Epidemic of fatal encephalopathy in preschool children in Burkina Faso andconsumption of unripe ackee (Blighia sapida) fruit

Background On March 21, 1998, the Regional Health Authority of Bobo-Dioulas so, Burkina Faso, asked the Centre Muraz to investigate an unexplained outb reak of epidemic fatal encephalopathy (EFE). We aimed to identify the cause of this epidemic. Methods We identified cases retrospectively through review of hearth-servic e records and interviews of family members, village chiefs, and local heate rs. Active surveillance was started in administrative divisions within the study area in April, 1998, to identify further EFE-cases. We did a case-con trol study of households to investigate the risk from various environmental and health factors. Blood and urine samples were collected if possible and urine dicarboxylic acid concentrations measured by gas chromatography. Findings 29 cases of EFE were identified from January to May, 1998. Estimat ed age-specific attack rates (2-6 years) ranged from 31 to 847 per 100000 p opulation (p < 0.001). The most common symptoms were hypotonia, vomiting, c onvulsions, and coma. Ali children died in 2-48 h. The only factor associat ed with EFE was the presence of ackee trees (Blighia sapida) within 100 m o f households (odds ratio 5.1 [95% CI 1.8-14.7] p = 0.001). Poisoning with u nripe ackee fruits was suggested by urine concentrations of dicarboxylic ac ids four to 200 times higher in cases (n = 2) than in controls (n = 3). Conclusion Consumption of unripe ackee fruit probably caused this epidemic and may lead to a substantial number of unexplained deaths in preschool chi ldren in west Africa every year. Educational campaigns have the potential t o prevent these deaths.