Surveillance for Waterborne Disease Outbreaks Associated with Drinking Water --- United States, 2007--2008

Surveillance for Waterborne Disease Outbreaks Associated with Drinking Water --- United States, 2007--2008

Etiology

Of the 36 drinking water--associated outbreaks, 21 (58.3%) were caused by bacteria, five (13.9%) were caused by viruses, three (8.3%) were caused by parasites, and one (2.8%) was caused by a chemical. Two (5.6%) outbreaks had multiple etiologies: one (2.8%) was caused by bacteria and viruses, and one (2.8%) was caused by bacteria and parasites. Four (11.1%) had unidentified etiologies: one was suspected to be caused by norovirus (Table 8; Figure 5).