Why is E. coli used to assess recreational water quality?
The E. coli bacterium, which is present in the feces of warm-blooded animals, is commonly associated with and is an indicator of several different disease-causing organisms, called pathogens. Viral pathogens are believed to be the major cause of swimming-associated diseases (Natural Resources Defense Council, 2009). There are more than 100 types of human pathogenic viruses that may be present in fecal-contaminated waters. Bacteria are true living cells and are larger than viruses. Waterborne bacterial pathogens in the United States include species in the genera Salmonella, Shigella, Vibrio, Campylobacter, and rare strains of E. coli. Protozoa are one-celled animals. The principal protozoan pathogens that are waterborne are Giardia lamblia and Cryptosporidium parvum.
