Adenovirus Infection: Symptoms and Treatment

Medically Reviewed by Poonam Sachdev on October 19, 2023
7 min read

Adenoviruses are a group of common viruses that can infect your airways and lungs, eyes, intestines, urinary tract, and nervous system. They're common causes of fever, coughs, sore throats, diarrhea, and pink eye.

The infections usually cause only mild symptoms and get better on their own in a few days. But they can be more serious in people with weak immune systems, especially children.

Adenovirus vectors

Vectors are harmless versions of viruses used in some vaccines and medical treatments. Scientists use them to deliver genetic information to your cells that helps your body mount an immune defense, which protects you against diseases. Adenoviruses are commonly used as vectors, including for some COVID-19 vaccines. The vaccines can't give you an adenovirus infection.

Adenovirus vs. coronavirus

Like adenoviruses, coronaviruses are spread from person to person and can cause similar respiratory symptoms. But they belong to different virus families and are different in other ways. Coronaviruses are less resistant to disinfectants. So adenoviruses spread more easily.

Who gets adenovirus?

Adenovirus infections happen in children more often than in adults, but anyone can get them. Most kids will have at least one type of adenovirus infection by the time they're 10. These viruses are common in places with large groups of kids, such as day care centers, schools, and summer camps.

Adults who live in close quarters like dorms or nursing facilities are at a high risk of infection.

Adenoviruses are very contagious. They can spread through a number of ways:

  • By touching an infected person or object. Your child can catch the virus when they touch the hand of someone who has it or a toy or other object held by someone who has it and then touches their mouth, nose, or eyes. It spreads quickly among children because they're more likely to put their hands on their faces and in their mouths.
  • Through the air. Adenoviruses can spread when someone who's infected coughs or sneezes. Droplets containing the virus fly into the air and land on surfaces.
  • Through poop. You can get infected when you change a diaper. You also can get sick from eating food prepared by someone who didn't wash their hands properly after going to the bathroom.
  • In water. It's possible to catch the virus in water, like in small lakes or a swimming pool, that isn't well maintained. But this doesn't happen often.

How long is adenovirus contagious?

You're most likely to give adenoviruses to others in the first few days you have symptoms. But it's possible to spread it for days or even weeks after you feel better. Adenoviruses can live on surfaces for up to 30 days.

Each type of adenovirus infection has a different set of symptoms:

  • Bronchitis: Cough, runny nose, fever, chills
  • Colds and other respiratory infections: Stuffy and runny nose, cough, sore throat, and swollen glands
  • Croup: Barking cough, trouble breathing, high-pitched sound when breathing in
  • Ear infection: Ear pain, irritability, fever
  • Pink eye (conjunctivitis): Red eyes, discharge from your eyes, tearing, feeling like there's something in your eye
  • Pneumonia: Fever, cough, trouble breathing
  • Stomach and intestinal infections: Diarrhea, vomiting, headache, fever, stomachcramps
  • Swelling of the brain and spinal cord (meningitis and encephalitis): Headache, fever, stiff neck, nausea, vomiting (this is rare)
  • Urinary tract infections: Burning and pain while urinating, frequent need to go, blood in your urine

If you think your child may have one of these viruses, check with their pediatrician. Always call the doctor if a baby under 3 months old has symptoms of an adenovirus infection.

Adenovirus conjunctivitis

Adenoviruses are the most common cause of conjunctivitis (pinkeye), though other germs can also cause it. Along with red eyes, you may notice:

  • Swollen eyelids
  • Blurred vision
  • A crust along your eyelids which can make it hard to open your eyes
  • Light sensitivity
  • A lump near one of your ears

Adenovirus rash

Rashes caused by viruses like adenovirus may look like blotches, spots, or bump. Sometimes they're itchy but not always. You might notice them first on your child's face or torso. But they can show up in other places, too. You or your child might have other symptoms like fever, tiredness, and body aches.

Adenovirus in kids

If they have symptoms at all, most kids with an adenovirus infection will have respiratory symptoms similar to those of a cold: a fever, runny or stuffy nose, or sore throat. If they also develop an ear infection, they'll have ear pain. Pinkeye symptoms are also common in children.

