New samples, taken from the California ranch from which the outbreak of E. coli in spinach appears to have originated, indicate wild pigs as a likely culprit in spreading the bacteria into spinach fields and spurring the outbreak.
A sample taken from a wild pig killed on the property tested positive for the same strain of E. coli that caused 204 illnesses and three fatalities. Five other samples also tested positive for the strain, four coming from cattle on the same ranch and one from a creek downstream from the spinach fields.
Kevin Reilly, deputy director of the California Department of Health Services, says wild pigs were a "real clear vehicle" for transporting the bacteria from the cattle to the spinach.
"Those wild pigs are up and down that waterway," he says.
After smashing down fences, the wild pigs could have spread the bacteria by defecating on the spinach or by tracking it into the field on their feet, Reilly says.
Reilly reports that the investigation has shown the contaminated spinach was conventionally grown, came from just four ranches, and was all processed on the same day. Organic spinach was not involved in the outbreak, the investigation found, as no organic spinach was processed on the same day as the contaminated spinach.
The FDA confirms that the outbreak is over. "We have no evidence to suggest people should not be eating spinach from other places - except from these four ranches," says Jack Guzewich, of the FDA's Center for Food Safety and Applied Nutrition. "And they're no longer producing spinach this season."