If monica fears she has eaten food that may cause listeriosis, how soon might she experience symptoms of the illness

The symptoms of listeriosis develop a few days after eating contaminated food, but it may take as long as 30 days or more before the first sign and symptoms of infection begin. The listeriosis symptoms include fever, muscle ache, Nausea and diarrhea. The listeriosis may spread to the nervous system which led to sign and symptoms such as stiff neck and headache