Waterborne Diseases Waterborne Disease Outbreaks Associated with Drinking Water Cause of Outbreak Percentage Parasitic(Cryptosporidium,Giardia) 35.3 Unidentified 29.4 Bacterial (Salmonella,Campylobacter, etc.) 23.5 Chemical (pesticides,nitrates,excess fluorides) 11.8 Waterborne Disease Outbreaks Associated with Recreational Water Cause of Outbreak Percentage Cryptosporidium 50.0 E.coli O157:H7 16.7 Unknown 16.7 Norwalk-like viruses 11.1 Shigella 5.6 Table 27.2 Waterborne Diseases Table 27.2