Investigation of an outbreak of food poisoning in a resource-limited setting

Abstract

An acute onset of gastrointestinal symptoms among people who had attended and eaten at a burial ceremony generated a lot of public concern as indicated by subsequent media reports. We, therefore, set out to investigate this outbreak with the aim of assessing its magnitude and identifying the implicated food item.Case patients were sought, line listed and described. A retrospective cohort design was used to evaluate the risk for each food item reported to have been served at the ceremony.Atotal of 60 case patients and 3 deaths were identified. Symptoms reported included fainting spells in 100% of patients, vomiting in 86% and diarrhea in 7%. The average incubation period of the disease was 90 minutes (range 30 to 150 minutes). The risk difference for each food item reported to have been served at the ceremony was observed to be 59.2% for meat, 52.9% for mixed yam/cassava flour “amala”, 52.9% for vegetable “ewedu”, 42.9% for rice grain and 45% for sachet water. This investigation provided the opportunity to identify the major constraints to an effective outbreak investigation in our environment, including inadequate preparedness and lack of public health laboratories; hence it is necessary for the government at all levels to support the provision of this service.

Keywords: Outbreak Investigation, Food Poisoning, Nigeria.