Rotavirus is a type of germ called a virus. Illness from the virus is called a rotavirus infection. Rotavirus infections most often affect children under age 5. An infection causes watery stools, called diarrhea.

Rotavirus spreads easily. Cleaning household surfaces and hand-washing can slow the spread of disease. A rotavirus vaccine can help prevent infection and lessen how bad the illness gets.

Diarrhea from a rotavirus infection gets better over time but may last up to a week. Most rotavirus infections can be treated at home with rest and plenty of fluids. More-serious cases may mean a person needs to stay in the hospital.

In adults, rotavirus infection doesn’t tend to causes symptoms or causes mild symptoms.

In children and others, symptoms often start within two days of exposure to the virus. Symptoms include:

• Fever and vomiting. These are often the first symptoms people have, but they tend to improve by the second day.
• Diarrhea. This symptom can last a few days to a week. It may take a few weeks for stools to return to their typical appearance and patterns.

Children

Call your child's healthcare professional if your child has any of the following:

• Diarrhea for more than 24 hours.
• Fever of 102 degrees Fahrenheit (38.9 degrees Celsius) or higher.
• Fever of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher in children under 3 months old.
• Frequent vomiting.
• Intense pain in the stomach or rectum.
• Black or tarry stools, or stools with blood or pus.
• Symptoms of serious fluid loss, called dehydration.

In children, symptoms of dehydration may include:

• Excessive thirst or dry mouth.
• Crying without tears.
• Low energy.
• Little urination, or no wet diapers for three or more hours.
• Sunken eyes or cheeks.
• Sunken soft spot on baby's skull.
• Loss of skin elasticity.

Adults

Call your healthcare professional if you have:

• Diarrhea for more than two days.
• Fever of 102 degrees Fahrenheit (38.9 degrees Celsius) or higher.
• Frequent vomiting.
• Intense pain in the stomach or rectum.
• Six or more stools in 24 hours.
• Black or tarry stools, or stools with blood or pus.
• Symptoms of serious fluid loss, called dehydration.

Symptoms of dehydration include:

• Excessive thirst or dry mouth.
• Less urination than typical or dark urine.
• Extreme tiredness.
• Sunken eyes or cheeks.
• Loss of skin elasticity.
• Lightheadedness or fainting.

Rotavirus passes from one person to another because it is present in stool. If a person has a rotavirus infection, the virus is in stools at least two days before symptoms start. It can be present in stools up to 10 days after symptoms start.

Unwashed hands can carry the virus and pass the virus to any touched object, such as a toy, doorknob or toilet handle. This means that even the smallest contact with stools — even contact that's not visible — can spread the virus.

The virus can then pass from hands or objects to the mouth.

It's possible to get a rotavirus more than once, but the first infection usually has the worst symptoms.

Rotavirus infections are most common in children under 5 years old. More-serious illness occurs in children under 3 years old. Infants under 3 months old usually don't get rotavirus infections.

Because the disease spreads easily, outbreaks may occur in child-care settings or children's hospitals.

In the United States, the risk of rotavirus is highest in winter and spring.

Dehydration

The most common complication of a rotavirus infection is dehydration. This is a large loss of water and important salts and minerals. Both vomiting and diarrhea can cause dehydration.

Young children may not be able to take in as many fluids as they've lost. This is particularly true for those with weakened immune systems.

In a serious case of dehydration, fluids are added directly to the bloodstream in the hospital. If not treated, dehydration can cause organ damage, other serious disease and death.

Intussusception

A rare complication of a rotavirus infection is intussusception (in-tuh-suh-SEP-shun). This is when one part of the intestine slides into another part of the intestine, like a telescope folded up. This blocks the intestine and cuts off blood flow to that section of the intestine.

Symptoms include intense stomach pain, vomiting and bloody stools. This complication needs immediate medical care.

In most cases of intussusception, the cause is not known.

To prevent the spread of the virus, wash your hands with soap and water:

• After using the toilet.
• After changing a diaper or helping a child use the toilet.
• Before and after eating.

If someone in your family has a rotavirus infection, clean surfaces more often. Use soap and water to clean shared objects, such as toys. Use soap and water to clean things that are touched often, such as diaper bins, doorknobs and toilet handles.

Use an antiviral cleaning product or bleach solution to disinfect surfaces. You can make a bleach solution with 1/3 cup (79 milliliters) bleach and 1 gallon (3.8 liters) of room-temperature water.

Vaccination

Rotavirus vaccine for infants is part of the childhood vaccine schedule. There are two options:

• RV5 vaccine (RotaTeq). This vaccine is given by mouth in three doses to infants at 2, 4 and 6 months.

• RV1 vaccine (Rotarix). This vaccine is a liquid given in two doses to infants at ages 2 and 4 months.

Children can get the vaccine until they turn 8 months old. There is a catch-up schedule for the vaccines.

The vaccines are considered 74% effective or better in preventing rotavirus infection. They are 96% or better for preventing serious illness. Effectiveness of the vaccine lasts for the first 2 to 3 years of life.

Intussusception is a rare complication of the vaccines. In the United States, there is an estimated one case for every 20,000 to 100,000 vaccinations.

Symptoms of intussusception include intense stomach pain, vomiting and bloody stools. This complication needs immediate medical care.

A diagnosis of rotavirus infection is based on:

• Symptoms.
• Age of the child.
• The time of year.
• Information about close contacts who have rotavirus.

Your healthcare professional may take a stool sample for lab testing to confirm the diagnosis.

There is no medicine to treat rotavirus infection. Anti-diarrheal medicines are not recommended for children.

Diarrhea from a rotavirus infection gradually improves but may last up to a week.

Preventing or treating dehydration is the most important treatment goal. Drinks designed to keep children hydrated include Enfalyte, Pedialyte and others. These provide water and important salts and minerals.

Use them as directed, and ask your healthcare professional any questions about using these products.

Serious dehydration may mean a hospital stay to get fluids directly into the bloodstream.

A baby can continue regular breastfeeding or drinking formula as usual. Some infants who drink formula may benefit from a lactose-free formula.

Children can eat when they feel ready. Bland foods that may help include:

• Whole-grain breads or crackers.
• Lean meats.
• Yogurt.
• Fruits and vegetables.

Avoid the following:

• Fatty foods.
• Fruit juices.
• Drinks with added sugar.
• Sweets and desserts.

You'll likely see your primary care professional. If there are serious complications, you may see a specialist in digestive conditions, called a gastroenterologist.

What you can do

Preparing a list of questions will help you make the most of your time during your appointment. Some questions you might want to ask the healthcare team include:

• What's the likely cause of these symptoms? Are there other possible causes?
• Is there a need for tests?
• What's the best treatment approach? Are there other options?
• Is there a need to take any medicine?
• How can I ease the symptoms?

What to expect from your doctor

Some questions your healthcare professional may ask include:

• When did symptoms begin?
• Have the symptoms been continuous, or do they come and go?
• How bad are the symptoms?
• Does anything seem to improve the symptoms?
• What, if anything, appears to worsen the symptoms?