Assessment of health risks associated with microbial contamination of springs among slum residents in Kinawataka, Nakawa Division, Kampala, Uganda

Abstract

Springs, the most utilised source of water in informal settlements, are at high risk of contamination from poor sanitation and waste disposal, threatening residents' health. However, there is limited evidence quantifying health risks from contaminated spring water in Uganda. This study aimed to assess human health risks associated with the microbiological contamination of springs in the Kinawataka slum in Kampala. A cross-sectional study design was employed involving quantitative data collection through sanitary inspections, water quality analyses and the quantitative microbiological risk assessment (QMRA) across 7 springs and 287 households. Water samples from the households and springs were collected and analysed from the National Water Quality Reference Laboratory. Microsoft Excel and Stata 14 statistical software were utilised for data management and analysis. The significance of the associations employed appropriate tests such as Fisher’s Exact and the Wilcoxon rank-sum tests. Sanitary conditions around the springs were poor, with six of the seven classified as high-risk due to inadequate fencing and proximity to pollution sources. The microbial water quality analyses indicated that five of the seven springs posed a risk due to contamination with E. coli. A high proportion, 84.32% (242/287) of the respondents utilised spring water for drinking. Despite 62.72% (180/287) of the residents treating their water, 71.43% (205/287) of drinking water samples collected from households were contaminated with Escherichia coli. A daily infection risk of 0.148, translating to a daily risk of illness of 0.037 and an annual risk of infection approximating 1.00 (0.993) were estimated from the QMRA, indicating a high risk of waterborne diseases among the residents of Kinawataka slum. This study highlighted that contaminated water sources, particularly in the Kinawataka slum, pose a significant public health risk. This calls for targeted interventions to enhance water safety in these communities.

Keywords: Microbial contamination, Slum residents, Kinawataka, Nakawa Division