Pediatric hepatitis – what you need to know!

Why was the CDC health alert about the rare cluster of pediatric hepatitis cases an important announcement?

  • The immediate impact has been clinicians and public health authorities being more
    alert to symptoms of hepatitis in young children, and screening them for
    adenovirus infection.
  • The indirect impact and a long-term message is the reminder to all that public health
    surveillance along with timely and appropriate health alerts are important
    measures in safeguarding the nation from health threats. 
    • Historically, these scares have ranged from an outbreak of respiratory illness due to a novel coronavirus (Jan. 2020) to an increase in human rabies cases linked to bats in the United States (Jan. 2022), the role of THC products in lung injury associated with
      vaping (Sept. 2019), or most recently, significant liver injury (hepatitis) of
      unknown origin (April 2022). 

The first five hepatitis cases admitted in October 2021 to a children’s hospital in Alabama, showed significant liver injury, including some with liver failure. Since then, additional cases have been identified in other states, including in Alabama, and two in North Carolina. 

There are a couple of things immediately unusual about these hepatitis cases. 

  1. They all tested negative for the “usual” causes of hepatitis, including Hepatitis viruses A, B, and C, and other causes such as autoimmune hepatitis, Wilson disease, bacteremia (presence of bacteria in the blood), urinary tract infections, and SARS-CoV-2 infection. Instead, they all tested positive for adenovirus, more commonly known for respiratory infections.
  2. These children were all previously healthy, whereas until now, adenoviral hepatitis was typically seen in immunocompromised children.

Why would adenovirus infections, mostly known for “pink eye” or colds, cause significant liver injury in some children?

  • We don’t know, yet.
    • However, we have the nation’s public health experts analyzing and interpreting these hepatitis cases, with surveillance seeking any additional cases.

In addition to “pink eye,” aka conjunctivitis, adenoviruses can cause

  • pneumonia (difficulty breathing)
  • acute gastroenteritis (nausea, diarrhea, vomiting, and stomach pain)
  • the common cold
  • flu-like symptoms, including fever and sore throat
  • Uncommon diseases include
    • cystitis (bladder infection),
    • myocarditis (inflammation of heart muscle),
    • neurologic diseases (including febrile seizures, encephalitis, etc.) and
    • hepatitis (inflammation of the liver).

As to why a virus can cause so many different manifestations of disease, the answer lies in the 68 different serotypes of adenoviruses that can infect humans.

  • A serotype is a virus that is different enough to elicit different antibodies by our immune system.
    • These antibodies are different enough to react specifically with the unique adenovirus type.
  • These serotypes are also wired differently enough that they can cause the variety in diseases that we see with adenovirus infection.
  • Adenovirus serotype 41 is currently being investigated as the cause of concern.
    • In its usual mode, serotype 41 causes gastroenteritis in children.

Adenoviruses can often be recovered from tonsils or adenoids of healthy children.

After setting up an infection in people, adenoviruses will periodically replicate from their hideout in the throat and/or gut, and shed (release) newly created viruses, which can spread to other people.

Like many other respiratory viruses, including Influenza virus and SARS-CoV-2, adenoviruses can be spread

  1. from close contact with infected, asymptomatic individuals;
  2. by coughs and sneezes;
  3. by touching your eyes, nose, or mouth after touching fomites – which are inanimate objects like doorknobs, elevator push buttons, desktops, etc., contaminated with viruses.
  4. In addition, adenoviruses can spread when hands contaminated with feces that carry adenoviruses, come in contact with a person’s eyes, nose, or mouth.
  5. Although not common, adenoviruses can also be spread by swimming in inadequately chlorinated swimming pools.

There are several viruses with the potential to affect human health.

What’s common to all viruses is the fact that they are strict parasites and essentially come to a halt if deprived of additional human bodies they can infect.

  • Even though adenoviruses can cause asymptomatic infections, are ubiquitous, and once it infects, may hang around in our tissues for days or even, years, there are still some measures that will stop adenoviruses from spreading through the population. 

The last two years have certainly highlighted the varied ways in which we can engage in prevention, a key measure being adequate hand hygiene.

  • Whether washed with soap and water or cleaned with an alcohol-based sanitizer, clean hands protect us from a variety of infections – bacterial, viral, fungal, and parasitic.
    • Something to keep in mind as we re-enter the world of close contact with others.

The images in this post are from the Centers for Disease Control & Prevention (CDC) website or created by me.

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