Definition
Norovirus infection is a highly contagious viral infection causing gastroenteritis, with primary symptoms including diarrhea, vomiting, nausea, and abdominal pain. Norovirus is the leading cause of viral gastroenteritis worldwide.

Pathogenesis
The virus is transmitted through contaminated food or water, contact with contaminated surfaces, or person-to-person spread. Norovirus is resistant to common cleaning and disinfection methods, making it particularly challenging to control.

Diagnosis
Diagnosis is primarily based on clinical symptoms and their rapid onset in outbreak settings. Laboratory tests, such as detection of viral RNA in stool via PCR, confirm the infection.

Treatment
There is no specific treatment for Norovirus infection. Management is supportive and includes:

  • Hydration: Addressing dehydration with oral or intravenous electrolyte solutions.
  • Symptom relief: Easily digestible foods and medications to reduce fever or nausea, if necessary.

Prevention:

  • Frequent and thorough handwashing with soap and water.
  • Cleaning and disinfecting surfaces with bleach or effective disinfectants.
  • Avoiding consumption of contaminated food or water.

Norovirus infection usually resolves within 1-3 days but can be severe in young children, the elderly, and immunocompromised individuals. Prompt prevention and supportive care are essential to reduce spread and complications.


Key figures: Incubation is 12 to 48 hours. As few as 10 to 100 viral particles are enough to cause infection. The virus survives temperatures up to 60 degrees and chlorine around 10 ppm, and is shed for up to 2 weeks after symptoms resolve.

Bloody diarrhoea with fever makes a bacterial cause such as salmonellosis more likely, while recent antibiotic use raises the possibility of Clostridioides difficile.

Frequently asked questions

Symptoms usually begin 12 to 48 hours after exposure and last 1 to 3 days. The virus continues to be shed for up to 2 weeks after symptoms resolve, which is why hand hygiene matters well beyond the illness itself. As few as 10 to 100 viral particles are enough to infect.

Poorly. Alcohol based gels are much less effective against norovirus than against most bacteria, because the virus has no lipid envelope. Washing with soap and running water is what removes it. Surfaces need a chlorine based disinfectant; the virus tolerates temperatures up to 60 degrees and chlorine around 10 ppm.

There is no specific antiviral treatment and none is needed in most cases. Management is rehydration with fluids and electrolytes in small frequent amounts, with intravenous fluids only if dehydration is significant or vomiting prevents oral intake. Antibiotics have no role in a viral infection.

Sources


Content last updated: September 2026 (22/09/2026).