gastrointestinal disorders
Norovirus Gastroenteritis
Introduction
Norovirus is a common cause of diarrhea. Symptoms are vomiting, abdominal cramps, and diarrhea that usually resolve in 1 to 3 days. Diagnosis is based on clinical suspicion, and polymerase chain reaction testing as part of a multiplex panel for a variety of causes of acute gastroenteritis can be done. Treatment is supportive with oral fluids; in more severe cases, IV fluids may be needed. Since the introduction of rotavirus vaccines, norovirus has become the most common cause of acute sporadic and epidemic viral gastroenteritis in the United States in all age groups, including in children; the peak age is between 6 months and 18 months. Infections occur year-round in the United States, but most occur from November to April ( Reference ). Large waterborne and foodborne outbreaks occur. Person-to-person transmission also occurs because the virus is highly contagious. Norovirus causes most cases of gastroenteritis epidemics on cruise ships and in nursing homes. Incubation period is 24 to 48 hours. (See also Overview of Gastroenteritis .) 