Observational study links shared toilets and persistent fever to typhoid in Nairobi

The adjusted analysis identified persistent fever, shared flush-toilet use, moderate dehydration, vomiting, headache, older age and having two or more children under five in the household as factors associated with culture-confirmed typhoid. The study, which enrolled patients at seven health facilities between November 2020 and July 2025, reports these results as associations rather than proof that any one factor caused infection. Researchers enrolled patients presenting with a temperature of at least 38 degrees Celsius and/or diarrhoea.

They collected sociodemographic, environmental and clinical information through structured questionnaires and case report forms, and performed blood and stool cultures to test for S. Typhi. Potential risk factors were assessed with chi-square tests and multivariable logistic regression, which estimated adjusted odds ratios with 95% confidence intervals.

Of the full group, 131 patients had positive blood cultures, with a 95% confidence interval of 1.23% to 1.73% for the observed positivity. Continuous fever, defined as a temperature of at least 38 degrees Celsius for the preceding three days, had the largest reported clinical association. These patients had 3.48 times the adjusted odds of typhoid infection, with a 95% confidence interval of 2.11 to 5.73.

Moderate dehydration was associated with 2.95 times the adjusted odds, with a 95% confidence interval of 1.25 to 6.95. Vomiting was associated with 1.89 times the adjusted odds, with a 95% confidence interval of 1.29 to 2.75, while headache was associated with 1.68 times the adjusted odds, with a 95% confidence interval of 1.12 to 2.53. These symptom patterns were independently associated with typhoid in the model, although the study did not test whether they were sufficient for diagnosis on their own.

Age and household composition also showed adjusted associations. Patients aged 5 to 16 years had 2.50 times the odds of culture-confirmed infection compared with children under five, with a 95% confidence interval of 1.55 to 4.04. Patients over 16 had 2.16 times the odds of infection relative to the same reference group, with a 95% confidence interval of 1.41 to 3.31.

Households with two or more children under five had 1.98 times the adjusted odds of infection, with a 95% confidence interval of 1.28 to 3.07. The results show that in this study population, the adjusted pattern was not limited to children younger than five. Shared sanitation was associated with infection.

People who used a shared flush toilet had 2.42 times the adjusted odds of typhoid compared with the reference group, with a 95% confidence interval of 1.69 to 3.47 and a reported p-value below 0.001. Together with the other findings, the analysis supports the authors’ conclusion that water, sanitation and hygiene infrastructure and practices are important considerations in typhoid prevention in this endemic setting. The study itself was designed to identify associations, not to evaluate the effect of a water, sanitation or hygiene intervention, and its culture-based confirmation means that the reported outcome was laboratory-detected S.

Typhi among enrolled patients rather than all clinical cases in Mukuru.

Subject of Research: Clinical, household and sanitation factors associated with culture-confirmed typhoid fever in Mukuru, Nairobi

Article Title: Predictors and risk factors of typhoid fever in urban informal settlements of Nairobi, Kenya

Article References: Kavai, S. M., Mbae, C., Mugo, M., Kariuki, M., Imoli, D., Kawira, M., Muturi, P., Kebenei, C., Kering, K., Njuguna, A., & Kariuki, S. (2026). Predictors and risk factors of typhoid fever in urban informal settlements of Nairobi, Kenya. BMC Infectious Diseases, 26(1), Article 1708. https://doi.org/10.1186/s12879-026-14428-7

Image Credits: AI Generated

DOI: 10.1186/s12879-026-14428-7

Keywords: typhoid fever, Salmonella Typhi, Nairobi, Mukuru, observational study, persistent fever, shared sanitation, dehydration, water sanitation and hygiene, Kenya, Predictors, risk