Shanghai, Beijing, and Hangzhou have entered a critical period in the fight against the epidemic, and there is nervous news from overseas:
Multiple countries reported acute hepatitis of unknown cause in children, mainly in Europe. The latest news on the 25th showed that a very similar case of unknown cause also occurred in Japan. hepatitis.
Image source: CCTV.com
Global prevalence of unexplained hepatitis
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Beginning in October 2021, a children’s hospital in Alabama, USA, has found 9 children with acute hepatitis The patient, routine hepatitis virus test was negative. The specific causes of hepatitis were then analyzed until more serious cases emerged in Europe.
From March 31, 2022, acute hepatitis of unknown cause in children is gradually being reported across the UK. The UK first notified WHO of the situation on 5 April.
After April 8, similar reports began to appear in Ireland, Spain and other places in Europe.
On April 15, WHO made its first public reference to hepatitis in the UK.
On April 23, the WHO announced that at least 169 cases of acute hepatitis of unknown etiology in children had been identified in 12 countries, including 114 cases reported in the United Kingdom and 13 cases in Spain. For example, there are 12 cases in Israel, 9 cases in the United States, 6 cases in Denmark, 5 cases in Ireland, 4 cases each in the Netherlands and Italy, 2 cases each in Norway and France, and 1 case each in Romania and Belgium. The announcement also gave the WHO-recommended diagnostic criteria for unexplained hepatitis.
A case of highly similar hepatitis of unknown origin was reported for the first time in Japan.
Is Unexplained Hepatitis Reproducing the COVID-19 Pandemic?
In many of the current cases, hepatitis did not spread rapidly from the UK In Japan, it has not yet been confirmed that it is caused by the transmission of the same cause.
The total number of cases is less than 200, which is not significant in the face of the large global population base. Why did the hepatitis cause such an uproar this time? Not only the dozen or so countries that have been affected, but also China, which has no reported cases, is extremely concerned.
The descriptions of “unknown reason” and “appearance in many countries” bring our memory back to more than 2 years ago, at the beginning of the new crown pneumonia epidemic at the end of 2019, and we also saw it. similar words.
Unknown origin is actually not uncommon in disease diagnosis. Humans do not have the ability to identify the cause of disease at once. Many unexplained diseases may never know the result, and the answer may be found after a period of time.
In the early days of the new crown epidemic, we also called the unrecognized situation as pneumonia of unknown cause.
Today, this unexplained hepatitis is quite different from the original unexplained pneumonia.
First of all, most of the causes of pneumonia are caused by a certain pathogen. Virus, the murderer is about to come out, but it is impossible to ensure that this new virus is caused in a short time, and it is not certain whether there is a phenomenon of human-to-human transmission.
The scope of hepatitis is broader, not only pathogen infection 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 concentrated in 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. “Jumps” are 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”.
Now there are more than 100 cases of unexplained hepatitis. Hepatitis cases, which have been roughly classified together for the time being, are not the “quick spread of hepatitis from the UK to Japan” as many people say.
Based on historical data, 5% to 30% of acute hepatitis cases are “unexplained”.
Now there is no evidence to say that unexplained hepatitis will also repeat the process from unexplained pneumonia to the infectious disease pandemic that plagued the world soon, those unpleasant memories There is a high probability that it will not recur.
Medical experts say this about unexplained hepatitis< /p>
Human adenovirus type F41 is currently the most likely cause of unexplained hepatitis, but Still can’t confirm.
This unexplained hepatitis is unlikely to be the start of a pandemic, but it has also caught the attention of the World Health Organization. The main reason is the concentrated appearance in a short period of time, which is still a bit unusual, unlike the usual sporadic cases of acute unexplained hepatitis in children.
The most cases areThe country with the most research is the United Kingdom. A focused analysis of these cases in the UK can also help us understand the process of finding the cause of hepatitis.
When the British found that acute hepatitis in children was concentrated, they first followed the procedure to rule out the most common cause of hepatitis, that is, various hepatitis viruses.
Many viral infections can cause mild or severe liver damage. There is a type of virus that specifically attacks the liver, collectively known as “hepatitis viruses”. Includes hepatitis A, B, C, D, and E viruses. The most common cause of hepatitis is this viral infection.
After ruling out the above hepatitis viruses, continue to pay attention to the toxicological investigation. Blood metal analysis has been completed in some cases, and testing of key liver poisons including acetaminophen and aflatoxin has also been carried out. There have been no positive reports yet.
And then there is the investigation of autoimmune hepatitis. At present, autoimmune hepatitis is indirectly ruled out by a negative blood autoantibody test.
Finally put the suspect back on the virus. In addition to specialized hepatitis viruses, other viruses are sometimes responsible for liver damage.
Image source: References
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The latest report on the 25th, among the various virus tests that have been done. The Adenovirus on the far left is the most commonly detected virus in patients. (green: tested positive, blue: tested negative, yellow: results pending, orange: not tested)
Adenovirus is all around us Very common virus. Data show that the most common causative agent of respiratory tract infection in children with fever is adenovirus. Adenovirus can be transmitted by the fecal-oral route and by droplets.
The main manifestation of adenovirus infection is respiratory symptoms, but some serotypes may have gastrointestinal symptoms, or hepatitis as the main manifestation.
The UK has performed adenovirus whole-genome sequencing in 11 patients with adenovirus infection, with preference given to patients with severe disease. It was found that all 11 cases were human adenovirus F41 (HAdV-F41) among adenoviruses. Previous cases in the United States had the same result.
