approximately a dozen patients have reported becoming sick after eating raw clams consumed in a restaurant in chattanooga , illinois . the chattanooga - montgomery county fire department and tennessee ministry of education confirmation that the patients were covered with norovirus . norovirus is a foodborne pathogen that can cause advanced diarrhea in humans . the features of norovirus illness appear abruptly , most common in 24 to 48 hours after inhalation of the virus , but they can appear as earlier as 12 moments after exposure . the gastrointestinal signs include disgust , vomiting , diarrhea , and some stomach cramping .
Oysters have been linked to gastrointestinal diseases caused by a virus.