Shanghai, Beijing, Hangzhou and other places have entered a critical period of anti-epidemic, and there is nervous news from overseas:
Many countries reported unexplained acute hepatitis in children, mainly concentrated in Europe, and the latest news on the 25th showed that a very similar case of unexplained hepatitis also appeared in Japan.
Image source: CCTV
I have not yet got rid of the new crown pneumonia, and I have come to hepatitis of unknown cause, and it is inevitable to worry about fear. Could this be a new threat to human health? What the hell is going on with these hepatitis?
Global epidemic of hepatitis of unknown cause
Beginning in October 2021, a children's hospital in Alabama, USA, has found 9 children with acute hepatitis who have tested negative for routine hepatitis virus. Subsequently, the specific causes of hepatitis were analyzed until a more serious situation occurred in Europe.
Beginning on 31 March 2022, unexplained childhood acute hepatitis is gradually being reported across the UK. On 5 April, the UK informed WHO of this for the first time.
After April 8, similar reports began in Ireland, Spain and other places in Europe.
On 15 April, WHO made the first public reference to hepatitis in the UK.
On 23 April, WHO announced that at least 169 cases of childhood acute hepatitis of unknown etiology have been identified in 12 countries, including 114 cases reported in the United Kingdom, 13 cases in Spain, 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 bulletin also sets out the diagnostic criteria for this unexplained hepatitis recommended by WHO.
For the first time, 1 case of highly similar unexplained hepatitis was reported in Japan.
Will unexplained hepatitis replicate the COVID-19 pandemic?
Among the many current cases, hepatitis did not spread rapidly from the UK to Japan, and it has not been confirmed that it is caused by the transmission of the same etiology.
The total number of cases is less than 200, which is not significant against the huge global population base. Why did this hepatitis stir up an uproar? Not only in more than a dozen countries that have been affected, but also in China, which has not reported cases, it is also of great concern.
The descriptions of "unexplained reasons" and "multinational appearances" suddenly bring our memories back to more than 2 years ago, at the end of 2019, when we saw similar words.
Unknown origin is actually not uncommon in the diagnosis of diseases, and humans do not have the ability to identify the cause of the disease at once. Many unexplained diseases may never know the outcome, and may find the answer after a while.
In the early days of COVID-19, we also called the unrecognized situation uninjusted pneumonia.
Today, this kind of unexplained hepatitis is still quite different from the original pneumonia of unknown cause.
First of all, the vast majority of the causes of pneumonia are some kind of pathogen infection, when we also found a new virus in patients through genetic sequencing, the murderer was about to come out, but in a short period of time, it was impossible to ensure that it was caused by this new virus, nor could it be determined whether there was human-to-human transmission.
Hepatitis is more extensive, and it is not only pathogen infection that can cause hepatitis. There are many other factors, such as autoimmune hepatitis, such as hepatitis caused by poisoning by poisons such as heavy metals. The portrait of the murderer is very vague.
Secondly, after the report of pneumonia of unknown cause, it is concentrated in the same area of the same city, or even near a certain area, which is in line with the law of the gradual spread of pathogens.
However, the "spread" of hepatitis did not follow biological laws. "Jumping" is scattered all over the world. Multinational reports are related to changes in perception. 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 criteria for unexplained hepatitis, the Japanese control standard, "We may have it too".
Now these more than a hundred cases of unexplained hepatitis, it is very likely that it is not the same thing, it is a variety of hepatitis cases that originally exist in various places, temporarily roughly classified together, not what many people say "hepatitis quickly spread from the United Kingdom to Japan".
From past data, 5% to 30% of acute hepatitis is "unexplained". This proportion may be higher in cases of severe hepatitis in children, with about half of children with acute liver failure unexplained.
There is little evidence that unexplained hepatitis will also reproduce the process of the infectious disease pandemic that plagued the world from unexplained pneumonia to soon, and those unpleasant memories will most likely not be repeated.
Medical experts see hepatitis of unknown origin
Human adenovirus type F41 is currently the most likely unexplained cause of hepatitis found, but it remains unconfirmed.