If the virus affects the digestive tract, they may have cramps and diarrhea. Sometimes, adenoviruses can infect the bladder. This can make it painful to pee, and you may see blood in their pee.

Adenovirus in adults

While adenovirus infections most often affect kids, adults can get them, too. As with children, symptoms are usually mild and most often affect the respiratory system.

You're more likely to get seriously sick from an adenovirus if you:

  • Have a weakened immune system due to a condition like HIV or cancer
  • Take immune-suppressing drugs
  • Have heart or lung disease
  • Have had an organ transplant
  • Are older

How long does adenovirus last?

Most of the time, adenovirus symptoms clear up within 3-5 days. But a serious infection could last weeks.

Call the doctor right away if your child has any of these symptoms:

  • Trouble breathing
  • Swelling around their eyes
  • Fever that's higher than 104 F or doesn't go away after a few days
  • Signs of dehydration, such as few tears or less wet diapers
  • They seem fussy and have trouble sleeping
  • They're less alert and active than usual

Your child's doctor may want to do a physical exam and possibly one or more of these tests to see if a virus or bacteria caused the infection:

  • Blood test: A nurse will take a sample of your child's blood from a vein in their arm.
  • Urine test: Your child will pee in a cup the nurse gives you.
  • Swab test: A nurse will use a cotton swab to get a sample of mucus from your child's nose.
  • Stool test: You'll collect a sample of your child's poop at home and bring it to the doctor's office.
  • Chest X-ray: Your child will lie still while a technician uses a small amount of radiation to take pictures of the inside of their chest. This will give your child's doctor a closer look at their heart and lungs.

Antibiotics won't help adenovirus infections because these drugs only kill bacteria. Children often get over the illness on their own within a few days. Some infections, like pink eye or pneumonia, can last a week or more.

Kids with a weak immune system may need treatment in the hospital to help them recover.

You can do some things to help your child feel better:

  • Give plenty of liquids. Kids lose fluids from fever, vomiting, and diarrhea. They can get dehydrated. Water or 100% fruit juice are the best choices to keep kids hydrated. You might also try a children's solution that has electrolytes.
  • Clear congestion. Help your child blow their nose often. For an infant, put a few drops of saline spray or drops into their nose. Then suction out mucus with a bulb syringe.
  • Turn on a cool-mist humidifier. The moisture will loosen congestion and help your child breathe more easily.
  • Bring down a fever. Ask your doctor if you can give your child acetaminophen (Tylenol) or ibuprofen (Motrin) to relieve aches and fever. Don't give children products that contain aspirin, which can lead to a rare but serious condition called Reye syndrome.

To help keep your child from getting sick:

  • Try to keep your child away from anyone you know is sick.
  • Wash your child's hands—and yours—often during the day and especially before meals. Use an alcohol-based hand sanitizer if you don't have soap and water nearby.
  • Clean surfaces, like sinks and counters, to get rid of germs.
  • Don't let them swim in pools that aren't well maintained.
  • Regularly clean toys and other objects they often touch.
  • Discourage them from sharing cups and utensils with others.

Keep your child home when they're sick to avoid spreading adenoviruses to others. Tell them to cover their nose and mouth whenever they sneeze or cough.

Adenovirus vaccine

No adenovirus vaccine is yet available to the public. There is a vaccine, but it's given only to members of the military who are at an increased risk of infection. The vaccine uses a live virus, so those who get it could spread the virus to others. We need more research to see whether the vaccine might be safe for general use.

Adenoviruses are a group of viruses that often infect children. Most of the time, they go away on their own in a few days. But call your doctor if your child's symptoms seem serious or last a long time.

How serious is adenovirus?

Adenovirus infections are almost always mild. But sometimes they lead to serious problems like pneumonia. In rare cases, a virus can get past the immune system and affect the brain, heart, or liver. Serious illness is more likely in people with weakened immune systems.

Is adenovirus the same as respiratory syncytial virus (RSV)?

Adenoviruses and RSV can cause similar symptoms, like coughing, fever, and runny nose. Like adenoviruses, RSV is common among children. But RSV doesn't belong to the adenovirus family. It's possible to have RSV and an adenovirus infection at the same time. The general public can get vaccines for RSV but not for adenovirus.