Retrospective Study of an Epidemic Vibrio Cholerae in the Central Region of Ghana; An Evidence from Surveillance Data

Abstract

Background: In the Central region of Ghana, cases of cholera were detected in October 2016, in the Cape Coast Metropolis. The number of cases detected in the peri-urban communities rose exponentially indicating a high transmission potential of infections. We conducted a descriptive analysis of surveillance data of the 2016 cholera outbreak in the Central Region with the aim of describing the epidemiological features of the outbreak. Methods: A retrospective analysis of cholera cases between October and December 2016 was conducted using variables including date of onset of symptoms, age, sex, rapid diagnostic test (RDT) results and district of residence of cases. Cases were descriptively characterized in terms of time, place, and person, attack rates were computed, and an epidemic curve was constructed using the date of onset of symptoms of cases.Pearson chi-square/Fisher exact tests were used to determine associations among selected variables of cases. Results: A total of 731 cases of cholera were reported with an overall attack rate of 67 cases per 100,000 population; no fatalities were recorded. The epi-curve showed multiple progressive peaks denoting a propagated type of outbreak driven by person-to-person transmission of infections. The mean age was 23 years, with 40% of cases occurring in the age group 15-24 years. The difference between the number of cases for males and females was not significant (p-value = 0.619). Close to 90% of all cases were reported from the Cape Coast Metropolis. Abura-Asebu-Kwamankese (AAK) and Komenda-Edina-Eguafo Abirem (KEEA) had a combined number of 64 cases (10%). There was a significant association between RDT results and the bacterial culture test (p<0.001), as well as that between sex and final case classification (p=0.004). Conclusion: The cholera outbreak affected a total of 731 people, with the highest number of cases reported in the 15-24 year age group. The outbreak was driven by person-to-person transmission and contaminated food and water sources. Rampant open defecation, open roadside food and water vending, and poor personal hygiene practices including hand washing were identified as major risk factors. The Cape Coast Metropolis and the KEEA were the most affected with the highest number of cases and the highest attack rate. The outbreak was predominantly confirmed through rapid diagnostic tests and culture confirmation. Current and future development projects must be geared towards effective town planning and decongestion, provision of designated dumping sites, toilet facilities and more water treatment plants. It is also imperative that district health officials also explore the issues of poor health-seeking behavior and access to care as possible factors contributing to high morbidities. Keywords; Cholera, Cape Coast Metropolis, Attack rate, Retrospective analysis