This unexplained hepatitis is unlikely to be the beginning of a pandemic, but it has also attracted the attention of the WHO. The main reason is that the concentration appears in a short period of time, or it is a bit unusual, unlike the sporadic case of acute unexplained hepatitis in children.
The country with the most cases and the most studies is the United Kingdom. The intensive 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 and ruled out the most common causes of hepatitis, namely various hepatitis viruses.
Many viral infections can cause mild or severe liver damage. There is a class of viruses that specifically attack the liver, collectively known as "hepatitis viruses". Includes hepatitis A, B, C, D, and E viruses. The most common cause of hepatitis is this type of viral infection.
After excluding the above hepatitis viruses, continue to pay attention to toxicological investigations. In some cases, blood full metal analysis has been completed, and testing for key liver toxicants, including acetaminophen and aflatoxin, has also been carried out. There are currently no positive reports.
Then there is the investigation of autoimmune hepatitis. Autoimmune hepatitis is currently indirectly excluded by testing negative for blood autoantibodies.
Finally, the suspect was put back on the virus. In addition to the specialized hepatitis virus, other viruses can sometimes be the mastermind of liver damage.
Image source: References
According to the latest report on the 25th, various virus tests have been completed. The Adenovirus (adenovirus) on the far left is the virus that patients are most commonly detected. (Green: test positive, Blue: test negative, Yellow: results to be returned, Orange: not yet tested)
Adenoviruses are a very common virus around us. Data show that the most common pathogen of respiratory infections in children with fever is adenovirus. Adenoviruses can be transmitted through the fecal-oral route, 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 sequenced the whole genome of 11 patients with adenovirus infection, with patients with more severe diseases preferred. It was found that all 11 cases were human adenovirus type F41 (HAdV-F41) in adenovirus. Previous cases in the United States had the same result.
After this series of tests and exclusions, the UK Health Security Agency said that the human adenovirus type F41 was the most likely cause of unexplained hepatitis.
Because of the hepatitis caused by this adenovirus infection, in addition to the jaundice manifestations of liver damage, there will also be diarrhea, nausea and other digestive tract symptoms.
Of course, there are also some voices of doubt. Some scholars believe that the number of adenoviruses detected so far is not high, and it may just happen to be carried, but it is not the main cause of the disease. More detailed analysis is needed in the future to determine inferences for the present.
High incidence of abnormal adenovirus hepatitis
Adenovirus infections are frequent, mainly mild respiratory infections, and a small number of adenovirus hepatitis are not surprising, and there will be cases in previous years. But why is this episode appearing?
The current speculation is mainly the doctrine of "immunization debt".
After humans are born, there are two ways to obtain immunity. One is passive immunity gained through natural infection/recovery, and the other is active immunization obtained through vaccination.
There is no vaccine for adenovirus, so more immunity is built during exposure to the virus. Because of the COVID-19 pandemic, children stayed at home more, had little contact with other children, and had problems with immunity debt. That is, long-term low exposure to a particular pathogen leads to insufficient protective immunity, making a larger proportion of the population susceptible to the disease.
Image source: References
This is an adenovirus infection reported in the UK since 2017. You can see the obvious trough of infection in 2020 and 2021, which is the safest time for children to contact each other. But as exposure increased, the infection rebounded significantly. In particular, adenovirus infection in CHILDREN aged 1 to 4 in the UK has seen a peak not seen in previous years. 1 to 4 years old also happens to be the age group for children with this unexplained hepatitis.
More adenovirus infections may create a small number of hepatitis caused by adenovirus.
No unexplained hepatitis of adenovirus was detected
What's the matter?
It may seem that adenovirus is the most plausible explanation at the moment, but what happened to unexplained hepatitis that did not detect adenovirus?
In the UK, there are a small number of unexplained hepatitis with adenovirus undetected, and more cases have been reported in other countries, with adenovirus negative.
This is mainly related to WHO's current definition of unexplained hepatitis. In the report released by the WHO on the 23rd, the provisional definition criteria are as follows:
Children under 16 years of age with acute hepatitis, non-hepatitis A, B, C, hepatitis D, hepatitis E, and serum transaminases > 500 IU/L as of 1 October 2021.
