It’s something many people fear, especially during certain times of the year — you or a family member may have been exposed to the “stomach bug.” This may come from a note from school or daycare, a message from a coworker, or even a text from a friend you recently visited.
In many cases, the “stomach bug” refers to stomach illnesses known as gastroenteritis. Gastroenteritis is an inflammation of the stomach and intestines that can lead to nausea, vomiting, and diarrhea. Often, the cause of this condition is norovirus, a highly contagious RNA virus.
Norovirus causes an average of 19 to 21 million illnesses each year in the United States. Anyone can get norovirus, but children under the age of 5 and adults aged 65 or older are especially at risk. Most infections occur during the colder months of the year.
Norovirus Is Highly Contagious
Norovirus spreads very easily. Most infections are transmitted through person-to-person contact, especially through direct or indirect contact with infected stool or vomit.
Only a small amount of the virus is needed to infect many people. This is why it easily causes outbreaks in contained places such as cruise ships, daycare centers, and restaurants. Each year, there are about 2,500 reported norovirus outbreaks in the United States.
Norovirus Does Not Cause Flu-Like Symptoms
Norovirus is sometimes referred to as the “stomach flu,” but this is not accurate. It typically causes vomiting, abdominal cramps, and diarrhea.
Children usually experience more vomiting than diarrhea, while adults tend to have more diarrhea than vomiting. These symptoms can lead to dehydration, which may become severe.
Symptoms usually begin 1 to 2 days after infection and last for about 1 to 3 days. People are most contagious immediately after symptoms develop and remain most contagious for about 48 hours after symptoms resolve.
Some people may also experience fever, headache, and body aches, but not to the same degree as with the flu. Symptoms such as cough or high fever may suggest a condition other than norovirus.
Norovirus Can Be Life-Threatening
On average, norovirus causes 900 deaths in the United States each year, mostly among adults aged 65 and older.
Parents should closely monitor symptoms in children, especially infants, because dehydration can occur more quickly. Individuals with compromised immune systems should also be cautious.
Treatment and Care
In most cases, treatment involves bed rest and drinking adequate amounts of fluid. Even if vomiting occurs, fluids should be taken in small, frequent sips.
Fluids containing electrolytes or chicken broth are recommended. Sports drinks are often not ideal because they may contain more sugar than salt-containing rehydration solutions.
If symptoms of dehydration occur — such as dark yellow urine or a very dry mouth — medical attention should be sought immediately.
Because norovirus is caused by a virus, antibiotics are not needed. Antidiarrheal medications may help, but medical advice should be sought before using them.
Washing Your Hands Is the Best Defense
Washing hands thoroughly with soap and warm water is the most important step in preventing the spread of norovirus. Hand sanitizers do not kill norovirus.
Frequent handwashing, especially after using the bathroom and before preparing food, helps prevent transmission.
If someone in the household is infected, maintain distance where possible, wash soiled clothing and bedding thoroughly, and clean surfaces with chlorine- or bleach-based cleaners.
Additional preventive measures include:
- Washing hands before handling food
- Washing knives and cutting boards used for raw meat before using them with other foods
- Cooking meat and eggs thoroughly
- Refrigerating leftovers promptly
- Avoiding questionable foods such as oysters and other raw seafood
- Paying attention to food recalls for potentially contaminated purchases
Practicing these hygiene measures can help minimize the spread of norovirus within homes and communities.
