Epidemic cholera among refugees in Malawi, Africa: treatment and transmission.

Between 23 August and 15 December 1990 an epidemic of cholera affected Mozambican refugees in Malawi causing 1931 cases (attack rate = 2.4%); 86% of patients had arrived in Malawi < 3 months before illness onset. There were 68 deaths (case-fatality rate = 3.5%); most deaths (63%) occurred within 24 h of hospital admission which may have indicated delayed presentation to health facilities and inadequate early rehydration. Mortality was higher in children < 4 years old and febrile deaths may have been associated with prolonged i.v. use. Significant risk factors for illness (P < 0.05) in two case-control studies included drinking river water (odds ratio [OR] = 3.0); placing hands into stored household drinking water (OR = 6.0); and among those without adequate firewood to reheat food, eating leftover cooked peas (OR = 8.0). Toxigenic V. cholerae O1, serotype Inaba, was isolated from patients and stored household water. The rapidity with which newly arrived refugees became infected precluded effective use of a cholera vaccine to prevent cases unless vaccination had occurred immediately upon camp arrival. Improved access to treatment and care of paediatric patients, and increased use of oral rehydration therapy, could decrease mortality. Preventing future cholera outbreaks in Africa will depend on interrupting both waterborne and foodborne transmission of this pathogen.

PIP: An epidemiologic investigation of a 1990 cholera outbreak among Mozambican refugees in the Nyamithuthu camp in Malawi highlighted the challenges of providing adequate treatment and prevention in this setting. Between August 23 and December 15, 1990, 1931 cholera patients were admitted to the camp's intravenous (IV) treatment tent (attack rate, 2.4%); 28% were under 6 years of age. There were 68 deaths among these patients, for a case-fatality rate of 3.5%. 84% of patients for whom data were available had come to Malawi less than 3 months before the onset of illness and 52% were admitted for treatment within 16 days of camp arrival. 60% of the 40 cholera deaths investigated in detail involved children under 4 years of age (17% of total cases). Acute dehydration was the most common cause of death among the 63% who died within 24 hours of IV tent admission, suggesting delayed presentation and inadequate early rehydration. The remaining patients died from complications (e.g., infections with fever caused by prolonged IV use). In 2 case-control studies, cholera was significantly associated with placing hands into the storage container holding household drinking water (odds ratio, 6.0), obtaining drinking water from the river (odds ratio, 3.0), and eating leftover unheated cooked peas (odds ratio, 8.0). Toxigenic Vibrio cholerae O1, serotype Inaba, was isolated from patients and stored household water. Increased water rations and running water during cholera outbreaks are recommended to reduce contamination of stored drinking water during washing. More rapid referral to IV tents, administration of oral rehydration solution in addition to IV, quick removal or replacement of IV lines to prevent infection, and more attention to child cases also would reduce cholera mortality.

STD rapid assessment in Rwandan refugee camps in Tanzania.

OBJECTIVE: To obtain baseline information on sexually transmitted diseases (STDs) in the Rwandan refugees camps in Tanzania, prior to establishment of STD services. SETTING: The largest camps of Rwandan refugees in the Ngara District of Tanzania (estimated population 300,000). The study was carried out in 8 days in August 1994. SUBJECTS AND METHODS: A rapid assessment technique was used to measure STD prevalences among: (i) 100 antenatal clinic attenders (ANC); (ii) 239 men from outpatient clinics (OPD); and (iii) 289 men from the community. Interviews (by questionnaire) and genital examination were performed for all participants; sampling for females included genital swabs for the the diagnosis of Neisseria gonorrhoeae (NG), Candida albicans (CA), Trichomonas vaginalis (TV), bacterial vaginosis (BV) and a blood sample for syphilis serology. Men provided urine samples which were screened for leucocytes using the leucocyte esterase (LE) dipstick; urethral swabs for Gram stain were taken from men with a reactive LE test and from those with symptoms or signs of urethritis. OPD males provided a blood sample for syphilis serology. RESULTS: All groups reported frequent experience with STDs and engaging in risky sexual behaviour prior to the survey. During the establishment of the camps, sexual activity was reportedly low. Over 50% of ANC attenders were infected with agents causing vaginitis (TV/BV/CA) and 3% were infected with NG. The prevalence of active syphilis was 4%. In the male outpatients, the prevalence of urethritis was 2.6% and of serological syphilis was 6.1%. Among males in the community, the prevalence of urethritis was 2.9% (the majority being asymptomatic infections). We noted frequent over-reporting of STD symptoms, unconfirmed clinically or biologically. CONCLUSIONS: STD case detection and management should be improved by training health workers in using the WHO syndromic approach, and through IEC campaigns encouraging attendance at clinics. Rapid epidemiological methods provide quick and useful information at low cost in refugee camps.

An outbreak of pellagra related to changes in dietary niacin among Mozambican refugees in Malawi.

Between February and October 1990, 18,276 cases of pellagra dermatitis (due to niacin deficiency) were reported among 285,942 Mozambican refugees in Malawi. Overall, 6.3% of the refugee population developed pellagra and the attack rate was 7.8 times higher among women than men. This outbreak followed a 5-month cessation of groundnut distribution (the major source of niacin) to refugees. A matched-pair case-control study confirmed the protective role of the daily consumption of groundnuts (Odds Ratio [OR] = 0.08), as well as the independent role of garden ownership (OR = 0.34), and home maize milling (OR = 0.3). Recommended corrective action included early case finding and treatment, distribution of niacin tablets, prompt identification of groundnut supply on the world market, fortification with niacin of the food ration and diversification of the food basket through access to local markets.

PIP: Between February and October 1990, health workers in Malawi noted 18,276 cases of pellagra among 285,942 Mozambican refugees. This represented a significant increase in pellagra cases (compared with just 1169 cases in 1989). 5 months before each outbreak, the UN High Commission for Refugees and the World Food Program could not obtain groundnuts, a source of niacin, to include in food rations. The food ration distributed to refugees had an average of just 4 mg available niacin equivalent (or 2 mg/1000 kcal) which was considerably less than the recommended daily allowance of 6.6 mg/1000 kcal. The overall attack rate stood at 6.4% (4.9-13.2%. It was higher among refugees living in camps than it was among those living in Malawian villages near the border (10.1% vs. 0.8%). The attack rate was 7.8 times higher in females than males (6.1/1000 vs. 0.78/1000). It was lowest among children under 5 years old (1.7% vs. 7.5% for = or 5 year olds). No infant had pellagra. Researchers compared 126 pellagra cases with 126 controls. The conditional logistic regression indicated that pellagra cases were less likely to eat groundnuts and fish at least once a day within the last 6 months (odds ratio [OR] = .07 and .56, respectively). They tended not to have a garden (OR = .32) and to mill maize at home (OR = .26). Thus, eating groundnuts, milling maize at home, and garden ownership protected the refugees from developing pellagra. In August 1990, relief workers distributed niacin tablets to refugees. The health workers recommended other corrective actions such as early case finding and treatment, identification of groundnut supply on the world market, and diversification of the food basket through access to local markets.