The Rhode Island Department of Health is advising residents, staff, volunteers, family and friends who attended a cookout at the Rhode Island Veterans Home in Brtistol on Friday, Sept. 7, and ate uncooked onions that they may have been exposed to listeria monocytogenes.

The dietary supervisor for the Veterans Home received an email from U.S. Foods indicating that random sampling by the Food and Drug Administration of onions from one of their suppliers found one positive result for the presence of Listeria in one lot of onions. The Veterans Home received three cases of diced onions potentially from that lot on Sept. 6.

None of the recalled foods are available at retail, according to U.S. Foods. The Health Department will continue to monitor the recall for expansion.

Symptoms of listeriosis can include high fever, severe headache, stiffness and nausea, or abdominal pain and diarrhea. Pregnant women, young children, frail and elderly people are particularly at risk. Anyone who ate these onions and experiences these symptoms within the next 70 days should contact their healthcare provider.

No illnesses have been reported. Residents and staff are being monitored. Visit  www.cdc.gov/listeria/definition.html for more information about listeria.