40: 820-62~.

7. Hesselll'lg P8. Wessels G. Van Riet FA. The Tygerberg HospItal children's tumourreg,stry 1983 - 1993. £Ut J Cancer 1995: 31(9}: 1~71-1 ;;75

8. Directorale; Development Co-ol"dination_ Popularion Census for South WestAfrica m /981 (Repon 01-01 Geograph,cal Distribution). Pretoria: Directorate.Development Co·ordlnalion. 1981.

9. 8arker DJP ed. Practical Epidemiology. 2nd ed. London: Churchill Livlngstone.1976.

10. Waterhouse J. MUIr CS. Shanmugaratnam K. PowelJ J. eds. Cancer Inc.dence inFwe Continents. Vol. IV (lAMe Sc,entific Publication No 42). Lyon: InternationalAgency for Research 0t1 Cancer. 1982.

11. Young JL Ries LG. Silvertlerg E. Horm JW. MIIIel'" RW. Cancer mcicence, sut'livaland mOrtality for chileren younger Ihan age 15 years_ Cancer 1986: 58: 598..£02.

12. Birch JM. Manche5ter childr&n's lumour registry 1954 - 1970 and 1971 - 1983. In:Parkm OM. Sillier CA, Draper GJ. Bleber CA. Terracini 8. Young JL. edsIntern/irional InCidence of Childhood Cancer (IARC SCientific Publication No. 87).Lyon: International Agency for Research on Cancer, 1988.

13 Parkin OM. International data collection and interpretation: a review. Leull Res1985: 9: 661-668.

14. Parldn OM. Sillier CA. Draper GJ. 8ieber CA. The internl1JonallnCldence ofchildhood cancer Int J Cancer 1988; 42: 511·520.

15_ Plesko I, Somogyl J. Oiml1rova E. Kramatova E. DescnptlVe epidemIOlogy ofchJIchooc malignanCies in $loYalua. Neoplasma 1989: 36: 233-2~.

16. Auslln OF. Rannery J. Greenberg R. er al. The SEER Program. 1973·1982. In:Panun OM. Stiller CA. [l,.-aper GJ. 8ieber CA. Terracini a. Young JL eas.Inrernariana/ InCIdence of Childhood Cancer (!ARC Sc,entlfic PublicatIon No. 87).Lyon: Internalional Agency for Research on Cancer. 1988: 101-107.

17. M,ller RW_ No neuroblastoma in Zaire. Lancet 1989; 2: 978·979.18. M,ller RW. Rarily of neuroblastoma In East Africa. Lancet 1990; 335: 659-660.

Accepled 26 Feb 1997.

SAMJArtic es

Illicit intravenous drug usein Johannesburg ­medical complications andprevalence of HIV infectionP G Williams, S M Ansell, F J Milne

Objective. To describe the magnitude of the problem ofabuse by self-injection of dipianone HCI/cyclizine Hel(Wellconal) and to document the associated morbidity,mortality and prevalence of HIV infection.

Design. We conducted a retrospective analysis of 121admissions of 86 patients who were current intravenousWellconal abusers and presented to Johannesburg andJ G Strijdom Hospitals over an 18-month period_ Case

records were analysed in respect of age, sex, medianhospital stay, complications, HIV antibody status andeventual outcome.

Main outcome measures. Age, sex, median hospital stay,complications, HIV antibody status and eventual outcome.

Results. Complications of Wellconal abuse occurred inyoung adults (median age 24 years) with an approximatelyequal gender distribution. Opiate overdose was the mostfrequent presenting diagnosis (32%), followed by right­sided endocarditis (20%) and deep-vein thrombosis (12%).A wide variety of complications accounted for theremaining 36%. A 2% HIV antibody positivity rate wasfound, which is substantially lower than that encounteredin intravenous drug abusers in other parts of the world.Seventy-eight per cent of patients completed therapysuccessfUlly, but 19% left hospital prematurely againstmedical advice. There was a mortality rate of 3%.

Conclusions. While the prevalence of Wellconal abuse inthe broader South African community is unknown, ourstudy draws attention to the extent of the problem inJohannesburg.

S Afr Med J 1997; 87: 889-891.

