Norovirus | |
---|---|
Other names | Winter vomiting bug,[1] stomach bug |
Transmission electron micrograph of Norwalk virus. The white bar = 50 nm. | |
Specialty | Emergency medicine, pediatrics |
Symptoms | Diarrhea, vomiting, stomach pain, headache[2] |
Complications | Dehydration[2] |
Usual onset | 12 to 48 hours after exposure[2] |
Duration | 1 to 3 days[2] |
Causes | Norovirus[3] |
Diagnostic method | Based on symptoms[3] |
Prevention | Hand washing, disinfection of contaminated surfaces[4] |
Treatment | Supportive care (drinking sufficient fluids or intravenous fluids)[5] |
Frequency | 685 million cases per year[6] |
Deaths | 200,000 per year[6][7] |
Norovirus, also known as Norwalk virus and sometimes referred to as the winter vomiting disease, is the most common cause of gastroenteritis.[1][6] Infection is characterized by non-bloody diarrhea, vomiting, and stomach pain.[2][3] Fever or headaches may also occur.[2] Symptoms usually develop 12 to 48 hours after being exposed, and recovery typically occurs within one to three days.[2] Complications are uncommon, but may include dehydration, especially in the young, the old, and those with other health problems.[2]
The virus is usually spread by the fecal–oral route.[3] This may be through contaminated food or water or person-to-person contact.[3] It may also spread via contaminated surfaces or through air from the vomit of an infected person.[3] Risk factors include unsanitary food preparation and sharing close quarters.[3] Diagnosis is generally based on symptoms.[3] Confirmatory testing is not usually available but may be performed by public health agencies during outbreaks.[3]
Prevention involves proper hand washing and disinfection of contaminated surfaces.[4] There is no vaccine or specific treatment for norovirus.[4][5] Management involves supportive care such as drinking sufficient fluids or intravenous fluids.[5] Oral rehydration solutions are the preferred fluids to drink, although other drinks without caffeine or alcohol can help.[5] Alcohol-based hand sanitizers are not effective against the norovirus, according to the NHS information page on the subject;[8] this is due to norovirus being a non-enveloped virus.
Norovirus results in about 685 million cases of disease and 200,000 deaths globally a year.[6][7] It is common both in the developed and developing world.[3][9] Those under the age of five are most often affected, and in this group it results in about 50,000 deaths in the developing world.[6] Norovirus infections occur more commonly during winter months.[6] It often occurs in outbreaks, especially among those living in close quarters.[3] In the United States, it is the cause of about half of all foodborne disease outbreaks.[3] The virus is named after the city of Norwalk, Ohio, US, where an outbreak occurred in 1968.[10]