Norovirus surveillance system provides near real-time tracking of cases

Norovirus gastroenteritis is characterized by sudden onset of nausea, vomiting, watery diarrhea and abdominal cramps that develop following a 12to 48-hour incubation period. Systemic symptoms such as fever, malaise, myalgia and headache also may occur. Symptoms typically last 24 to 60 hours, but longer courses can occur in young children and the elderly in whom dehydration can be a major problem.