# Assessing the environmental and climatic influences on the incidence of severe typhoid in Kampala, Uganda

## TL;DR

This study examines how rainfall and water quality in Kampala, Uganda, influence the incidence of severe typhoid, finding a strong seasonal link.

## Contribution

The study introduces a point-of-use water testing approach to assess typhoid risk and links it to climatic factors in an urban African setting.

## Key findings

- Monthly rainfall amounts show a positive correlation with severe typhoid cases in Kampala.
- Surface water sources in Kampala pose moderate to severe disease risk due to microbial contamination.
- Typhoid incidence is weather-sensitive and predictable, with consistent annual peaks.

## Abstract

Typhoid is a water and foodborne febrile illness which often mimics malaria in endemic African nations. This study deployed a point-of-use water testing approach to assess the public health risk associated with the consumption of water from spring wells (open or closed wells) and boreholes in off-grid areas in Kampala, and then assessed the correlation between incidence of in-patient typhoid cases at the local health facilities, and monthly rainfall amounts in Kampala.We retrieved 10-year archived data on monthly incidence of severe typhoid in-patient cases and corresponding data on monthly rainfall amounts and evaluated the interrelation between monthly rainfall and the incidence of inpatient department cases using regression and time-series analysis. The Portable Microbiology Laboratory was used to determine the level of disease risk associated with currently used underground water sources in Kampala. There was positive correlation between monthly rainfall amounts and incidence of severe typhoid cases in Kampala with a strong seasonal component with consistent annual peaks. The surface water sources in Kampala pose moderate to severe disease risk to the user communities and should be monitored and tested for microbial quality to ensure public health safety. Typhoid incidence in Kampala is weather-sensitive and predictable. Environmental modifications and vaccination could prevent the strong annual peaks of severe typhoid.