Government data reveals a significant increase in cases of severe gastroenteritis across parts of the United States this winter.

The Centers for Disease Control and Prevention (CDC) reports 91 norovirus outbreaks during the week of December 5th, a rise from 69 outbreaks the previous week.

This surpasses the previous highest number of outbreaks reported during the first week of December in recent years, which was 65.

Norovirus infection is characterized by the abrupt onset of vomiting and diarrhea. Outbreaks frequently occur in environments with close contact, such as cruise ships, nursing homes, jails, schools, and other congregate settings.

Key facts about the virus are outlined below.

What is norovirus?

According to the CDC, norovirus is the leading cause of foodborne illness in the United States, accounting for 58% of such infections annually.

Norovirus infections are caused by a group of easily transmissible viruses; as few as 10 viral particles can cause illness.

Approximately 2,500 norovirus outbreaks are reported yearly in the United States. While outbreaks can occur throughout the year, they are most prevalent from November to April.

In addition to vomiting and diarrhea, common symptoms include nausea, stomach cramps, body aches, headache, and fever.

How do you get it?

Most norovirus outbreaks result from person-to-person transmission, often through the sharing of food or utensils. The virus can also spread via contaminated food, water, or surfaces.

How long do you stay sick?

Norovirus illness typically begins suddenly, with symptoms appearing 12 to 48 hours after exposure. Most individuals recover fully within one to three days.

Despite this, norovirus causes an estimated 19 to 21 million illnesses, 900 deaths, and 109,000 hospitalizations annually in the United States. Emergency department visits related to norovirus total around 465,000 each year, with young children and adults over 65 most affected.

Who’s at risk?

Individuals of all ages are susceptible to norovirus infection. However, young children, older adults, and those with compromised immune systems are at higher risk, primarily due to the potential for dehydration from vomiting and diarrhea.

There is no specific medication to treat norovirus. Rehydration with water and other fluids (excluding coffee, tea, and alcohol) is recommended.

Medical attention should be sought for any signs of dehydration, such as decreased urination, dry mouth and throat, and dizziness upon standing. Dehydrated children may exhibit unusual sleepiness or fussiness and cry with little or no tears.

How can I protect myself?

Frequent and thorough handwashing is crucial, especially during the winter months. Wash hands with soap and warm water for 20 seconds before eating.

Cleaning surfaces with household disinfectants is also recommended.