Illicit intravenous self-injection of proprietary drugs and othersubstances is a common problem worldwide. In the USAthere are an estimated 1.1 - 1.8 million illicit drug injectors.1

A recent review documented the changing patterns of abuseand complications in the USA.2 Levels of HIV seropositiVityexceeding 30 - 40% and the attendant increased mortalityrate are also well shown.3ot Local patterns of abuse,complications and HIV seropositivity,s which appear to differ

Department of Medicine, University of the Witwatersrand.Johannesburg

P G Williams. MB BCh. OTWH FCP (SAl

S M Ansell. MS OlB. Q1M&ZoI. PhD

F J Milne MO. Fa' (SA)

SAMJ VolunIe 87 No. 7 luly 1997

Table I. Other complications of intravenous drug abuse

Other infective complications

Remote complications

Other complications (Table I)

(5%)

(2%)

(1%)

(1%)

(1%)

(1%)

(1%)

62

1

1

1

1

1

Infective and thrombotic complications accounted for thesecond- and third-largest groups of patients, respectively.Twenty-tour of 121 admissions (20%) were for tricuspidvalve endocarditis documented by transthoracicechocardiography with positive blood cultures in 21 patients(88%). There were no cases of left-sided endocarditis.Methicillin-sensitive Staphylococcus aureus was isolated in18 patients (86%) with valvular vegetation. One cultureyielded methicillin-resistant S. aureus in a patient who hadrecently been hospitalised; it may therefore have beennosocomially acquired. Two of the isolates yielded penicillin­sensitive streptococci. Three patients with valvularvegetation were culture-negative.

Deep-vein thrombosis occurred in 15 of 121 admissions(12%), and was invariably associated with repeated femoralvein venepuncture. Pulmonary embolism was subsequentlydocumented by isotope perlusion scan in 2 patients (2%).

The HIV status was determined in 72 of 86 patients (84%).Seventy were found to be negative by enzyme-linkedimmunosorbent assay. In 2 cases (2%) an initial screenpositivity was confirmed by Western blot assay. Fourteenpatients were not tested.

Rhabdomyolysis

Digital gangrene

5eizures

Haematuria

Anterior spinal artery syndrome

Cerebrovascular accident

Drug nephritis

Three patients presented with bacteraemia and blood culturespositive for methicillin-sensitive S. aureus. The source ofinfection was presumed to be infected venepuncture site in allthree instances. Cellulitis at venepuncture site withoutpositive blood cutture was found in 9 patients (7%).Pneumonia was diagnosed on admission in 5 patients andpelvic inflammatory disease was present in 3 patients.

Various other complications occurred that were directlyattributable to intravenous drug injection. The most frequentof these was rhabdomyolysis, which occurred in 6 patients.Arterial embolism was suspected to be the cause of digitalgangrene in 2 patients and cerebral infarction in 1 patient.One patient developed an anterior spinal artery syndromefollowing a period of hypotension as a result of accidentaloverdosage of WeJlconal.

HIV status

from those seen in the USA, Europe and south-east Asia,prompted this study.

MethodsWe conducted a retrospective analysis of patients presentingto Johannesburg and JG Strijdom hospitals over an 18-monthperiod from July 1991 to December 1992. The patient registerof the medical admissions ward was screened for one ormore of the following diagnostic categories: drug overdose orabuse, drug withdrawal, bacteraemia, endocarditis, pyrexialillness, deep venous thrombosis, pulmonary embolism andpneumothorax. All medical histories documenting currentillicit intravenous drug use leading to admission wereanalysed with regard to presenting diagnosis, age, sex,complications, type of drug used, infecting organism, HIVserology and eventual outcome. We included only patients inwhom illicit use was predominantly intravenous. Case recordswere scrutinised and blood results obtained from the SouthAfrican Institute for Medical Research. We defined drug abuseas 'illicit use of a drug on a frequent baSis'. Withdrawal wasrecorded if a patient experienced or reported dysphoria ordrug craving or had physical signs of drug withdrawal.including tachycardia, labile blood pressure, diaphoresis,mood lability or irritability. Bacteraemia was defined asisolation of an organism of known pathogenicity by Bactecblood culture technique. A diagnosis of endocarditis wasrecorded in patients who had evidence of valvular vegetationon transthoracic echocardiography. All cases of suspecteddeep-vein thrombosis were confirmed with Dopplersonography and by-venography where indicated. Cases ofsuspected pulmonary embolism underwent isotope ventilationperlusion scanning. All patients presenting with possiblepneumothorax underwent standard chest radiography.

