Animal Waste, Water Quality and Human Health

Assessing the importance of zoonotic waterborne pathogens 53populations and cause infection in humans) from closely related agents that areeither human or animal host-specific and are not zoonotic. While outbreak dataare helpful in assessing the frequency and severity of waterborne diseaseassociated with specific zoonotic waterborne pathogens, it is thought that asmuch as 90% of illness associated with specific agents is sporadic. Mostsporadic illness is under-diagnosed and therefore under-reported even indeveloped countries. Further, certain pathogens such as Campylobacter, whilehighly prevalent, are rarely associated with outbreaks. In the assessment of theseverity of illness, not only short-term morbidity and mortality must beconsidered but also the long-term sequelae of these infections. Hypertension,diabetes, renal insufficiency, central neurological defects, polyneuritis,inflammatory bowel disease and other chronic conditions, have been shown tooccur post infection with certain of these pathogens. These chronic conditionscan significantly compromise the long-term health of individuals. The highestrisk of infections with waterborne zoonotic pathogens occurs inimmunologically naive or compromised members of the population such aschildren and the elderly, infection rates are highest in rural regions with highanimal densities and in regions where water treatment is poor or nonexistent.Occupational and recreational exposure to water contaminated with animalexcreta has also been shown to be an important route of infection. In addition tothe spread of infectious agents, the spread of genetic determinants associatedwith increased virulence and resistance to biocides such as antibiotics and theirtransfer from pathogens and nonpathogens in animal and their environment tohuman pathogens via animal excreta and indirectly through water to humans isalso a concern. However, further studies are needed to determine the persistenceof these determinants in animal excreta and water and the conditions in thesemedia such as biofilms which facilitate the transfer of these determinants tohuman pathogens. Improved and at the same time economically feasibleintervention strategies are required to prevent the transmission of zoonoticwaterborne pathogens and specific virulence and AMR genetic determinantsthrough water.REFERENCESAbe, N. (2004). Molecular and phylogenetic analysis of Blastocystis isolates from varioushosts. Vet. Parasitol., 120, 235–242.Abe, N., Nagoshi, M., Takami, K., Sawano, Y. and Yoshikawa, H. (2002). A survey ofBlastocystis sp. in livestock, pets, and zoo animals in Japan. Veternary Parasitology,106, 203–212.