The Washington State Departments of Health and Agricultureinvestigated the outbreak. According to the Department of Agriculture, the same strain of pathogenic E. coli O157:H7 isolated from one of the people who became ill with E. coli after drinking the raw milk was found during an inspection at the dairy.
The departments of Health and Agriculture are reminded consumers of the potential health hazards of consuming unpasteurized dairy products. "Comparing the Food Safety Record of Pasteurized and Raw Milk Products" (pdf), published at Food Safety News, highlights significant differences between the safety of raw and pasteurized milk products.
E. coli infection occurs when a person ingests Shiga toxin (Stx)-producing E. coli (e.g., E. coli O157:H7) after exposure to contaminated food, beverages, water, animals, or other persons. After ingestion, E. coli bacteria rapidly multiply in the large intestine and bind tightly to cells in the intestinal lining.
Inflammation caused by the toxins is believed to be the cause of hemorrhagic colitis, the first symptom of E. coli infection, which is characterized by the sudden onset of abdominal pain and severe cramps, followed within 24 hours by diarrhea. Hemorrhagic colitis typically occurs within 2 to 5 days of ingestion of E. coli, but the incubation period, or time between the ingestion of E. coli bacteria and the onset of illness, may be as broad as 1 to 10 days.
As the infection progresses, diarrhea becomes watery and then may become grossly bloody, that is, bloody to the naked eye. E. coli symptoms also may include vomiting and fever, although fever is an uncommon symptom.
On rare occasions, E. coli infection can cause bowel necrosis (tissue death) and perforation without progressing to hemolytic uremic syndrome (HUS)—a complication of E. coli infection that is now recognized as the most common cause of acute kidney failure in infants and young children. In about 10 percent of E. coli cases, HUS results.