After this series of tests and exclusions, the UK Health Safety Authority said that human adenovirus F41 was the most likely cause of unexplained hepatitis.
Hepatitis caused by this adenovirus infection, in addition to the jaundice of liver damage, also has gastrointestinal symptoms such as diarrhea and nausea .
Of course, there are also some skeptical voices. Some scholars believe that the number of adenoviruses 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.
Paradoxically high incidence of adenoviral hepatitis
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Adenovirus infections are frequent, mainly mild respiratory infections. It is not surprising that adenovirus hepatitis occurs in a few cases, and cases have also appeared in previous years. But why did this concentration appear?
Current speculation is mainly the “immune debt” theory.
There are two ways to acquire immunity after human beings are born. One is passive immunity obtained from natural infection/recovery, and the other is active immunity obtained through vaccination.
There is no vaccine for adenovirus, so more immunity is built upon exposure to the virus. Because of the new crown epidemic, children stay at home more and rarely contact other children, and there is a problem of immunization debt. That is, chronic low exposure to a specific pathogen leads to insufficient protective immunity, thereby making a larger proportion of the population susceptible to the disease.
Image source: References
Reported adenovirus infections. We can see the obvious trough of infection in 2020 and 2021, which is the safest period for children not to touch each other. But as exposure increased, infections rebounded significantly. In particular, adenovirus infections in British children aged 1 to 4 years showed a peak not seen in previous years. 1 to 4 years old is also the age group of children with unexplained hepatitis this time.
More adenovirus infections may lead to a small number of adenovirus-induced hepatitis.
Hepatitis of unknown origin with no detectable adenovirus
What’s the matter again
It seems that adenovirus is the most plausible explanation at the moment, but what about unexplained hepatitis for which adenovirus is not detected?
In the UK, there are a small number of undetected hepatitis of unknown origin with no detectable adenovirus, and cases reported in other countries are more negative for adenovirus.
This is mainly related to the current WHO definition of unexplained hepatitis. In a report released by the World Health Organization on the 23rd, the provisional definition criteria are as follows:
Acute hepatitis since October 1, 2021 , non-hepatitis A, hepatitis B, hepatitis C, hepatitis D, hepatitis E, and serum aminotransferase> 500 IU/L children under 16 years old.
This is obviously a rougher criterion, hepatitis caused by other viral infections that were excluded from the UK study, hepatitis with no detectable toxicants , less typical autoimmune hepatitis, may meet this rough standard, and temporarily enter the category of unexplained hepatitis.
For example, the unexplained hepatitis reported in Israel was found to be autoimmune hepatitis during further analysis.
If the standard is still this rough requirement in the future, more cases will be reported. The underlying reasons behind them should be mixed.
These unexplained hepatitis rumors are not credible< /p>
Rumor: Hepatitis linked to adenovirus vaccine
Adenovirus vaccine does not carry adenovirus Infect.
It is speculated that the main cause of hepatitis is adenovirus, so some people think of the new crown vaccine. There are indeed people in China and the UK who have been vaccinated against the adenovirus route.
However, the adenovirus route vaccine only relies on the partial structure of adenovirus that has genetic defects and cannot continue to replicate (and it is not a human adenovirus). Adenovirus vaccine, adenovirus infection, or similar adenovirus infection leads to liver damage.
The adenovirus route vaccine has been used for many years, and there has never been a report of adenovirus infection before. This time, none of the patients in the UK have been vaccinated against the new coronavirus adenovirus route because of their age.
Rumor: Unexplained hepatitis caused by COVID-19
There are indeed rare reports of liver damage caused by hepatitis caused by the new coronavirus infection. However, among the unexplained hepatitis patients reported in this report, it is not the impact of the new coronavirus.
Take the British patient with the most abundant data as an example. Among the 61 patients who were clearly reported to have been admitted to the hospital and tested for the new coronavirus, only 10 were positive for the new coronavirus, less than 1. /6. This proportion happens to be the proportion of Covid-19 positives in the UK children’s community, so it cannot be assumed that Covid-19 is directly causing these hepatitis.
As for the rumors that “this time hepatitis was caused by biological weapons”, there is no evidence yet.
Facing Unexplained Hepatitis
What should Chinese parents do?
There have been no reports of this unexplained hepatitis in China. If the WHO standards were strictly followed, the same cases would certainly appear in China, because too much hepatitis could not find the cause all at once. Even if it appears in China in the future, it cannot be considered that a new virus “spreads” to China.
If it’s really adenovirus, it’s all around us, and in rare cases, it can bring hepatitis trouble. The usual health protection requirements can also be well prevented from infection.
Specific implementation, parents can do this:
- < p>Learn about the symptoms and signs of hepatitis, and if they appear, see a doctor in time. 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 your child has symptoms of a gastrointestinal infection such as vomiting and diarrhea, stay at home and wait at least 48 hours before taking your child to daycare and school.
Source: wordpress In the past two years, we can better understand that the world is not only a disease, but also should face the “new disease” with a more mature attitude. Don’t panic and misrepresent until more clear results emerge, and try to remain as objective and rational as possible.
In the future, Dr. Clove will follow up and release the news as soon as possible. We face it together.
This article reviewer
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References
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[1] https://www.cdc.gov/media/releases/2022/s0421-hepatitis-alert.html
[2] Investigation into acute hepatitis of unknown aetiology in children in England Technical briefing 25 April 2022
[3] https://en.wikipedia.org/wiki/2022_hepatitis_of_unknown_origin_in_children
[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.
Planning
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Planning: Eric | Producer: Feidi
Source of cover image: UKHSA
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