Abstract:
Background: Uganda targets cholera elimination by 2030, yet outbreaks persist in high-risk
fishing communities. Namayingo District in eastern Uganda has experienced recurrent
outbreaks. This study assessed factors associated with the 2023 cholera outbreak in Namayingo
to inform targeted and sustainable control measures.
Methods: A case-control study was conducted on Sigulu and Bukana Islands. Due to
incomplete matching data, the study was analyzed as an unmatched case-control design with a
1:3 case-to-control ratio. Suspected cases were persons aged ≥2 years with acute watery
diarrhea and severe dehydration or cholera-related death; confirmed cases had Vibrio cholerae
O1 or O139 identified by culture or PCR. Controls were residents with cholera-like symptoms
who tested negative. Data were obtained from standardized case investigation forms and
outbreak-response documents from the District Health Team and Ministry of Health. Bivariate
analysis used Fisher’s exact tests, and multivariable analysis applied Firth logistic regression
to address small sample bias and quasi-complete separation. Analysis was conducted using R
(2024.12.1+563).
Results: Seventeen cholera cases (6 confirmed, 11 suspected) were identified, with no deaths.
The mean age was 20 years (SD 16.9), and 77% were female. The overall attack rate was 11
per 100,000, with 82.4% of cases clustered in Secho Village on Sigulu Island (localized attack
rate: 74 per 100,000). Occupation, residence, and water treatment were significantly associated
with infection. Students had higher odds of cholera compared to fisherfolk (aOR = 8.4; 95%
CI: 2.1–33.7). Living in Sigulu increased infection odds (aOR = 6.4; 95% CI: 1.5–37.7).
Treating drinking water reduced the odds of cholera (aOR = 0.17; 95% CI: 0.05–0.55).
Conclusion: The outbreak was driven by geographic clustering, student vulnerability, and
inadequate drinking-water treatment. Strengthening safe-water access, promoting household
water treatment, and targeted health education are essential for preventing future outbreaks and
achieving cholera elimination.
