Food Poisoning Amongst Census Enumerators in Gokwe South, Zimbabwe, August 20124
D Bangure1D Chirundu1, M Tshimanga1, NT Gombe1, L Takundwa1
1Zimbabwe Field Epidemiology Training Program 2Kadoma City Health
Background: Zimbabwe implemented a national census from the 18 to 28 August 2012. On 15 August 2012, a report was received of gastrointestinal illness among census enumerators during training in Gokwe. A total 729 enumerators and 180 supervisors attended this training. More than 300 enumerators fell ill. We investigated the outbreak to characterize the illness and identify the causative agent.
Methods: We conducted a retrospective cohort study. We used snowballing to identify and recruit respondents. We interviewed 117 enumerators to collect data on signs and symptoms of illness and food items consumed. Food preparation surface and rectal swabs for culture were collected. Data was analyzed using Epi InfoTM to generate frequencies, means, proportions, relative risks (RR), and attributable risks (AR), and 95% Confidence Intervals.
Results: We interviewed 117 enumerators. The median incubation period was 7 hours (Q1=6; Q3=11). Different kitchens were used for preparing supervisors’ and enumerators dishes but source of the food was the same. Common signs and symptoms included abdominal cramps – 71%, watery diarrhoea – 67%, nausea – 52%, and fever – 27%. All patients fell ill within one incubation period. Eating beef during lunch on 14/08/12 was associated with illness (RR=5.07, 95% CI=2.05 – 12.57). The AR for beef was 63%. Leftover food was not available for laboratory analysis. Staphylococcus aureus was isolated from patients, food handlers and serving table surface.
Conclusions: The illness was a food poisoning outbreak, caused by S. aureus. Beef consumed during lunch on 14/08/12 was the possible source of infection. The contamination occurred during food preparation in the kitchen used to prepare food for the enumerators. Screening of food handlers and involvement of local health department in planning mass gathering is recommended.