Giardia and Cryptosporidium: Occurrence in Water Supplies

Waterborne outbreaks of gastroenteritis have economic consequences beyond the cost of health care for affected patients, their families and contacts, and the economic costs of illness and disease, as they also create a lack of confidence in potable water quality and in the water industry in general. This article explores different aspects of Giardia and Cryptosporidium and other emerging waterborne protozoan parasites and, in particular, the epidemiological aspects of Giardia and Cryptosporidium associated with the contamination of drinking water supplies, their detection by current methods, and the availability of new rapid and sensitive methodology, and finally, control strategies to reduce environmental contamination. Cryptosporidium oocysts and Giardia cysts are transmitted by the fecal-oral route. The impact of the anthropogenic and environmental factors and climate change the contamination patterns of waterborne protozoan parasites, and these climate and demographic changes will affect the quality of the water resources. Better surveillance and management strategies are needed to assess the risk of waterborne transmission of pathogenic protozoa, and effective wastewater treatment is a critical link to protect the public health against epidemic enteric protozoan infections.