Is Unexplained Childhood Hepatitis Related to COVID-19? We’ve compiled the 6 questions parents are most concerned about

The recent news of “more than 100 cases of unexplained childhood hepatitis reported in many countries” has drawn attention and captured the hearts of many parents.

At least 12 countries around the world have reported nearly 200 cases, according to the latest WHO and European Centre for Disease Control tallies as of April 26.

Japan reported its first suspected case in Asia on April 26, and today the United States reported its first unexplained childhood death from hepatitis.

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Parents are “talking about the discoloration of hepatitis”, will “hepatitis of unknown cause” be transmitted to children? Is there any danger in the country? There is also a lot of “information” and “theory” circulating on the Internet, and the information is complicated.

This morning, the official account of the National Center for Infectious Diseases Medicine and the Department of Infectious Diseases of Huashan Hospital Affiliated to Fudan University – “Huashan Infection” published an article detailing this “unexplained hepatitis”, a national infectious disease Dr. Zhang Wenhong, director of the medical center and director of the Department of Infectious Diseases of Huashan Hospital Affiliated to Fudan University, also commented on this.

Zhang Wenhong speculates that this is related to the isolation of the new crown, children have not been exposed to the virus for a long time, and speculates that if this is the case and not caused by the new virus, then this time the unexplained hepatitis Subsequent impacts will decline, but we also need to be vigilant about unknown pathogens.

Lilac mother quickly sorted out the existing research, and shared with you a detailed analysis of the situation of “unexplained hepatitis in children” and the countermeasures we can take now.

What’s the matter with the recent emergence of “unexplained hepatitis in children” in many countries

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From the report released by the World Health Organization on April 23, we can learn that as of April 21, 2022, the WHO European Region and the Americas Region, a total of 12 countries reported at least 169 cases of acute hepatitis of unknown origin.

Case ages ranged from 1 month to 16 years.

These children presented with acute hepatitis, and most had gastrointestinal symptoms, including abdominal pain, diarrhea, and vomiting, and elevated levels of liver enzymes ( Aspartate aminotransferase (AST) or alanine aminotransferase (ALT) over 500 IU/L) and jaundice. But most cases have no fever.

The WHO report also proposed a provisional definition of “childhood hepatitis of unknown cause”:

“Children under 16 with acute hepatitis, non-A, B, C, D, E, and serum transaminases >500 IU/L since October 1, 2021 .”

As of publication, nearly 200 cases of “hepatitis of unknown origin” have been reported worldwide.

Why did the “hepatitis of unknown cause in children” appear this time, and will it reproduce the new crown pandemic?

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These unexplained hepatitis, probably are hepatitis cases with various causes that exist in different places, are temporarily classified together, not yet Confirmed to be caused by the same cause of transmission.

This “unexplained hepatitis” is not the same as the original “unexplained pneumonia”, there is a big difference.

First of all, most of the causes of pneumonia are some kind of pathogen infection. At that time, we also found a new virus in the patient through gene sequencing. This new virus is caused, and it is not certain whether there is human-to-human transmission.

The scope of hepatitis is broader, and it is not only pathogenic infection that can cause hepatitis. There are many other factors, such as autoimmune hepatitis, hepatitis caused by poisoning such as heavy metals. The killer’s portrait is very blurred.

Secondly, after the unexplained pneumonia was reported, it was concentrated in the same district of the same city, or even near a certain area, which was in line with the law of the gradual spread of pathogens.

But this “spread” of hepatitis did not follow biological laws. “Jump” is scattered around the world. Multi-country reports are related to cognitive changes. After the UK announced the situation, some countries looked at the situation in the hospital and “found that we also have it”. After the WHO officially announced a temporary diagnostic standard for unexplained hepatitis, Japan compared the standard and “we may also have it”.

Based on historical data, 5% to 30% of acute hepatitis cases are “unexplained.”

There is no evidence to say that the unexplained hepatitis will also repeat the unpleasant memories of the unexplained pneumonia, and soon the infectious disease pandemic that plagued the world. There is a high probability that it will not recur.

Is Unexplained Hepatitis in Children Linked to the COVID-19 Vaccine?

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The link between “unexplained hepatitis in children” and the COVID-19 vaccine is unclear.

A BBC report on April 26 mentions-

(Of children diagnosed with unexplained hepatitis) None of the children had been vaccinated.

The Covid vaccine is available in the UK from the age of 5, which means many children diagnosed with hepatitis are ineligible for the vaccine.

