food may be contaminated by food preparers or handlers who have viral gastroenteritis especially if they do not wash their hands regularly after using the bathroom. shellfish may be contaminated by sewage and persons who eat raw or undercooked shellfish harvested from contaminated waters may get diarrhea. drinking water can also be contaminated by sewage and be a source of spread of these viruses.
how does food get contaminated by gastroenteritis viruses?