Norovirus gastroenteritis [Norovirus-gastroenteritis]

Viruses are the leading cause of acute gastroenteritis. In adults, noroviruses are the most common cause of gastroenteritis in sporadic cases and also in outbreaks whereas rotaviruses account for the majority of cases of viral gastroenteritis in childhood. Noroviruses are frequently associated with outbreaks in hospitals and nursing homes. The clinical manifestations of gastroenteritis include diarrhea and vomiting as the main symptoms. In immunocompromised patients clinical manifestations may be atypical, such as chronic diarrhea, weight loss and malnutrition. Nucleic acid based PCR tests are the mainstay of diagnosis; however, because of the characteristic clinical symptoms, specific viral diagnosis is usually not required. Noroviruses appear to be readily transmissible at relatively low doses, with an infectious dose even as low as 10-100 viruses and viral shedding can occur at extremely high levels up to >106 viruses/ml. Patients with symptoms consistent with norovirus gastroenteritis are placed on contact precautions or droplet precautions in case of vomiting. Hand hygiene is the most important means of preventing the spread of infection. Disinfectants with efficacy against noroviruses must be used. Norovirus gastroenteritis is usually self-limiting and is treated with supportive measures. In immunocompromised patients a reduction of immunosuppressive therapy should be considered in severe cases. © Springer-Verlag 2014.