International Notes Outbreak of Pellagra Among Mozambican Refugees - Malawi, 1990
Micronutrient deficiency disorders, including pellagra, have emerged as major problems in refugee populations that depend on international relief assistance for food
International Notes Outbreak of Pellagra Among Mozambican Refugees - Malawi, 1990
Micronutrient deficiency disorders, including pellagra, have emerged as major problems in refugee populations that depend on international relief assistance for food supplies (1,2). This report summarizes an investigation of pellagra that occurred among Mozambican refugees in Malawi during 1990.
Since 1987, approximately 900,000 Mozambicans have fled armed conflict in their homeland to seek refuge in neighboring Malawi. Approximately half are housed in refugee camps; the remainder live in villages integrated with the local Malawian population. Overall refugee relief assistance is coordinated by the Office of the United Nations High Commissioner for Refugees (UNHCR). Health care is provided by Malawian Ministry of Health personnel assisted by private voluntary organizations. During July-October 1989, 1169 cases of pellagra were detected among Mozambican refugees settled in 11 sites (including both camps and integrated villages) in southern Malawi (1). From February 1 through October 30, 1990, 17,878 cases were reported among 285,942 refugees (attack rate (AR)=6.3%) (Figure 1).
During the 1989 outbreak, Medecins Sans Frontieres, Paris (MSF), the private voluntary organization that provided health care in the 11 sites, established a passive surveillance system in which persons with pellagra who presented to health facilities were recorded separately. (Previously, pellagra cases were reported as unspecified "nutritional disorders" according to the national disease surveillance system.) In July 1990, active case detection was instituted, and detailed information was collected on each patient (including age, sex, address, nationality, date of arrival in Malawi, duration of illness, and clinical signs).
A case of pellagra was defined as dermatitis on two different and symmetrical sites exposed to sunlight or a typical Casal's necklace (Figure 2). Of a sample of 992 case-patients reported in 1990, approximately 60% had associated stomatitis, and 19% had diarrhea. Diagnosis was confirmed at the National Institute of Agronomy in Paris by urinalysis for niacin metabolites (2-pyridone and N1-methyl nicotinamide) in four cases of clinical pellagra (3).
ARs ranged from 0.5% to 13.2% among the 11 refugee sites. The AR for children aged less than 5 years was 1.6%, and for all other age groups combined, 7.3%. Based on population estimates provided by the UNHCR, the AR for females was 7.8 times higher than that for males. ARs in camps were higher than those in integrated villages.
To identify potential risk factors for illness, MSF conducted a matched-pair case-control study from June 11 through June 23. Cases selected were the first 126 consecutive persons with pellagra at the outpatient facility of the three most affected sites. For each patient, one age-, sex-, and location-matched control was selected. Each patient and control provided information about sociodemographic characteristics, nutritional habits, and sources of food. A multivariate analysis suggested that three factors independently protected against pellagra: daily groundnut consumption (odds ratio (OR)=0.1; 95% confidence interval (CI)=0.01-0.95), home maize milling (OR=0.3; 95% CI=0.1-0.5), and garden ownership (OR=0.3; 95% CI=0.15-0.6).
For 1989 and 1990, food supply records from UNHCR, the World Food Program, and the Malawian government were used to calculate the mean daily per capita quantity of available niacin equivalents (ANE) in food distributed to refugees, based on bioavailability of 30% of the niacin in maize flour (4). Groundnut distribution had been disrupted from January through May 1989 and again from January through July 1990, with a corresponding mean daily distribution during these periods of approximately 4.0 mg ANE per person per day (Table 1) (5).
In August 1990, a groundnut supply was identified on the world market, purchased, transported to Malawi, and distributed to refugees by UNHCR; MSF; and Save the Children Fund, United Kingdom. In addition, nicotinamide was used to treat clinical cases, and vitamin B complex tablets were distributed as a preventive measure to refugees living in camps. Active surveillance of new cases is being used to quantify the impact of prevention and control measures. Reported by: P Malfait, MD, A Moren, MD, Epicentre, Paris, France; G Malenga, MD, J Stuckey, MD, Office of 