Claim: Norovirus causes the gastrointestinal tract to inflame.

Norovirus , sometimes referred to as the winter vomiting bug in the UK and Ireland , is the most common cause of viral gastroenteritis in humans . It affects people of all ages . The virus is transmitted by fecally contaminated food or water , by person-to-person contact , and via aerosolization of vomited virus and subsequent contamination of surfaces . Annually , norovirus is associated with 906,000 outpatient visits in industrialized countries , with 64,200 inpatient hospitalizations . In developing countries , it is associated with 1.1 million hospitalizations , with an estimated 218,000 deaths .   Norovirus infection is characterized by nausea , vomiting , watery diarrhea , abdominal pain , and in some cases , loss of taste . A person usually develops symptoms of gastroenteritis 12 to 48 hours after being exposed to norovirus . General lethargy , weakness , muscle aches , headaches , and low-grade fevers may occur . The disease is usually self-limiting , and severe illness is rare . Although having norovirus can be unpleasant , it is not usually dangerous and most who contract it make a full recovery within two to three days . On surfaces , norovirus is rapidly inactivated by either sufficient heating or by chlorine-based disinfectants and polyquaternary amines , but the virus is less susceptible to alcohols and detergents .   After infection , immunity to the same strain of the virus -- the genotype -- protects against reinfection for between 4.1 -LRB- 95 % confidence interval -LSB- CI -RSB- 3.2 -- 5.1 -RRB- to 8.7 -LRB- 95 % CI 6.8 -- 11.3 -RRB- years . This immunity does not fully protect against infection with the other diverse genotypes of the virus .   Outbreaks of norovirus infection often occur in closed or semiclosed communities , such as long-term care facilities , overnight camps , hospitals , schools , prisons , clubs , dormitories , and cruise ships , where the infection spreads very rapidly either by person-to-person transmission or through contaminated food . Many norovirus outbreaks have been traced to food that was handled by one infected person .   The genus name Norovirus is derived from Norwalk virus , the only species of the genus . The species causes approximately 90 % of epidemic nonbacterial outbreaks of gastroenteritis around the world , and may be responsible for 50 % of all foodborne outbreaks of gastroenteritis in the United States .