Question: how do you know if you have norwalk virus?
Answer: A Norwalk virus infection results in illness 24 to 48 hours after exposure, and symptoms last from 12-48 hours. Illness is characterized by the abrupt onset of vomiting and/or non-bloody diarrhea; abdominal cramps are common. 25-50% of patients report headache, nausea, malaise, myalgias and low-grade fever.