ResultsOver the period July 1991 - December 1992 there were 121admissions involving 86 patients as a direct consequence ofillicit intravenous drug use. The only drug abused wasWellconal (dipipanone HCI and cyclizine HCI); 1 patientoccasionally used heroin as well. Men comprised 46 (53%)and women 40 (47%) of the 86 patients. The median agewas 24 years, with a range of 18 - 46 years. The mediannumber of days in hospital was 6, with a range of 1 - 67; 82of the 86 patients were Caucasian (95%), 2 men wereIndian. and 2 women were of mixed race.

Immediate complicationsWe defined these as compliCations that occurred acutely asa direct consequence of intravenous drug abuse. Opiateoverdose was the commonest consequence, responsible for39 of 121 admissions (32%). In most instances thisappeared to be accidental and without suicidal intent.Opiate withdrawal, on the other hand. was responsible foronly 6 admissions (5%). Traumatic pneumothorax occurredin 4 cases (3%) and in 2 instances was bilateral. Allpneumothoraces resulted from attempted subclavian veinpuncture and in all 4 instances required intercostal drainage.

Volume 87 No. 7 July 1997 SAMJ

SAMJArt c I e 5

OutcomeIn 94 instances the patients were fUlly treated and formallydischarged, but 23 patients (19%) left hospital againstmedical advice before completion of therapy. Four patientsdied (3%). Acute renal failure associated with rhabdomyolysiswas the cause of death in 2 patients; bacterial endocarditisand S. aureus septicaemia both accounted for 1 death each.

DiscussionWellconaJ is an opioid analgesic used in patients withterminal iIlness.s It is not licensed for use in the USA. Abuseby intravenous injection has been reported in the UK.7 Itappears that in Johannesburg, WellconaJ is the favouredintravenous drug of abuse in patients requiring hospitaladmission. Our study also serves to highlight some of thedifferences between the local population of addicts andthose encountered abroad. In Johannesburg, the majorintravenous drug of abuse is Wetlconal, and only 1 patientadmitted to concomitant use of heroin. This is in contrast tothe American experience, where addicts are seldom drugpurist, I abusing drugs from both the opiate and non-opiateclasses. This difference is probably the result of easy accessto Wellconal locally, as well as the apparent low cost of thedrug. Interviews with patients yielded a remarkably uniform'street price' of R20 per tablet (the tablets are dissolved intap water and then injected intravenously). It is clear that ifmeasures are to be taken to combat this illicit use, furtherstudies of the sources and routes of supply are needed.

A further significant difference in the local population isthe low prevalence of HIV seropositivity. Our stUdy detectedonly 2 HIV-positive patients out of a total of 72 tested. Thisis in stark contrast to the prevalence of 30 - 40% in NorthAmerica, Europe and south-east Asia. 3 In these regions,intravenous substance abuse occurs in a setting ofcommunal needle and syringe usage. with early transmissionof hepatitis and HIV.2 From personal interviews with localusers this appears not to be the case in Johannesburg, Drugusage appears to occur in a communal setting with noapparent sharing of equipment. This aspect of the local drugsubculture may explain the low HIV seropositivity and maypoint to possible avenues of ensuring the continued lowprevalence of the virus by means of risk reductionprogrammes, e.g. needle and syringe exchanges. Suchprogrammes have been shown to decrease hepatitis Btransmission in Amsterdam and the USA and there is alsosome evidence for decreased HIV transmission.! Thus thelow prevalence of HIV seropositiVity appears not to haveincreased substantially in this group of at-risk patients,despite an earlier report.sWhile fears of rapid spread inthese patient~ appear not to have materialised, this maychange.

Organisms were isolated in 21 of the 24 patients who hadechocardiographically detectable valvular vegetation: in 18cases it was methicillin-sensitive S. aureus. We found nopatients with Gram-negative, anaerobic or fungal organisms.Our study highlights the favourable response to medicaltherapy in patients with right-sided endocarditis. This alsoserves to affirm the role of therapy with penicillinase-resistantpenicillin.9 The single patient infected with methicillin-resistant

