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

Abstract

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.