Longitudinal study of microbial load of drinking water and seasonal variation of water quality at the point of use in food establishments of Addis Ababa, Ethiopia

The study aimed to determine the status of microbial load of drinking water and seasonal variation of water quality. An institution-based longitudinal study was conducted. 1,141 food establishments were divided into slum and non-slum areas based on their location. Moreover, they were categorized as large and small food establishments. Then, 125 food outlets were selected using a simple random sampling technique. From the selected food outlets, 250 drinking water samples were collected directly from the drinking water storage in the rainy and the dry seasons. Data analysis was conducted using a repeated-measure ANOVA statistical model. The finding indicated that, 26.4% and 10.7% of the food establishments’ drinking water was positive for Escherichia coli in the wet and the dry season, respectively. Moreover, 3.2% and 1.6% of the food establishments’ drinking water had very high health risk to customers during the wet and the dry season, respectively. The drinking water at the point of use was found to be vulnerable to microbiological contamination and had a serious health risk. Therefore, good sanitation and proper handling of drinking water, and effective drinking water treatment, such as disinfection and filtration, should be practiced in all food establishments.