S. aureus may have acquired the infection nosocomiaJly_Deep-vein thrombosis is a frequent complication of repeatedfemoral venepuncture, the route favoured by most addicts.More frequent was pulmonary sepsis occurring secondary toembolic spread from infected injection sites. as suggested bymultifocal discrete areas of consolidation on chestradiograph, Compliance with inpatient therapy may beenhanced by prevention of opiate withdrawal symptoms byensuring that adequate doses of the opiate agonist,methadone. are administered. Consideration should be givento limiting therapy to 2 weeks of combination therapy, whichhas been shown to be effective.9

Rhabdomyolysis was documented in 6 patients and wasassociated with a less favourable outcome (mortality rate of33%) because it caused acute renal failure requiring dialysis.Rhabdomyolysis complicating illicit drug use is welldocumente(j.2 It had initially been attributed to a 'crushsyndrome' caused by comatose patients lying immobile forprolonged periods of time with consequent muscleischaemia.·~Subsequent reports have documentedrhabdomyolysis that was not attributable to localised muscleinjury but rather to a diffuse muscle injury occurring as adirect consequence of substance abuse via a number ofroutes of administration.",12 As yet unidentified adulterantscausing a toxic myositis are a postUlated cause. ll In ourseries, the high mortality rate among patients whodeveloped acute renal failure may possibly be related to thedegree of rhabdomyolysis and the attendant seriousmetabolic abnormalrties.

We have highlighted the problem of Wellconal abuse with astudy of those patients who seek medical attention for acuteillness. Despite the generally pessimistic attitude of hospitalcaregivers toward these patients, they have a good prognosisin respect of presenting illness and favourable responses tomedical therapy, as well as a low prevalence of HIVseropositivity. Given the uniqueness of the local population,conventional wisdom gained from studies of overseaspatients may not apply. Further studies are needed to definethe full extent of the problem in the broader community.

REFERENCES

1_ Selwyn PA. Illicit drug use revisited: What a long strange trip it's been (Ed'torial).Ann Intern Med 1993; 119: 1044-1045.

2. Cherubln CE, Silplra JO. The med,cal complications 01 drug addiction and Ihemedical $nessmer'll of the intravenous dru9 user: 2S years laler. Ann Intern Med1993; 119: 1017-1028.

3_ Des Jatlals DC, Friedman SR, Choopanga K, Vamchsenit S, Ward TP.Internat,onal epidemiology of HIV and AIDS among Injecting drug UseA. AIDS1992; 6: 1053-1068.

4. Selwyn PA, A1cabe p. Harte] O. er at. Clinical mamfestalions and predictors 01human Immunodefic,ency v,rus infection. N Engl J Med 1992; 327; 1697-1703.

S. De M,randa OS. Sher R. Mea J, SlfrlS 0, Lyons SF, Sehoub 80. Lack 01 eVidenceof HIV ,nlectJons In drug abusers at present (Lener). S Air Med J 1986; 70: 776­777.

6. Dundee JW, CanWiey W. Drugs lor anaesthesul. In: Speigilt TM. 00. Avery's DrugTrearment. Pnnciples and Practice of Clm/UI Pnarmacology and Therapeutics_3rd !!d. Auc and: Adis Press. 1987.

7_ B,shop BP. Cave GC. Gay MJ, Morgan HG. A crty looks at rts problems 01 drugabuse oy injeCtIOn Br J Psycniatry 1976; 129: 465-471.

8. Martin DJ, $choub BD. Entry of HIV InfectIOn Into the Intravenous drug abusmgpopulatJon (Letter). S Air Med J 1989; 75: ~9.

9 Chambers HF. MIller AT. Newman MO. Right sided staphylococcus aureusendocardllls in ,ntravenous drug abusers: two-week combination therapy. AnnInrem Med 1988; HI9,619-624.

10. Schrl!<bner SN. le'DOwitz MA. BffnSlelll LH, Srimvasan K. Limb compression andrenal ,mpa,rment (crush syndrome) compiJcat,ng narcotic oVl!fdose. N Engl J Med1971; 284: 368-369.

11. Krige LP, M,lne FJ, BayHss CB. Ahabdomyotysis and renal failure ~ unusualcomphcat,ons of drug abuse. S Afr Med J 1983; 84; 253-254.

12. Grossmiln RA, Hamilton MO, Mors!! MO, Penn AS, Goldberg M. Non traumaticrhabdomyolys,s and acute renal failure. N Engl J Med 1974; 291; 807-811.

Accepted 28 Jan 1997.

SAMJ \'oll.lmt Si No. 7 July 1997