Legionella and Campylobacter bacteria have been implicated in nearly three-fourths of recent disease outbreaks linked with drinking water.
The Waterborne Disease and Outbreak Surveillance System shows that during 2009 to 2010, public health officials from 17 states reported 33 drinking water outbreaks. As a result, 1040 people became ill, 85 were hospitalized, and 9 died. Legionella was implicated in 19 outbreaks, 72 illnesses, 58 hospitalizations, and 8 deaths. Campylobacter was the sole microbe implicated in 4 outbreaks that caused 812 illnesses and 17 hospitalizations, as well as in 2 outbreaks with more than 1 organism involved that resulted in 17 illnesses.
Legionella Poses Major Challenge in Waterborne Disease Outbreaks. JAMA. 2013;310(17):1786. doi:10.1001/jama.2013.280218