The buffet food at an Illinois health department's Christmas party made 42 individuals sick.
Phyllis Wells, head of the Lawrence County Health Department, said that the cause of the outbreak hasn't been officially determined, although a norovirus is suspected.
People can get the virus by consuming infected food or drink, contact with people or objects and then their mouths.
It is believed that the ham at the salad bar is the culprit. State health officials are still investigating the matter.
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