State and federal officials confirmed Thursday that the E. coli they discovered in cattle manure near a Salinas Valley spinach field is the same strain that contaminated spinach and sickened nearly 200 people across the U.S.
The discovery is especially significant because it marks the first time an investigation of an E. coli outbreak has ever turned up a matching sample near the source of the tainted produce. However, Kevin Reilly, deputy director of prevention services with the California Department of Health Services, says "We do not have a smoking cow at this point."
The E. coli strain turned up in three samples of cattle feces taken from a ranch between a half-mile and a mile away from spinach. Given this proximity, "It's very easy to think the water was contaminated," says Alejandro Castillo, associate professor of food microbiology at Texas A&M University.
The operator of the spinach farm leases that land from the cattle ranch owner. A paved road and fences separate the two operations.
This investigation raises questions about potential rules separating livestock pasture and produce fields. "You have to create zones around the field to make sure the cattle manure can't get into the farm field," says Caroline Smith DeWaal, food safety director for the Center for Science in the Public Interest. "To narrow the solution to one field or one group of cattle would be missing the more systemic problem that may exist in the Salinas Valley."
But some farmers and cattlemen are concerned about having to create buffer zones within their property between cattle and produce.
"You're talking about huge amounts of private property," says Bob Perkins, executive director of the Monterey County Farm Bureau.
Authorities narrowed the source of the contamination to four farms in Monterey and San Benito counties, and have collected more than 650 samples in the area.