This is obviously a more rough criterion, and other viral infections that have been excluded from the UK study, hepatitis that have not detected poisons for the time being, and less typical autoimmune hepatitis may meet this rough criterion and temporarily enter the category of unexplained hepatitis.
For example, the unexplained hepatitis reported in Israel, in further analysis, it was found that it is likely to be autoimmune hepatitis.
If the future standard remains this rough requirement, more cases will be reported. The essential reasons behind them should be mixed.
These claims of unexplained hepatitis are not credible
Myth 1: Hepatitis is related to adenovirus vaccine
The adenovirus vaccine does not bring about adenovirus infection.
It is speculated that the main cause of hepatitis is adenovirus, so some people think of the new crown vaccine. China, as well as the UK, do have people who have been vaccinated against the adenovirus route.
However, the adenovirus route vaccine, which only relies on part of the structure of the adenovirus that has a genetic defect and cannot continue to replicate (and is not yet a human adenovirus), theoretically will not cause liver damage due to adenovirus infection due to adenovirus vaccine injection, or similar adenovirus infection.
Adenovirus route vaccines have been used for many years and have never been reported to cause adenovirus infection before. This time, all the patients in the UK, because of the age relationship, not one person has been vaccinated against the new crown adenovirus route.
Statement 2: Hepatitis of unknown cause is caused by the new crown virus infection
Covid-19 infections do have rare reports of liver damage caused by hepatitis. However, among the patients with unexplained hepatitis reported this time, it is not the impact of the new crown virus.
Again, in the case of the most well-informed PATIENTS in the UK, of the 61 patients who have clearly reported that they have been admitted to the hospital and tested for the new crown virus, only 10 cases are positive for the new crown virus, less than 1/6. This ratio happens to be the proportion of COVID-19 positives within the UK child community, so it cannot be considered that the new crown virus is directly responsible for these hepatitis.
As for the rumor that "this hepatitis was caused by biological weapons", there is no evidence at present.
Face unexplained hepatitis
What should Chinese parents do?
There have been no reports of this unexplained hepatitis in China. If the WHO standards are strictly followed, the same cases will definitely occur in China, because too much hepatitis can not find the cause at once. Even if the future appears in China, it cannot be considered that a new virus has "spread" to China.
If it is indeed an adenovirus, then it is all around us, and in a few cases it can cause hepatitis trouble. The health protection requirements that are usually followed can also prevent infection very well.
Specifically, parents can do this:
1. Understand the symptoms and signs of hepatitis, and if they appear, see a doctor in time. For example, the whites of the eyes or skin, yellowing of the urine (jaundice), fever, unusual tiredness, loss of appetite, nausea, vomiting, diarrhea.
2. Teach your child to pay attention to hand hygiene and wash your hands with hand sanitizer and water. Alcohol disinfection has limited effect on adenovirus.
3. Teach your child to pay attention to other routine hygiene habits, such as trying not to touch the eyes, nose, and mouth with unclean hands.
4. Try to avoid people with symptoms of the disease.
5. If your child has symptoms of gastrointestinal infections such as vomiting and diarrhea, stay home and send them to nurseries and schools for at least 48 hours after the symptoms disappear.
Image source: wordpress
After experiencing the new crown epidemic in the past two years, we can better understand that the world is not only a new crown disease, but also a more mature attitude to face the "new disease". Until more definitive results emerge, don't panic and misinform, and keep an objective and rational attitude as much as possible.
In the future, the changes of unexplained hepatitis will be updated, and Dr. Lilac will also follow up with the release news for the first time. We face it together.
This article is reviewed by experts
bibliography
[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.
[JIANG Tao,OUYANG Wenwen,TAN Yanfang,TANG Lian,ZHANG Hui,KANG Zhen,ZHENG Xi,LI Shuangjie. Etiology and prognosis analysis of 120 cases of acute liver failure in children[J].Chinese Clinical Journal of Practical Pediatrics,2020(06):422-423-424-425.
Planning and production
Starter: Dr. Lilac
Curator: Eric | Executive Producer: Feidi
Cover image from UKHSA