Factors associated with severe and prolonged disease are immunodeficiency and immune suppression, comorbid disease, and malnutrition. A similar spectrum of severity exists for adults, but severe illness is most common in elderly patients with comorbid disease. Viruses are the suspected cause of acute gastroenteritis when vomiting is prominent, when the incubation period is longer than 14 hours, and when the entire illness is over in less than 3 days. Vital signs are usually normal. Temperature may be slightly elevated.
High fever suggests bacterial infection.
Tachycardia and hypotension suggest severe dehydration. Other signs of dehydration include poor skin turgor, dry mucous membranes, and extreme fatigue or drowsiness. The abdominal exam may demonstrate mild tenderness. Severe abdominal pain and tenderness suggest bacterial infection or an abdominal emergency. Acute infections with Group C are quite frequent in the US and worldwide.