ABSTRACT
The transmission of pathogens by water is a highly effective way of spreading infectious disease among large numbers of people. As early as 6000 years ago, the association of contaminated water and illness was documented in Sanskrit and Greek writings that described treatments for ‘‘impure water.’’[1] Today, waterborne disease outbreaks continue to be responsible for high morbidity and mortality worldwide (Table 1).[2,3]
CLASSES OF PATHOGENS ASSOCIATED WITH WATER
Due to the introduction of chlorination and filtration of drinking water supplies in the early 1900s, the waterborne outbreak paradigm in the United States shifted from bacteria, as the primary agents causing waterborne disease, to protozoan parasites and enteric viruses. Currently, these groups of micro-organisms and others cause water-related disease worldwide. Table 2 differentiates between the different types of micro-organisms: bacteria, viruses, protozoan parasites, blue-green algae, and helminthes. For each microbial group, examples of water-related pathogens and associated diseases are also listed.
