METHODS: After receiving a report from a local daycare center of two children diagnosed with salmonellosis on August 24, Alaska SOE collaborated with the Municipality of Anchorage (MOA) to investigate the cause of the outbreak. PFGE was performed on all Alaska Salmonella isolates at the State of Alaska Public Health Laboratory (ASPHL) per CDC PulseNet protocol.
RESULTS: On August 28, ASPHL reported six patients that tested positive for Salmonella Poona with indistinguishable PFGE patterns. A total of seven laboratory-confirmed and three probable cases were identified. MOA public health nurses joined daycare center staff to interview ill persons for risk factors associated with salmonellosis. As the national outbreak evolved and cucumbers were named a possible source, investigators discovered that cucumbers were served at the daycare center. On August 28, daycare center staff were advised to throw away all cucumbers. As of December 15, 19 laboratory-confirmed and 6 probable cases were identified in Alaska with onset dates ranging from July 28 to November 28; 19 of 22 patients were female. Patient ages ranged from 3 months to 75 years; 19 of 22 patients were aged <18 years. Cucumber consumption was explicitly reported by 14 of 19 laboratory-confirmed patients. The Alaska Department of Environmental Conservation initiated a trace-back investigation on August 31 and determined that cucumbers consumed by patients were sourced from the same local produce distributor, who obtained cucumbers from California distributor Andrew & Williamson (A&W) Fresh Produce.
CONCLUSIONS: Early on in the nationwide investigations, the Alaska subcluster investigation assisted in strengthening the association of the Salmonella outbreak with cucumbers. The trace-back resulted in A&W issuing two recalls of cucumbers. Additional cases with PFGE patterns indistinguishable to the outbreak strain continue to be reported.