Field Survey on Microbial Contamination Associated with Waterborne Diseases in a Low-income Settlement of Lusaka, Zambia

Many children suffer from diarrhea in low-income settlements. However, little information is available on the microbial contamination related to waterborne diseases. Microbial contamination of five environmental media (groundwater, tap water, stored household water, drinking cups, dish sponges) was investigated in Chawama ward, Lusaka, Zambia. Escherichia coli was measured by culture method. Seven waterborne pathogens (rotavirus A, norovirus GII, Shigella spp., Vibrio cholerae, enterotoxigenic E. coli (ETEC), Campylobacter jejuni, Cryptosporidium spp.) and fecal genetic markers (human, pig, chicken) were detected by quantitative PCR. The concentrations of E. coli in groundwater and tap water were under 5 colony forming unit (CFU)/100 mL. High concentrations of E. coli were observed in 3 of 20 stored water samples (> 100 CFU/100 mL) and on 5 of 20 cups (> 1,000 CFU/media). Rotavirus A, Shigella spp. and ETEC were detected on cups. Presence of I1 genotype of human rotavirus A was identified by nested PCR and amplicon sequencing for a partial region of the VP6 gene. C. jejuni and a chicken-associated genetic marker were detected from tap water, stored water, cups and sponges, suggesting that chicken would be the main cause of microbial contamination. These results indicate the various transmission routes of enteric pathogens in this area.