How long is norovirus contagious?

A person with norovirus is most contagious while symptomatic and for at least 48 hours after symptoms resolve. Some people can shed the virus in stool for up to two weeks, though they are less contagious during this period.

Does hand sanitizer kill norovirus?

Alcohol-based hand sanitizers are not very effective against norovirus because the virus lacks a lipid envelope. Washing hands thoroughly with soap and water for at least 20 seconds is the best way to remove the virus.

Can you get norovirus more than once?

Yes, immunity to norovirus is short-lived (lasting only a few months) and there are many different strains. A person can be infected multiple times throughout their life.

InfectiousICD-10: A08.1Causes approximately 685 million cases of gastroenteritis worldwide per year

Norovirus Infection

Also known as: Stomach Flu, Winter Vomiting Bug, Norwalk Virus

Norovirus is a highly contagious virus that causes acute gastroenteritis, leading to sudden onset of vomiting, diarrhea, and stomach cramps. It is the leading cause of foodborne illness outbreaks worldwide and is particularly common in closed settings such as cruise ships, schools, and nursing homes. Most people recover within 1–3 days, but dehydration can be a serious concern in young children, older adults, and immunocompromised individuals.

Symptoms

Sudden onset of nausea and vomiting

Watery diarrhea (non-bloody)

Abdominal cramps and pain

Low-grade fever

Headache

Body aches

Fatigue

Causes

Norovirus (Caliciviridae family)
Fecal-oral transmission through contaminated food, water, or surfaces
Person-to-person spread via contact or aerosolized vomit particles

Risk Factors

Being in close-contact environments (cruise ships, dormitories, nursing homes)
Eating contaminated food, especially raw shellfish
Contact with an infected person
Young children and older adults
Immunocompromised individuals

Diagnosis

Clinical diagnosis based on symptoms and outbreak context
RT-PCR testing of stool samples (most sensitive)
Rapid antigen testing (less sensitive but faster)

Treatment

Oral rehydration therapy to prevent and treat dehydration
IV fluids for severe dehydration
Rest and gradual return to normal diet
No specific antiviral medication available
Antiemetics (ondansetron) for severe vomiting if needed

Prevention

Frequent and thorough handwashing with soap and water (hand sanitizer is less effective)
Disinfect contaminated surfaces with bleach-based products
Wash fruits and vegetables and cook shellfish thoroughly
Stay home for at least 48 hours after symptoms resolve
Avoid preparing food for others while symptomatic

When to See a Doctor

Signs of dehydration (dry mouth, decreased urination, dizziness)
Vomiting or diarrhea lasting more than 3 days
High fever or bloody stools
Symptoms in an infant, elderly person, or immunocompromised individual

Frequently Asked Questions

Related Conditions

Rotavirus Infection

Infectious

Food Poisoning

Infectious

Gastroenteritis (Stomach Flu)

Digestive

Nausea and Vomiting

Digestive

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