Zoonotic Waterborne Pathogen Loads In Livestock

Abstract

This chapter provides an overview on the prevalence and environmental load of waterborne zoonotic pathogens of public health importance shed in the excreta of livestock. Chapter 2 presents the five zoonotic pathogens that will be reviewed in this book: Cryptosporidium parvum, Giardia duodenalis, Escherichia coli O157:H7, Salmonella, and Campylobacter. These protozoa and bacteria are important disease-causing agents and satisfy the three criteria agreed to be classified as priority one waterborne zoonotic pathogens associated with livestock populations: capacity to induce clinical illness in susceptible humans, capability to be transmitted to humans through water, and prevalence in a biological reservoir host including one or more livestock species. A biological reservoir is defined as a host (in the context of this book: a livestock species) that allows thepathogen to amplify or reproduce and not merely pass through. Information on the prevalence, intensity and environmental load of these five pathogens is presented along with methodological concerns on how we draw inferences from these measures of occurrence and the human health risk they represent. Important aspects of the ecology and epidemiology of these five pathogens in livestock populations are also discussed in as much as they may be useful in the development of intervention strategies to limit their prevalence in livestock and to reduce the risks of waterborne transmission to humans.