What Are Adenoviruses?

Adenoviruses are a group of viruses that can cause infections. Adenovirus (add-eh-noe-VY-rus) infections can happen in kids of any age, but are more common in babies and young children. Most kids have had at least one adenovirus infection before age 10.

There are many different types of adenoviruses, so people can get infected more than once. These viruses don’t have a “season” like other viruses (the flu, for example), so infections can happen at any time of the year.

What Illnesses Do Adenoviruses Cause in Kids?

Adenoviruses are common causes of fever and illnesses such as:

• colds
• pinkeye
• croup
• bronchiolitis
• pneumonia
• gastroenteritis
• bladder infection
• meningitis and encephalitis

Most infections are mild, but serious infections can happen, especially in infants and people with weak immune systems. Some types of the virus are linked to more severe disease.

What Are the Signs & Symptoms of Adenovirus?

The symptoms of adenovirus infections depend on the type of adenovirus and the part of the body affected. Symptoms similar to a common cold happen most often, such as a fever, sore throat; a congested, runny nose; and a cough.

Adenoviruses can also cause:

• eye redness and pain
• diarrhea
• vomiting
• belly pain
• frequent peeing, burning pain while peeing, blood in the urine
• headache

Is Adenovirus Contagious?

Adenovirus is highly contagious. Infections are common in close-contact settings, such as childcare centers, schools, hospitals, and summer camps.

Adenovirus can spread through droplets when someone with an infection coughs or sneezes. Fecal material (poop) can spread the infection via contaminated water, dirty diapers, and poor hand washing. Outbreaks of adenovirus at summer camps are linked to contaminated water in swimming pools and lakes.

A child might also pick up the virus by touching someone who has it. Adenoviruses can survive on surfaces for a long time. So they can spread on contaminated toys, towels, and other objects.

Symptoms usually start 2 days to 2 weeks after contact with adenovirus.

How Are Adenovirus Infections Diagnosed?

Adenovirus infection symptoms are a lot like those caused by other infections. Usually, tests aren’t needed if someone has mild symptoms. But if a person has a serious infection, doctors can test respiratory or conjunctival (eye) secretions, a stool sample, or a blood or urine sample to confirm the diagnosis.

Doctors will also test for adenovirus during suspected outbreaks. (An outbreak is when many people come down with the same symptoms.)

How Are Adenovirus Infections Treated?

Most adenovirus infections get better with treatment at home, including:

• getting plenty of rest
• drinking enough liquids
• giving acetaminophen if fevers are making your child uncomfortable 
• using a humidifier or saltwater nose drops to help kids with congestion

Babies and children with vomiting and diarrhea who can't drink enough liquids may need treatment for dehydration.

Infants (especially newborns and premature babies), people with weak immune systems, and healthy children and adults with severe adenovirus infections may need antiviral medicine and treatment in a hospital that could include IV fluids, oxygen, and breathing treatments.

How Long Do Adenovirus Infections Last?

Most adenovirus infections last from a few days to a week or two. Severe infections may last longer and cause lingering symptoms, such as a cough.

Can Adenovirus Infections Be Prevented?

To help prevent the spread of adenovirus infections, parents and other caregivers should:

• make sure kids and caregivers wash their hands well and often
• keep shared surfaces (such as countertops and toys) clean
• keep kids with infections out of daycare and school until symptoms are gone
• teach kids to sneeze and cough into shirtsleeves or tissues — not their hands

When Should I Call the Doctor?

Call your doctor if your child is sick and:

• has a high fever or one that lasts more than a few days
• has breathing problems
• is under 3 months old or has a weak immune system
• has red eyes, eye pain, or a change in vision
• has severe diarrhea, vomiting, or signs of dehydration, such as peeing less or having fewer wet diapers, a dry mouth, sunken eyes, acting tired and listless

You know your child best. If they seem very ill, call your doctor right away.