Annual Probability of Getting Norovirus

Norovirus is the leading cause of foodborne illness in the United States, causing approximately 19-21 million illnesses each year (about 6% of the population). It results in about 109,000 hospitalizations and 900 deaths annually, primarily among young children and the elderly.

Norovirus is extremely contagious, with as few as 18 viral particles sufficient to cause infection. It spreads through contaminated food (particularly leafy greens, shellfish, and ready-to-eat foods), contaminated water, contaminated surfaces, and direct person-to-person contact. The virus can survive on surfaces for weeks and is resistant to many common disinfectants (bleach-based cleaners are most effective).

Symptoms include sudden onset of nausea, vomiting, diarrhea, and stomach cramps, typically lasting 1-3 days. While usually self-limiting, dehydration can be dangerous for young children, the elderly, and immunocompromised individuals. There is no vaccine currently available, though several candidates are in development. The most effective prevention measures include thorough hand washing (hand sanitizer is less effective against norovirus), proper food handling, cleaning contaminated surfaces with bleach solution, and staying home for 48 hours after symptoms resolve.