How is norovirus contagious

Some people with norovirus infection show no signs or symptoms. However, they are still contagious and can spread the virus to others.

Seek medical attention if you develop diarrhea that doesn't go away within several days. Also, call your doctor if you have severe vomiting, bloody stools, stomach pain or dehydration. Noroviruses are highly contagious and are shed in the feces of infected humans and animals.

You can get norovirus by:. Noroviruses are difficult to kill off because they can withstand hot and cold temperatures and most disinfectants. For most people, norovirus infection usually clears up within a few days and isn't life-threatening.

But in some people — especially children, older adults and people with compromised immune systems — norovirus infection can cause dehydration. Norovirus infection can cause severe dehydration, malnutrition and even death, especially in people who are older or immunocompromised, or in women who are pregnant.

Children who are dehydrated might cry with few or no tears. They might be unusually sleepy or fussy. Norovirus infection is highly contagious, and anyone can become infected more than once. To help prevent its spread:. Mayo Clinic does not endorse companies or products. Stomach flu is extremely contagious and can spread through person-to-person contact. A person can also catch it after coming into contact with contaminated water or food. Symptoms can pass within 3 days.

Several viruses can cause viral gastroenteritis. According to one article , the most common virus in the United States to cause viral gastroenteritis is currently the norovirus. This accounts for 19—21 million cases per year. This article will explain how long stomach flu is contagious for and how long the symptoms can last.

It will also explore the symptoms of stomach flu and when to contact a doctor and provide information on treatment and prevention methods. According to the Centers for Disease Control and Prevention CDC , a person with the norovirus is most contagious when they have symptoms of the illness, such as vomiting, and during the first few days after they have recovered. However, they also state that a person can be contagious for up to 2 weeks following the infection.

Consuming contaminated food or water, coming into contact with bodily fluids from a person with the norovirus, and swimming in contaminated water are all ways to catch the virus. A person with the norovirus typically does not require treatment unless they become dehydrated. Many symptoms of stomach flu only affect the digestive tract, but people can also experience symptoms in other areas of the body.

In many cases, dehydration can occur with stomach flu due to the amount of liquid lost during vomiting or diarrhea. The NIDDK warn that a person should seek treatment immediately if they experience any of the following symptoms of dehydration:. Learn how to treat dehydration here. The norovirus can survive on surfaces such as changing tables for months.

A person can also catch the virus if they come into contact with bodily fluids, such as vomit or stools, from the child. Common symptoms of stomach flu in children may include:. Parents or caregivers of children should look for the following symptoms or complaints from their children, as they can indicate dehydration. Symptoms of dehydration in infants or children include :. Although children can vomit more than adults, vomiting can often stop in children after 24 hours.

If the vomiting does not stop but does not increase significantly, the parent or caregiver should try to give the child clear liquids. They should not rush trying to give the child heavier foods.

The most common route of infection is the fecal-oral route. According to a study , symptoms of norovirus, rotavirus, and sapovirus usually show up 1 to 2 days after exposure, while it can take 4 to 5 days for people to develop symptoms of astrovirus.

Symptoms of adenovirus mostly show up 5 to 6 days after exposure , but they can take anywhere from 2 to 14 days to appear. Symptoms of the stomach flu typically last 1 to 3 days. Infections in those with higher risk may last longer.

Generally speaking, the virus is most likely to spread from the time your symptoms first appear until several days after your symptoms have gone away. Some viruses, such as rotavirus, can be transmitted before symptoms begin.

Even after your symptoms have cleared up, the virus may also still shed in your stool for several weeks. For example, norovirus can be shed in stool for 2 weeks or longer and rotavirus can be found in stool for up to 10 days. There are several types of viruses that can cause stomach flu. They include:. While anyone can get stomach flu, some people are at a higher risk of developing severe illness, including:. The risk of a stomach flu outbreak increases when large groups of people are in close contact with each other.

Examples of this include:. The viruses that cause stomach flu are present in stool and vomit. Norovirus in particular is resilient. It can survive for 2 weeks on surfaces and for 2 months or more in water. It can also withstand temperature changes and many common cleaning products.

This can make it easier to spread from one person to another. Although you may not be able to completely avoid these viruses, you can take steps to lower your risk, especially if someone in your household has a stomach virus. If you currently have stomach flu, there are things that you can do to prevent the virus from spreading to other people.

Typically, most people with stomach flu recover from their illness without having to seek medical treatment. The following home remedies can help ease the symptoms of stomach flu and prevent more serious illness. Medical treatment involves managing your symptoms and promoting hydration.

You may be given intravenous IV fluids to help replace lost fluids and electrolytes.