Bacillus cereus food poisoning at factory, Yogyakarta, Indonesia

Abstract

Background: On 9 January 2021, Tegalrejo Public Health Center (PHC) reported a suspected food poisoning after having lunch at a factory in Yogyakarta. Investigations were carried out to confirm the presence of an outbreak and find out the source and mode of transmission. 

Methods: Unmatched case control study with 1:2 ratio, the case was the person who consumed lunch from catering on 8 January 2021 and experienced symptoms such as diarrhea, nausea and stomachache on 8-9 January 2021. Data was collected through interviews using questionnaire and Google Form. Interviewing food handlers and observation were done for environmental investigation. Odds Ratio  value was estimated to determine food with highest risk of getting ill. Food samples were examined by BLK Yogyakarta.

Results: Of the 177 people on the list, 167 were successfully interviewed.  53 people were found ill (AR 31.7%; n=167) with diarrhea (98.1%) and stomachache (28.3%) as the main symptoms. Average incubation time was 12 hours, with a period of 4 hour – 19 hour 35 minutes. Through multivariate analysis, it is found that the suspected food is vegetable fritter (OR=2.17; p=.049; CI 95%: 1.003-4.73). Bacillus cereus bacteria was found in the vegetable fritter. Lack of hygiene in the kitchen and improper food handling and storage will facilitate the contamination and spore growth. Investigation results were reported to a few officials in the Public Health Department to avoid polemic within the community. 

Conclusion: There was a food poisoning outbreak in a factory which was caused by Bacillus cereus in vegetable fritters. Socialization regarding food processing and food safety are important to be conducted to prevent similar incidents.