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In response, “Huashan Infection” also stated in the article “The direct correlation between the vaccine and unexplained childhood hepatitis can be ruled out”.

Is “adenovirus” the cause of “unexplained hepatitis”?

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Human adenovirus type F41 is currently the most likely cause of unexplained hepatitis identified, but remains unidentified.

The BBC notes that “about three-quarters of children tested for confirmed hepatitis have a specific adenovirus called F41 detected.” “points to adenovirus.

The United Kingdom, as the country with the most cases and the most research, after a multi-factor investigation, the British Health Safety Agency stated that human adenovirus F41 is the most likely unexplained hepatitis reason. Because of the hepatitis caused by this adenovirus infection, in addition to the jaundice of liver damage, there will also be gastrointestinal symptoms such as diarrhea and nausea.

Adenovirus is a very common virus around us. Data show that adenovirus is the most common causative agent of respiratory infection in children with fever. Adenovirus can be transmitted through the fecal-oral route and droplets.

The main manifestation of adenovirus infection is respiratory symptoms, but some serotypes may have gastrointestinal symptoms, or hepatitis as the main manifestation.

But adenovirus is not a new virus, so why are there so many cases of severe hepatitis this year, and only in children?

In this regard, Professor Zhang Wenhong also gave his judgment in the comments on the Huashan infection article——

“It is currently speculated that it is a long-term isolation of the new crown. Children have not been exposed to this virus for a long time, and sudden contact will cause relatively serious immune damage. This speculation is related to the emergence of new infectious diseases. It is consistent with the fact that disease outbreaks tend to be heavier in the early stages.”

“If this is the cause, rather than a new virus that has not been identified before, the subsequent effects of this unexplained hepatitis will gradually decline.”

Of course, there are many different voices.

Some scholars believe that the amount of adenovirus detected at present is not high, and it may just happen to be carried, but it is not the main cause of the disease. More detailed analysis will be required in the future to determine current inferences.

Is there any cases in China? is that true?

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There have been no reports of this unexplained hepatitis in China. Some of the information that you have seen on the Internet about “there are children diagnosed in China” has been officially refuted.

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However, just today, an article published by the “Huashan Infection” official account pointed out that “(the disease) still has an imported risk, and our country should make preparations earlier.”

Professor Zhang Wenhong’s comments in the article also mentioned that “We also need to be vigilant about unknown pathogens, even if the probability of this emerging infectious disease pandemic is not high.

You can stay vigilant, but don’t be overly anxious and don’t believe some online rumors.

What’s a good way to prevent it? What can parents do now?

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As the pathogenesis is still unclear, everyone should stay concerned, but not panic.

Parents can do this:

1. Know the signs and symptoms of hepatitis, and see a doctor if they appear. For example, the whites of the eyes or skin, yellow urine (jaundice), fever, unusual tiredness, loss of appetite, nausea, vomiting, diarrhea;

2. Teach children to pay attention to hand hygiene and wash their hands with hand sanitizer and water. Alcohol disinfection has limited effect on adenovirus;

3. Teach children to pay attention to other regular hygiene habits, such as try not to touch eyes, nose, mouth with unclean hands;

4. Try to avoid people with symptoms of illness;

5. If a child develops symptoms of a gastrointestinal infection such as vomiting and diarrhea, stay at home and wait at least 48 hours before taking the child to daycare and school;

Unknown origin is not uncommon in the diagnosis of diseases, and humans do not have the ability to identify the cause of a disease all at once. Many unexplained diseases may never know the result, and the answer may be found after a period of time.

Those of us who have experienced the new crown have already had the experience of facing unknown diseases. I believe that as long as we take adequate protection and respond scientifically, there is no reason to be afraid of our opponents, and the virus will eventually be defeated.


[1] https:

[2] Investigation into acute hepatitis of unknown aetiology in children in England Technical briefing 25 April 2022

[3] https:

[4] Ronan BA, Agrwal N, Carey EJ, De Petris G, Kusne S, Seville MT, Blair JE, Vikram HR. Fulminant hepatitis due to human adenovirus. Infection. 2014 Feb; 42(1):105-11. doi: 10.1007/s15010-013-0527-7. Epub 2013 Aug 24. PMID: 23979854.

[5] Multi-Country C Acute, severe hepatitis of unknown origin in children https: DON376

This article expert

Li Tongzeng

Review Specialist

Chief Physician, Department of Respiratory and Infectious Diseases, Beijing You’an Hospital


Planning: Eric, Astro

Producer: Feidi, Dali

Typography: Beautiful

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