Food Safety News reports, USDA’s Food Safety and Inspection Service (FSIS) issued a public health alert Monday after an estimated 278 illnesses in 18 states caused by Salmonella Heidelberg were linked to consumption of raw chicken produced at three Foster Farms facilities in California.

FSIS said while the illnesses had not been been linked to a specific product or production period, raw chicken from the company’s California facilities bear one of the these establishment numbers inside a USDA mark of inspection or elsewhere on the package: “P6137,” “P6137A,” and “P7632.” The products were mainly distributed to retail outlets in California, Oregon and Washington state.

Foster Farms released a statement on Monday noting that no recall of its chicken products is in effect and emphasizing that people should safely handle raw chicken products and make sure that raw chicken is thoroughly cooked before consumption.

“While the company, FSIS and CDC continue to investigate the issue, Foster Farms has instituted a number of additional food safety practices, processes and technology throughout company facilities that have already proven effective in controlling Salmonella in its Pacific Northwest operations earlier this year,” the company stated.

FSIS noted that it is continuing to investigate the Salmonella Heidelberg infections, along with monitoring by the Centers for Disease Control and Prevention and state health departments in the affected states.

However, the FSIS alert stated that, “The investigations indicate that consumption of Foster Farms brand chicken and other brand chicken produced at Foster Farms plants are the likely source of this outbreak of SalmonellaHeidelberg infections. Illnesses were linked to Foster Farms brand chicken through epidemiologic, laboratory and traceback investigations conducted by local, state, and federal officials.”