Cholera outbreak in a rural south - south Nigerian community: a case-control study

Abstract

Background: Cholera remains a disease of public health importance in Nigeria associated with high morbidity and
mortality. On the 4th of June 2024, the Nigeria center for disease and control prevention (NCDC) through the Disease
Surveillance and Notification Officer (DSNO) reported an increase in the number of reported cases of vomiting and
diarrhea in Toru-Orua village, Sagbama Local Government Area Council, Bayelsa State, Nigeria. A team of researchers
was deployed to investigate the outbreak with the objectives of verifying the diagnosis, identifying risk factors and
instituting appropriate control measures to control the outbreak.
Methodology: We conducted a case-control study. We defined a cholera case as any person aged ≥5 years with acute
watery diarrhea in Toru - Orua community. We identified community controls. A total of 93 cases and 118 controls were
recruited. Structured questionnaires were administered to both cases and controls. Four stool samples from case-patients
and two water samples from the community water source were collected for laboratory investigation. We performed
univariate and bivariate analysis using Epi-Info version
Results: The mean age of cases and controls was 20.3 years and 25.4 respectively (p value 0.09). Females constituted
50% (cases) and 60% (controls). The attack rate was 4.3% with a case fatality rate of 13%. Four stool (100%) specimen
tested positive for Vibrio cholerae. The water source and environment were polluted by indiscriminate defecation.
Compared to controls, cases were more likely to have drunk from the river forcados (OR 14.2, 95% CI: 5.5–36.8) and
living in households (HH) with more than 5 persons/HH (OR 5.9, 95% CI: 1.3–27.2). Good hand hygiene was found to
be protective (OR 0.3, 95% CI: 0.1–0.7).
Conclusion: Vibrio cholerae was the cause of the outbreak in Toru - Orua. Drinking water from river forcados, living in
overcrowded HH and poor hand hygiene were significantly associated with the outbreak. We initiated hand hygiene and
water treatment to control the outbreak.