Animal Waste, Water Quality and Human Health

Exposure interventions 287species that prefer to take blood meals from animals rather than from humans)deserves mentioning. This zooprophylaxis approach implies management of thespatial distribution of livestock and therefore also has relevance to themanagement of animal waste to avoid contamination of water bodies. Anextensive literature on zooprophylaxis for vector-borne disease control exists(Bogh et al. 2001, Kawaguchi et al. 2004, Mathys 2010).Integral to all these malaria control options is the need for public educationsuch that local populations understand the relationship between certainbehaviours (be they personal, cultural or linked to agricultural practices) andtransmission of disease. In the case of waterborne microbial pathogens the load,transport and exposure mechanisms may not be as clearly defined as for malaria,necessitating an investigative approach to identify the pollutant source prior tothe development of exposure interventions.8.2.2 Faecal indicator organisms as a gauge of water qualityGlobal water quality standards and analytical methods to detect watercontamination may differ in some aspects, but they are primarily or exclusivelybased on percentage compliance with faecal indicator bacteria levels (totalcoliforms, faecal coliforms, enterococci, and E. coli) (WHO 1999). Regardlessof the indicator employed, all imply faecal contamination has, at least in part, ahuman origin and none explicitly address the specific contribution of faecalcontamination of non-human origin to any risk assessments, based on past andrecent epidemiological studies (Gleeson & Gray 1997). However, the etiologicagents implicated in the transmission of waterborne disease may originate froma variety of direct and indirect sources (Calderon et al. 1991, Bartram & Rees2000, Solo-Gabriele et al. 2000, Noble et al. 2003). Among these sources, aclearly defined association exists between human exposure to water of poorquality resulting from agriculture and/or animal husbandry and the transmissionof zoonoses.Faecal indicators used to gauge water quality may be loosely correlated withpathogen presence dependent on the source of pollution (Kueh 1995, Marinoet al. 1995, Schiff et al. 2007). While direct pathogen analysis would bepreferable, the array of organisms capable of transmitting disease to humans viaexposure to the water environment make individual analysis impractical for avariety of reasons including the cost and technical expertise necessary to executethe assays. Therefore, despite the fact that current binary indicator schemesleave room for confounding factors, compliance with best management practicesneed not be inhibited and may move forward with available data beingtranslated into useful information for intervention.