Botulism outbreak in a rural Ethiopia: a case series

Foodborne botulism, a toxin-mediated illness caused by Clostridium botulinum, is a public health emergency. Types A, B, and E C. botulinum toxins commonly cause human disease. Outbreaks are often associated with homemade and fermented foods. Botulism is rarely reported in Africa and has never been reported in Ethiopia.

In March 2015, a cluster of family members from the Wollega, Oromia region, western Ethiopia presented with a symptom constellation suggestive of probable botulism. Clinical examination, epidemiologic investigation, and subsequent laboratory work identified the cause of the outbreak to be accidental ingestion of botulinum toxin in a traditional chili condiment called "Kochi-kocha," cheese, and clarified butter. Ten out of the fourteen family members who consumed the contaminated products had botulism (attack rate 71.4%) and five died (case fatality rate of 50%). Three of the patients were hospitalized, they presented with altered mental status (n = 2), profound neck and truncal weakness (n = 3), and intact extremity strength despite hyporeflexia (n = 3). The remnant food sample showed botulinum toxin type A with mouse bioassay and C. botulinum type A with culture. Blood drawn on day three of illness from 2/3 (66%) cases was positive for botulinum toxin type-A. Additionally, one of these two cases also had C. botulinum type A cultured from a stool specimen. Two of the cases received Botulism antitoxin (BAT).

These are the first confirmed cases of botulism in Ethiopia. The disease occurred due to the consumption of commonly consumed homemade foods. Definite diagnoses of botulism cases are challenging, and detailed epidemiologic and laboratory investigations were critical to the identification of this case series. Improved awareness of botulism risk and improved food preparation and storage may prevent future illnesses. The mortality rate of botulism in resource-limited settings remains high. Countries should make a concerted effort to stockpile antitoxin as that is the easiest and quickest intervention after outbreak detection.