24-Jan-2023: Norovirus infection was confirmed in two schoolchildren in Kerala.
Norovirus is a highly contagious virus that causes acute gastroenteritis, an inflammation of the stomach and intestines.
Norovirus is transmitted through contaminated food or water, contact with infected people or surfaces, and aerosolized vomit. Norovirus is resistant to many disinfectants and can heat up to 60°C. Therefore, merely steaming food or chlorinating water does not kill the virus. It can also survive many common hand sanitisers.
Symptoms of norovirus infection include vomiting, diarrhea, nausea, abdominal pain, headache, and fever. The symptoms of norovirus infection usually last for 1-3 days.
Causes
- Virus family: Norovirus belongs to the family Caliciviridae.
- Viral structure: Norovirus is a non-enveloped, single-stranded RNA virus.
- Genogroups: Norovirus is classified into 10 genogroups, with genogroups I, II, and IV causing human infections.
Epidemiology
- Prevalence: Norovirus is the most common cause of acute gastroenteritis worldwide, responsible for approximately 685 million cases and 200,000 deaths annually.
- Outbreaks: Norovirus outbreaks are common in closed settings such as hospitals, nursing homes, schools, and cruise ships.
- Risk factors: Norovirus infection is more common in young children, older adults, and people with weakened immune systems.
Diagnosis and Treatment
- Diagnosis: Norovirus infection is diagnosed based on symptoms, and confirmed by laboratory testing of stool samples.
- Treatment: There is no specific treatment for norovirus infection, and the focus is on managing symptoms and preventing dehydration.
- Prevention: Hand hygiene, food safety practices, and cleaning and disinfection of surfaces are key measures to prevent norovirus transmission.
Public Health Impact
- Economic impact: Norovirus outbreaks can have significant economic impact, with costs estimated to be over $60 billion globally.
- Burden on healthcare system: Norovirus outbreaks can put a strain on healthcare resources, with hospitalizations and emergency room visits increasing during outbreaks.
- Control measures: Surveillance, outbreak investigation, and implementation of control measures are critical in preventing and controlling norovirus outbreaks.