Emerging waterborne pathogens in the context of climate change: Vibrio cholerae as a case study

Abstract Owing to their unprecedentedly rapid appearance over the past few decades, emerging infectious diseases have become widely recognized as a global health priority. Emerging pathogens can be classified to include both newly appearing pathogens and historically prevalent pathogens with a recent shift in their biological form or geographic distribution. In the context of emerging waterborne pathogens, the latter importantly include changes in disease seasonality, vector, and host range because of climate variations. In this chapter, we discuss the reemergence of waterborne infectious disease by using Vibrio cholerae, the causative agent of cholera. This case study illustrates the mechanisms of how waterborne disease dynamics are heavily dependent on and regulated by climatic variables. In addition, it also emphasizes the impact of a compromised water and sanitation system on the spread of these pathogens, disease outbreak, and consequent epidemics. We also look at more recent attempts to predict cholera outbreaks by using macroscale environmental variables and possible implications of this for disease dynamics in the context of a changing climate. In the final analysis, as our case study illustrates, the phenomena of emerging waterborne pathogens driven by climate change are best handled in a holistic One Health approach: environmental pathogen reservoirs and human water and sanitation practices all need to be considered as important contributing factors to increasing disease threat.