What’s Causing the Hepatitis Outbreak in Kids?

You may have heard about the mysterious outbreak of hepatitis in kids, most of whom are between 4 and 10 years old. There have been over 1,000 cases reported in 35 countries. There have been cases reported in almost all states in the U.S., and the counts are growing. Experts believe that even more children have gotten sick, but that cases just haven’t been reported to authorities. 

“Hepatitis” means inflammation of the liver. Hepatitis causes liver damage that can be permanent. Sometimes hepatitis can lead to liver failure and death. 

So what’s causing this outbreak in kids? And why is this outbreak so concerning? If you have children, how worried should you be? Let’s take a look at the answers to these questions. 

What is causing this outbreak of hepatitis in kids?

One of the things that is unusual about the outbreak of hepatitis in kids is that no one knows exactly what’s causing it.

The common causes of hepatitis include: 

• Viruses

• Alcohol use

• Medications 

• Toxins

• Certain medical conditions

There are many viruses that can cause hepatitis. But in the U.S., the most common ones are the hepatitis A, hepatitis B, and hepatitis C viruses.

In this outbreak, officials think the cause may be the adenovirus, a common virus.

Among children who got sick in the U.S., 45% tested positive for adenovirus. But the numbers vary — in Alabama and Illinois — all of the children tested positive for adenovirus. Officials are quick to point out the reason for this difference is that not all the children were tested for adenovirus. That’s because healthcare providers don’t typically test for this virus since it rarely causes serious illness. 

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New studies from the U.K. suggest that two viruses may be responsible for the outbreak. One is adenovirus. The second virus may be “adeno-associated virus 2” (AAV2). AAV2 can only attack if someone is already sick with another virus.  

The new studies also suggest that children who’ve gotten sick have a harder time fighting off these viruses. 

Officials also reported that the outbreak isn’t related to the COVID-19 vaccine, as most of the kids weren’t vaccinated. 

What is adenovirus?

Adenovirus usually causes mild illnesses in kids, like:

• Gastroenteritis

• Upper respiratory tract infections

• Conjunctivitis

• Bladder infections

Adenovirus doesn’t usually cause hepatitis, especially in children who don’t have a decreased immune system. Experts believe three things must happen for children to get sick with hepatitis. They must have an adenovirus infection and then an AAV2 infection. Finally, the child must also be genetically likely to have trouble fighting off these viruses. 

Is the hepatitis outbreak in children serious?

The hepatitis outbreak in kids is worrisome because children are getting very sick, and many are developing liver failure. 

Almost all of the children needed to be admitted to the hospital. And some children have died. About 10% to 14% of the kids needed liver transplants. Data from the U.K. showed that more children needed urgent transplants in the first 3 months of 2022 than in the past 10 years combined. 

But the data from the CDC is less clear. An interim report shows that the rates of hepatitis and hospitalization for hepatitis in kids hasn’t changed over the past 3 years. The number of liver transplants hasn’t changed either. Researchers are quick to point out many reasons for this,  including incomplete data and the fact that not all cases were reported to authorities. The CDC will release more data as it becomes available. 

What are the symptoms of hepatitis in children?

Children with hepatitis typically experience:

• Jaundice (yellowing of the skin and eyes)

• Vomiting

• Loss of appetite

• Stomach pain

• Pale stools

• Dark urine

• Diarrhea

• Nausea

• Increased sleepiness

Data from the U.K. and the U.S. show that jaundice was the most common symptom in kids with hepatitis from this outbreak. Data from the World Health Organization (WHO) shows that fever wasn’t a common symptom. 

How common are hepatitis outbreaks?

Hepatitis outbreaks aren’t unheard of, but the exact numbers aren’t clear. Outbreaks of hepatitis A virus are fairly common in the U.S. Since 2016, there have been reports of over 40,000 cases of hepatitis A from outbreaks. 

Hepatitis B and C viruses also cause outbreaks from time to time. These outbreaks happen among people who are at higher risk for coming in contact with these viruses. 

What are the CDC’s recommendations regarding growing cases of hepatitis in kids?

The CDC and health officials worldwide are carefully monitoring this hepatitis outbreak in kids. Cases are still very rare. But the CDC recommends the following:

• Any child who develops jaundice should seek urgent medical attention.

• Children who develop other symptoms of hepatitis should see their healthcare provider.

• Healthcare providers should test children with hepatitis for adenovirus and report cases to authorities.

How do you prevent kids from getting sick with adenovirus?

There’s no treatment for adenovirus. So it’s also important to take steps to prevent getting sick. Adenovirus spreads from person to person through:

• Touch

• Air (when someone coughs or sneezing)

• Objects

• Contact with stool (especially diaper changes) 

Adenovirus can live on surfaces for long periods of time. The virus is also resistant to many common disinfectants, including isopropyl alcohol.

Here are the best ways to protect yourself and your family from adenovirus:

• Wash your hands with soap and water for at least 20 seconds.

• Don’t touch your eyes, nose, or mouth. 

• Avoid close contact with people who are sick.

If you or someone in your household is sick, stay home from work, school, and day care so you don’t get others sick. 

Why trust our experts?

Written by:

Patricia Pinto-Garcia, MD, MPH

Patricia Pinto-Garcia, MD, MPH, is a medical editor at GoodRx. She is a licensed, board-certified pediatrician with more than a decade of experience in academic medicine.

Reviewed by:

Sophie Vergnaud, MD

Sophie Vergnaud, MD, is the Senior Medical Director for GoodRx Health. An experienced and dedicated pulmonologist and hospitalist, she spent a decade practicing and teaching clinical medicine at academic hospitals throughout London before transitioning to a career in health education and health technology.

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