Characterization of Thermotolerant Escherichia Coli and Associated Risk Factors with Contamination of Source and Household Drinking Water in Kericho District, Kenya

Abstract

Clean and plentiful water provides the foundation for prosperous communities. Changing climate patterns are threatening lakes and rivers, while key sources of drinking water are being overdrawn or tainted with pollution. Water can be contaminated with fecal material due to inadequate protection of the source, unhygienic practices of the community at the source and poor household handling practices. Water contamination exuberate its potential for greatly transmitting variety of enteric diseases. Escherichia coli is considered the most suitable index of fecal contamination. Thermotolerant (TTC) E. coli in water is used to monitor the quality of drinking water as well as disinfection indicators. Limited data exit in Kenya qualifying the safety (both from harmful bacteria and disinfectant byproducts) of drinking water for human consumption. In fact, with the poor water handling strategies both at the sources and within households especially in rural and socio-economically poor settings in Kenya calls for an urgent water quality survey to avert the water born infections epidemic waiting to occur. With this urgency, this cross-sectional study sought to determine the proportion of water (source and within the household) in Kericho district contaminated by TTC as well as evaluated factors associated with this contamination in the district. Water samples were collected aseptically using sterile sampling containers. About 100 mL of the water sample was collected and immediately analyzed for bacteriological qualities and physical chemical properties (pH, temperature, turbidity, and free chlorine) on site using a DelAgua water testing kit. Water source sampling (rivers, streams, or other surface waters) involved drawing water from 30cm below the surface. Sampling from wells and boreholes involved drawing water using a bucket and taking 100 mL into a sterile container. Water samples were filtered through a 0.45 μ m pore size membrane filter. Culture and multiplex polymerase chain reaction (PCR) techniques were used to characterize TTCs. The disk diffusion method was used for antibiotic susceptibility profiling of pathogenic E. coli. Structured questionnaire was adopted from the WHO/UNICEF Joint Monitoring Programme which was used to gather information related to water-extraction patterns, type of water transport, water treatment methods, hygiene and sanitation related issues. A total of 103 households consented and their household and source waters collected. Majority (30.1%) of the households were located within the Kericho Township, (68.9%) were in the rural locality, (95.1%) were female and (42.7%) were aged 21 to 30 years. The respondents mean age was 21.59 years, the range (18–29 years) was the majority. The main water source was river (36.9%) and only (33%) had piped or municipal supply. Most (43.7%) of the households had drinking water source within their premises while (13.6%) had to walk for 30 to 60 minutes to water source. Majority 60.2% of the household used clay pot for water storage; most of them (91.3%) did not treat their drinking water. The majority (83.5%) drew drinking water by dipping the cup into the water storage container. About (59.2%) did not wash their hands before drawing water while (96.1%) of them rinsed the water drawing utensils. There were 48/103 (46.6%) households whose drinking water was contaminated by Thermotolerant coliform (TTC) levels of >10cfu/100ml. Five (10.4%) of these 48 TTCs were toxigenic E. coli including 2/5 (40%) Enteroaggregative E. coli (EAEC), 2/5 (40%) Enterotoxigenic E. coli (ETEC) and 1/5 (20%) Enteropathogenic E. coli (EPEC). All of this pathogenic E. coli were resistant to commonly used antibiotics such as Cephalothin, Ampicillin, Tetracycline, Ampicillin/sulbactam and Sulfamethoxazole/trimethoprim. Rural household locality (OR 2.01, 95% CI 1.09 to 4.12) and hand contact with drinking water during water withdrawal (OR 1.11, 95% CI 1.11 to 3.39) increased the likelihood of water TTC contamination. However, household whose main source of drinking water was from piped supply or from municipal (OR 0.38, (95%) CI 0.16 to 0.91), washed their drinking water storage containers (OR 0.58, 95% CI 0.31 to 0.99), washed hands before drawing drinking water (OR 0.33, 95% CI 0.15 to 0.67), households whose total coliforms count was less than 10 cfu/100ml (OR 0.45, 95% CI 0.26 to 0.81) and household water source temperatures was between 15 to 20oC (OR 0.39, 95% CI 0.16 to 0.96) were less likely to have household drinking water contaminated with TTC. This study shows that significant number of household drinking water in this study were contaminated with TTC including toxigenic multi-drug resistant E. coli. These strains are associated with great mortality and morbidity especially among children and immunocompromised population. The study recommends continuous monitoring of both water sources and household for contamination and that water treatment of any kind could reduce the level of TTC contamination. Further the study showed that by improving on hygiene and protecting water source are simple implementable steps household could adopt to improve the quality of drinking water in the district.