Burden of Norovirus Illness and Outbreaks

Norovirus is the leading cause of acute gastroenteritis in all age groups in the United States.

Each year, norovirus—

• causes about 20 million cases of acute gastroenteritis, and
• contributes to about 70,000 hospitalizations and 800 deaths, mostly among young children and older adults

Across all ages, 16% of all acute gastroenteritis in the community is caused by norovirus, and 12% of acute gastroenteritis cases that get outpatient care are caused by norovirus.

People can get norovirus illness at any time during the year. But, it is most common in the winter. Also, there can be 50% more norovirus illness in years when there is a new strain of the virus going around.

Norovirus is the leading cause of severe acute gastroenteritis among U.S. children less than 5 years of age who seek medical care.

• Norovirus is responsible for nearly 1 million pediatric medical care visits annually.
• By 5 years of age, an estimated 1 in 278 children will be hospitalized; 1 in 14 will visit an emergency room, and 1 in 6 will receive outpatient care for norovirus illnesses.

Norovirus is the leading cause of foodborne illness in the United States. It is responsible for—

• 58% of domestically-acquired foodborne illnesses, and
• 50% of foodborne disease outbreaks due to known agents.

Each year, it costs about $2 billion in the United States for healthcare and lost productivity from foodborne illness caused by norovirus.

Most foodborne outbreaks of norovirus illness are caused by eating food that was contaminated by a food handler. However, widespread outbreaks of norovirus can also be caused by food, such as oysters, raspberries, and leafy greens, that were contaminated at their source.

Waterborne outbreaks of norovirus illness also occur in community settings. This is often caused by sewage contaminated wells and untreated recreational water.

For more information about the foodborne burden of norovirus illness, see the CDC Estimates of Foodborne Illness in the United States.