This study sought to build up evidence surrounding the risks that livestock pose to human health through contact with drinking-water. Some analyses are ongoing, but to date we found that it was difficult to reliably observe contact between livestock and water sources using existing protocols.
Funding Sources: Medical Research Council, £96,015
Start Date: 1/4/2017
End Date: 31/07/2019
There is growing evidence that contact between livestock and people may be implicated in disease transmission, including in the transmission of diarrhoeal pathogens such as Cryptosporidium via domestic water. This MRC/DfID-funded project sought to develop evidence concerning contact between livestock and domestic water and its consequences for water contamination and health. The project brought together a multi-disciplinary team from the Kenya Medical Research Institute (KEMRI), VIRED International and University of Brighton. We examined several techniques for understanding such contact and measuring related water contamination.
A team of six surveyors with differing backgrounds independently visited a variety of rural water sources in rural western Kenya, separately observing contamination hazards (including the presence of livestock, fencing, and animal faeces) at each source. We found that the most experienced observer recorded more contamination hazards than his colleagues and only modest agreement between the observations made by different observers. This suggests that further refinement of contamination observation protocols is needed, if reliable and consistent observations are to be made.
Colleagues at University of Brighton worked to develop a phage-based microbial source tracking technique, working with environmental samples from western Kenya. Most standard microbial water testing relies on faecal indicator bacteria, which signify faecal contamination of water but do not identify the source of such contamination. In contrast, microbial source tracking techniques enable the source of faecal contamination – whether from humans or livestock – to be identified. Brighton’s phage-based technique relies on microbiological predator-prey relationships between phages and host bacteria to identify the source of contamination. Working with KEMRI and VIRED colleagues, the team successfully isolated candidate Bacteroides hosts from environmental samples and piloted the technique in Africa for the first time. The team also organised a workshop, sharing their expertise on techniques such as enumeration of phages in environmental samples with Kenyan microbiologists.
As part of the study, we also examined the use of several other techniques for identifying livestock contact with domestic water, including participatory mapping, the tracking of livestock via GPS collars, and observation of contact with livestock in the home. Analysis of these data is ongoing.