Cattle manure from a ranch in California's Salinas Valley carries E. coli bacteria that match the strain that killed three Americans and sickened 200, U.S. health officials said Thursday.
WASHINGTON -- Cattle manure from a ranch in California's Salinas Valley carries E. coli bacteria that match the strain that killed three Americans and sickened 200, U.S. health officials said Thursday.
Samples taken from three cattle at a ranch precisely match the strain of E. coli 0157:H7 taken from patients and from bags of spinach linked to the outbreak, Dr. Kevin Reilly, deputy director of the Prevention Services Division at the California Department of Health told reporters.
"This is a significant finding and it is the first time that we have linked a ... E. coli 0157:H7 outbreak to a specific ranch in the Salinas Valley," Reilly said.
Reilly said the outbreak had been traced to four farms in San Benito and Monterey counties in central California.
"Not all of them have both livestock and production of fresh spinach or produce right there right next to each other. This particular ranch that we just talked about does have that."
He said cattle were between a mile and half a mile from the spinach fields on the ranch.
The U.S. Food and Drug Administration, which is leading the investigation into the outbreak, has been expressing concern for weeks that cattle were close to spinach, lettuce and other vegetable fields on some of the farms.
Escherichia coli is a usually harmless bacteria normally resident in the guts of animals, including humans. A new and pathogenic strain called E. coli O157:H7 was identified in 1982 and now causes an estimated 73,000 cases of infection and 60 deaths in the United States each year.
Most illness has been associated with undercooked, contaminated ground beef. But if contaminated manure gets into irrigation water or is used in fertilizer, it can get onto fresh produce or the water supply.
The FDA and California health officials have been looking at irrigation practices, whether E. coli was seeping into the groundwater and the possibility animals or people may have spread the bacteria onto the produce.
It was also possible the spinach was contaminated at the packing plant, the FDA has said.
"We continue to try to determine the connection between this finding and how the spinach on the field might have been contaminated," Reilly said.
"We do not have a smoking cow at this point now," he said.
Wild pigs are common in the area and move around the fields, Reilly said. He said there was no evidence the cattle had walked through the spinach fields.
Reilly and an FDA official said tests were ongoing to see if the deadly E. coli strain could be found at the other three farms under investigation.