Animal Waste, Water Quality and Human Health

may not be an effective intervention measure due to the extent of the habitat and itsecological characteristics. Prevention of contact with infested waters may alsoprove difficult in regions where there are few alternatives with respect tosanitation, agricultural practice and recreational venues. In spite of thesechallenges, effective eradication campaigns have been mounted in endemiccountries in other parts of the world where the intermediate host is strictlyaquatic, like sub-Saharan Africa. For example, using school-based publiceducation (essay writing, video recorded dramas, and household sanitationobservations), public health officials in Tanzania have successfully broken thecycle of transmission using children to change or improve personal practiceswithin their communities (Freundenthal et al. 2006). A survey of respondentsfrom Guangxi, China, noted eradication of schistosomiasis provided clearbenefits in terms of agricultural outputs and improved farming conditionsthrough increased work capacity and that long term maintenance strategiesneeded to continue (Sleigh et al. 1998). On the other hand, a study from OsunState, Nigeria, determined that neglect of environmental effects of developmentprojects, such as dam construction, were thought to counteract eradicationefforts and allow transmission to remain unabated in the absence of nationalcontrol programme (Oladejo & Ofoezle 2006).8.4.2 LeptospirosisExposure interventions 297Leptospirosis is found throughout the world, as an endemic condition in tropicalclimates and as a seasonal illness in more temperate climates. It is a truezoonosis with infection being maintained in the animal host and transmissionoccurring only when there is direct contact with the animal reservoir (Bolinet al. 2004). Passed to the environment in urine, the pathogen can surviveoutside the host for several weeks (e.g. L. interrogans survives in surface watersand moist soil for months) presenting a significant exposure risk to thoseindividuals coming in contact with contaminated water through agriculturalpractices, aquaculture, sanitation, or leisure time pursuits (CDC 1993, Naritaet al. 2005). The prevalence of leptospirosis is highest in those in contact withdomesticated animals (agriculture, butchers and animal handlers) or the excretaof infected animals and humans (sanitation workers) (Sharma et al. 2006). Whilethe ubiquitous nature of this organism in the environment contributes to itssuccess as a zoonotic pathogen, that attribute also presents challenges forintervention strategies.Testing for the presence of leptospires in water is not practical, considering theirfastidiousness and time required for growth in laboratory media. A high probabilityof animal contact with water and a high density of rodents in alkaline water bodies