Epidemiological investigation of a cholera outbreak and its socioeconomic determinants in southwest state, Somalia, January - August, 2024.

Abstract

Introduction: Cholera remains a significant public health challenge in Somalia, particularly in the Southwest State, where recurrent outbreaks have been reported in January 2024. We investigated the epidemiological characteristics of a recent cholera outbreak in the southwest of Somalia and explored the socioeconomic determinants contributing to its persistence.

Methodology: A descriptive cross-sectional study was conducted in Southwest State, Somalia, from January to August 2024, to characterize the outbreak using time, place, and person analyses, and to evaluate the frequency and distribution of cholera cases. Data were collected through structured interviews, a review of medical records, and a line list of suspected cases and epidemiologically linked patients at cholera treatment centers. Data were analyzed using SPSS. Logistic regression was used to examine the factors associated with cholera. A p-value of less than 0.05 was considered to be statistically significant.

Results: A total of 5,639 cholera cases were recorded during the study period, with 2891 (51.3%) female. The case fatality rate was 0.5%. Among the cases, 663 (11.8%) tested positive for Vibrio cholerae 01 Inaba at the National Public Health Reference Laboratory. The outbreak predominantly affected children under five, accounting for 3203 (56.8%) of cases with a male-to-female ratio of 1.1:1 and an attack rate of 11.3 per 1,000. Watery Diarrhoea 4716 (83.6%), vomiting 4004 (71.0%), fever 5208 (92.4%), and abdominal cramps 3108 (55.1%) were the most common symptoms observed in the patients. Only 451 (11.8%) of cases reported having received the oral cholera vaccine. There were significant associations between high cholera incidence and low vaccination rate (AOR: 4.6, 95% CI: 2.63-8.49, p < 0.001) and limited access to safe drinking water (AOR: 2.4, 95% CI: 2.05-2.89, p < 0.001). Conversely, the availability of latrines (AOR: 0.5, 95% CI: 0.36-0.69, p < 0.001) and handwashing facilities with soap (AOR: 0.6, 95% CI: 0.48-0.79, p < 0.001) showed protective effects against cholera incidence.

Conclusion: The cholera outbreak in Southwest State significantly impacted children under five. Low vaccination rate and limited access to safe drinking water were strong risk factors, whereas the presence of latrines and availability of handwashing facilities with soap were protective against the outbreak. Urgent interventions are essential to enhance vaccination efforts, improve sanitation infrastructure by increasing the number and accessibility of latrines, providing adequately spaced handwashing stations with soap, water, and drying facilities in public places, and ensuring access to safe drinking water to prevent future outbreaks.