Drinking water-associated disease outbreaks (n = 780) reported to WBDOSS by state, 1971-2006, including 15 single cases. Drinking water-associated disease outbreaks (n = 780) reported to WBDOSS by state, 1971-2006, including 15 single cases. Thirteen outbreaks that occurred in Puerto Rico (n = 8), the Virgin Islands (n = 2), the Northern Mariana Islands (n = 1), Palau (n = 1), and the Republic of the Marshall Islands (n = 1) are not shown in the state outbreak counts but are included in the total outbreak count. Two multistate outbreaks (Alabama, Arkansas, Georgia, Kentucky, Louisiana, Missouri, North Carolina, Tennessee, Virginia, and West Virginia; Pennsylvania and Delaware), which are highlighted on the map using blue pentagons and red triangles, respectively, did not contribute to individual state counts. Numbers are dependent on reporting and surveillance activities in individual states and do not necessarily indicate that more outbreaks occurred in a given state. Gunther F. Craun et al. Clin. Microbiol. Rev. 2010; doi:10.1128/CMR.00077-09