Water-based disease and microbial growth

What are water-based diseases? According to Bradley (1977) water-based diseases (WBDs) are caused by helminths that have a life cycle involving an aquatic invertebrate animal. These helminths may be ingested in water or food (vegetable or animal) or enter the body through the skin during recreational or occupational exposures to water. Many of these diseases are also associated with defective sanitation (American Water Works Association, 2006). There is also a range of protozoa, bacteria, dinoflagellates, diatoms and cyanobacteria that live in water and infect humans directly or through ingestion of contaminated shellfish. These microorganisms and the diseases they cause are also considered water-based in this chapter and are summarized in Table 5.1.