In June 2012 the CDC announced an investigation by public health officials of an outbreak of E. coli O145 infections. A total 18 persons infected with the outbreak strain were identified. Case-patients resided in 9 states: Alabama (2), California (1), Florida (1), Georgia (5), Kentucky (1), Louisiana (5), Maryland (1), Tennessee (1) and Virginia (1). Among persons for whom information was available, illness onset dates ranged from April 15, 2012 to June 12, 2012. Ill persons ranged in age from 1 year to 79 years old, with a median age of 33 years old; 78% were female. Four ill persons were hospitalized; a Louisiana child died. Based on interviews conducted, a source for these infections was not identified.