Safe drinking water: to what extent are shallow wells reliable?

Our study investigated the presence of Cryptosporidium hominis-parvum-meleagridis and Giardia duodenalis in shallow wells used for drinking water (DW) in a rural area. Also, bovine feces were collected from their vicinity. Our findings highlight significant potential risks associated with these pathogens in DW sources. Due to the COVID-19 pandemic, samples were collected in two phases: September/2019 to March/2020 and October/2021 to April/2022. Water samples (n = 69) and feces (n = 13) were collected biweekly and analyzed using the USEPA 1623.1 method and molecular tools for species identification, and feces by direct DNA extraction. During the first phase, oocysts and cysts were detected at frequencies ranging from 9.1 to 41.7 and 27.3 to 83.3, respectively. In the second phase, oocyst frequencies ranged from not detected to 25%, while cyst ranged from 18.2 to 83.3%. Escherichia coli concentrations were significant at all collection points. C. hominis-parvum-meleagridis and G. duodenalis were notably detected in bovine feces. Our study revealed the presence of anthropogenic parasites and E. coli in DW sources intended for human consumption. These findings underscore the urgent need for preventive measures to ensure safe DW and prevent future contamination. Effective water quality surveillance is crucial in this regard.