SACRAMENTO, Calif. (AP) -- The U.S. Department of Agriculture on Monday issued a public health alert for raw chicken packaged at three Foster Farms facilities in California as an estimated 278 people have fallen ill in the past six months.
Strains of Salmonella Heidelberg are associated with chicken distributed to retail outlets in California, Oregon and Washington state, the USDA said in a statement.
The Salmonella outbreak has spread to 18 states, though most of the reported illnesses have been in California.
The outbreak appears to have begun in March and the USDA was notified of the illnesses in July, said Dan Engeljohn of the USDA's Food Safety and Inspection Service. Investigators had a difficult time pinpointing the source of the illnesses, Englejohn said.
A spokesman for Foster Farms said no recall was in effect and that the infections were caused by eating chicken that was undercooked or improperly handled.
The USDA has not directly linked the outbreak of illnesses to a specific product or production period. The USDA mark on suspect packages would read: P6137, P6137A and P7632.
State health officials were not planning a recall, but said it is essential that chicken be cooked to 165 degrees.
"This is the important public health issue," Anita Gore, spokeswoman for the California Department of Public Health. "Chicken can carry bacteria, and chicken needs to be fully cooked."
Gore also said people need to thoroughly wash their hands after handling raw meat, and anyone who believes they were infected and is showing symptoms like diarrhea and abdominal cramps should contact doctors immediately.
Salmonella is a pathogen that contaminates meat during slaughter and processing, and is especially common in undercooked chicken.