Eighteen people infected with the outbreak strain of Listeria have been reported from nine states since July 5, 2015. The number of ill people reported from each state is as follows: Connecticut (1), Indiana (1), Massachusetts (1), Michigan (4), Missouri (2), New Jersey (1), New York (5), Ohio (2), and Pennsylvania (1). Whole genome sequencing has been performed on clinical isolates from all ill people and has shown that the isolates are highly related genetically.
Listeria specimens were collected from ill people between July 5, 2015 and January 31, 2016. Ill people range in age from 3 years to 83, and the median age is 66. Seventy-two percent of ill people are female. All 18 (100%) ill people were hospitalized, including one person from Michigan who died as a result of listeriosis. One of the illnesses reported was in a pregnant woman.
State and local health departments and federal investigators continue to interview ill people about the foods they may have eaten or other exposures in the month before their illness began. Of eight ill people who were asked about packaged salad, all eight (100%) reported eating a packaged salad. Four (100%) of four ill people who were able to specify the brands of packaged salad they ate reported various kinds of Dole brand packaged salad.
On January 27, 2016, Dole voluntarily recalled all salad mixes produced in the Springfield, Ohio processing facility. At this time, there is no evidence to suggest that any products produced at other Dole processing facilities in the United States are linked to illness. The type of salad mixes produced at this facility were packaged in bags and plastic clamshell containers and can be identified by the letter “A” at the beginning of the manufacturing code on the package.
According to the Public Health Agency of Canada, there are seven people in five Canadian provinces infected with the same outbreak strain of Listeria. Laboratory tests performed to date on clinical isolates from ill people in Canada showed that the isolates are highly related genetically to Listeria isolates from ill people in the United States. Packaged salads produced at the Springfield, Ohio Dole processing facility were distributed in Eastern Canada and the United States. Additionally, the Public Health Agency of Canada confirmed the presence of Listeria in packaged salads produced at the Dole Springfield, Ohio processing facility.