Fecal viral concentration and diarrhea in norovirus gastroenteritis

Fecal viral concentrations of 40 patients infected with norovirus genogroup GII.4 correlated with diarrhea duration and frequency of vomiting. Higher viral concentration and older age were independently associated with prolonged diarrhea (>= 4 days). These findings provide information on the pathogenesis and transmission of norovirus infections.