The Food and Drug Administration has announced that it has moved closer to identifying the source of illness for the Taco John E. coli outbreak.
FDA and the state of California, working in conjunction with state health officials in Minnesota, Iowa, and Wisconsin, have DNA-matched the strain of E. coli O157:H7 bacteria associated with the outbreak with two environmental samples gathered from dairy farms near a lettuce growing area in California’s Central Valley.
The outbreak sickened approximately 81 individuals in November and December of 2006. Illnesses were reported in Minnesota, Iowa, and Wisconsin. Twenty-six people were hospitalized, and two suffered hemolytic uremic syndrome, a serious complication of E. coli O157:H7 infection that can cause permanent kidney damage and death. No deaths have been associated with the outbreak. No new cases of illness are being reported and the outbreak is now considered over.
Epidemiological studies by Minnesota and Iowa health officials had previously identified shredded iceberg lettuce served in the restaurants as the likely vehicle of transmission in the outbreak. FDA was able to focus on specific lettuce growing regions based on the traceback from records obtained from the lettuce processor. The recent DNA match provides a clue as to one possible source of the contamination for the lettuce, although others may exist. It has yet to be determined how the E. coli contaminated the lettuce. The traceback investigation is ongoing and will hopefully yield further insight into how this contamination occurred.