Cholera outbreak in Andoni Local Government Area, Rivers State, Nigeria; January 2015: the role of hand washing with soap

Abstract

Background: In January 2015, an outbreak of cholera occurred in Andoni, Rivers State. We investigated to identify risk factors for infection and institute control measures.

Methods: An un-matched case-control study with 62 cases and 62 neighborhood controls was conducted. A case was defined as an individual aged 5 years or more with three or more episodes of loose watery stool with or without vomiting residing in Andoni from 11th-18th January 2015. A control was a person without history of loose watery stool and vomiting, but residing in Andoni. A Semi-structured questionnaire was used to collect data on demographic characteristics, clinical information and risk factors. Univariate, bivariate and multivariate analysis was performed using Epi-info version 7. Twenty-one stool samples and 6 water samples from open wells and ponds were analyzed.

Result: Median ages for cases and controls were 8.5 (range; 2– 65) and 18 (2–70) years respectively. Females were 32(51.6%) of cases and 36 (56.5%) of controls. The cases and controls did not differ in age and sex. Cases were less likely than controls to wash hands with soap after using the toilet (OR:0.4, Cl:0.17–0.96) and to drink from tap water (OR:0.09, 95% CI:0.01–0.69). Hand washing with soap and water remained protective of the disease after controlling for potential confounders. Eleven (52.4%) of the clinical samples and 6 (100%) of the water samples yielded vibrio cholera non O₁/O₁₃₉.

Conclusion: Unhygienic hand washing practices was identified as a risk factor for cholera infection. The source of the outbreak possibly resulted from contaminated wells and ponds. We provided community health education on personal hygiene, with emphasis on hand washing with soap, and recommended super chlorination of wells.