FRESNO, Calif. (AP) — Environmental samples collected from a Central California raw milk dairy's calf area tested positive for the strain of E. coli that infected five children last year, according to a letter from California health officials made public Friday.
In the letter to Organic Pastures Dairy Co. owner Mark McAfee, the California Department of Public Health said 10 of the samples taken from manure, soil, water and work surfaces at the Fresno County dairy tested positive for the kind of E. coli that can make people sick. The bacteria live in the digestive tracts of animals like cows, so it would not be unusual to find them at a dairy.
But two of the samples, according to the letter, had a genetic pattern indistinguishable from the outbreak strain.
"The fact that E. coli O157:H7 identical to the outbreak strain was recovered from OPDC environmental supports the probability that the OPDC raw milk that the case patients consumed was similarly contaminated leading to their illnesses," wrote Patrick Kennelly, chief of the health department's food safety branch.
California officials recalled and quarantined the dairy's raw milk products in November after three children who drank Organic Pastures milk were hospitalized. But officials did not find E. coli in either the company's recalled products or the bottles taken from the homes of the sickened children, and the recall and quarantine were lifted in December.
"Cows' stool is the most common reservoir of E. coli O157:H7 and it does not cause cows illness," said Bill Marler, a Seattle-based food safety lawyer. "The problem for Organic Pastures is that they not only found 10 samples that were positive for E. coli but also found two samples that were a genetic fingerprint match to the ill children. That strain is a unique strain, and it helps tie the fact that the most likely source of the children's illnesses came from the farm."
Organic Pastures Chief Operating Officer Aaron McAfee said the dairy accepts the health department's findings but remains confused about how the bacteria made it from the calf area to consumers when no milk products were found to be contaminated, and samples taken from the area where cows are milked also tested clean. Adding to the mystery is the fact that the dairy was not raising calves during the period from August to October last year when the children fell ill, McAfee said.
The company since has instituted even stricter food safety procedures, he said.
Raw milk enthusiasts say pasteurization kills bacteria beneficial to human health and argue that raw milk is medicinal and can treat everything from asthma to autism.
The U.S. Centers for Disease Control and Prevention, however, warns that raw milk can cause illness or death, with infants, the elderly, pregnant women and those with weak immune systems especially vulnerable.
From 1998 through 2008, the CDC reported 1,676 illnesses due to consumption of raw milk or raw milk products. No deaths were reported.