Factors associated with the recurrence of cholera outbreaks in Rumonge Health District in Southern Burundi: An unmatched case-control study

Cholera remains a public health concern in Rumonge Health District. The area is regularly affected by the disease outbreaks despite control measures that are periodically taken after the outbreaks occur. The last outbreak started in late 2018 and ended in February 2019, with a cumulative of 234 cases, and one death. This study aimed to identify the risk factors associated with the 2019 cholera outbreak in Rumonge Health District. We conducted a retrospective unmatched (1:2) case-control study to investigate risk factors associated with the 2019 cholera outbreak. This was carried out from 5 March 2021-30 April 2021 in 150 households, comprising 50 cases and 100 controls. Cholera cases were drawn from the admission register of cholera patients at Rumonge referral hospital. Stratified proportional allocation sampling followed by simple random selection were used to select the cases. Afterwards, we visited the households of the selected cases and controls that were chosen among the neighborhood of the cases. An interviewer-administered questionnaire was administered to the head of each household to collect sociodemographic, water, sanitation, and hygiene practice data. Multivariate analysis with logistic regression model was used to analyze the data. A multivariate analysis revealed that drinking lake/river water (OR=3.6 [1.46-8.87]), utilizing untreated water for domestic purposes (OR=5.2 [1.31-20.59]), consuming unwashed raw fruit (OR=2.9 [1.08-7.97]), eating without washing hands with soap (OR=3.2 [1.30-8.29]) and improper washing of hands after defecation (OR=2.7 [1.10-6.84]) were predictors of cholera outbreaks in Rumonge Health District. The study revealed that drinking lake or river water, using untreated water for domestic purposes, consuming unwashed raw fruits, eating without washing hands with soap, and improper handwashing after defecation were all strongly associated with increased risk of cholera. We recommend a community-based approach through the provision of safe water, strengthened hygiene education, and integrated WASH interventions in Rumonge Health District.