The likely source of an E. coli outbreak in spinach that killed three people and sickened more than 200 in the United States was a small cattle ranch about 30 miles (48 kilometers) from California's central coastline, state and federal officials said Friday as they concluded their investigation.
Authorities for the first time said they had isolated the deadly E. coli strain on Paicines Ranch in San Benito County near a field the ranch leased to Mission Organics, a spinach grower.
They found E. coli "indistinguishable from the outbreak strain" in river water, cattle feces, and wild pig feces on the ranch within a mile from the spinach fields, the California Department of Health Services and U.S. Food and Drug Administration said in a joint report.
Investigators said they could not make a "definitive determination" as to how the E. coli contaminated the spinach that reached market.
"We'll never be able to make a definitive link, but this shows the inherent risk in the area," said Patti Roberts, a spokeswoman for the health department. "Hopefully that's what good agricultural practices can address to reduce the risk in the future."
The Paicines Ranch, which breeds Angus cattle and quarter horses, said in a statement on its Web site that it leases land to crop growers and was not under investigation in the outbreak. The ranch could not immediately be reached by phone for further comment.