As of April 20, 2012, the Foundation Farm raw milk-associated Escherichia coli O157:H7 outbreak has sickened 19 persons. Of these 11 have culture-confirmed E. coli O157 infections; 15 of the 19 cases are in children <19 years of age. Four children have been hospitalized with kidney failure. Subtyping results of the E. coli O157 isolates revealed matches for eight of the human cases (three others pending); 10 samples of animal manure; two cattle rectal swabs; one swab of the milking station; and one sample of the raw milk itself.
Background: On April 10, 2012, Multnomah County Health Department received a report of a case of hemolytic-uremic syndrome (HUS) in a 1ó year old child admitted to a Portland-area hospital. Interviews with the family revealed that the child had drunk raw milk. The raw milk, which the family had obtained through a cow-share program, was produced by Foundation Farm in Clackamas County.
Foundation Farm provided the Oregon Public Health Division with contact information for 48 shareholder households. State and local health department staff were able to reach 30 households, representing 91 persons, and collected information about recent (since mid-March) Foundation Farm milk consumption, other possible food exposures, and diarrheal illness in household members.
As of April 20, 2012, a total of 19 persons report having been sickened; of these 11 have culture confirmed E. coli O157 infections; 15 of the 19 cases are in children <19 years of age. Four children have been hospitalized with kidney failure and HUS. The only common food item that all cases reported consuming was raw milk produced by Foundation Farm; none of the other food items reported were consumed by all the cases; and the households reported buying their food from a variety of stores.
On April 11, Oregon Public Health Division (OPHD) and Oregon Department of Agriculture staff visited
Foundation Farm to collect samples for testing, including from animal manure, environmental surfaces, and rectal swabs from the four cows. Leftover raw milk samples were collected on April 12 and 13 from two shareholder households for testing. All specimens positive for E. coli O157 were subtyped using pulsed-field gel electrophoresis (PFGE).
PFGE results show a single molecular pattern for eight of the human cases (three others are pending).
The same molecular type was identified in samples from the farm (10 animal manure; two cattle rectal swabs; one swab of the milking station) and from one from the leftover milk samples recovered from a case-household.