Recently, there has been a trend of concentrated episodes of previously disseminated acute hepatitis in children of unknown origin. Acute hepatitis in children reported in several countries was initially identified in countries such as Europe and the United States, and later appeared in several countries in Asia and other countries. This has caused a high degree of alarm among relevant researchers in China.

“Acute hepatitis of unknown origin is very damaging to the liver function of children.” Ning Qin, director of the Department of Infection at the National Medical Center for Major Public Health Events and Tongji Hospital of the Tongji Medical College of Huazhong University of Science and Technology (hereinafter referred to as Tongji Hospital), told Science and Technology Daily on May 13 that, in addition to the great harm, another important reason for the incident to cause concern is that it occurred centrally in a short period of time. In the past, this kind of unexplained hepatitis in children was disseminated and the number of cases was small, but this time the number of reported cases in a short period of time is high, which has the potential to cause infection.

　　But what is puzzling is that if it is an infectious disease, there is no spatial or temporal intersection between children in different countries or regions, so theoretically there can be no mutual transmission, and how is it concentrated over a period of time?

　　Doubtful”, many causes of disease “can not be matched”

　　As of May 3, about 228 cases of acute hepatitis in children of unknown origin had been reported in 20 countries and territories worldwide, including at least 20 cases of liver transplantation, accounting for about 8.8 percent of cases, and four deaths.

　　“The affected children have common characteristics, such as the presence of jaundice and elevated transaminase indicators.” Professor Luo Xiaoping, director of the Department of Pediatrics at Tongji Hospital, said that when such cases are encountered, hospitals follow the routine process of screening for viral hepatitis, non-hepatophilic viral infections, autoimmune hepatitis, metabolic liver disease and drug-related infections, and determine the cause based on the results.

　　The World Health Organization investigated cases of acute hepatitis of unknown origin and ruled out hepatitis A, B, C, D, E, and other hepatitis virus infections, so what exactly is the cause?

　　Some scholars speculated that it might be T-cell-based autoimmune hepatitis triggered by vaccination with the New Crown mRNA vaccine. However, further investigation revealed that most of the affected children were not vaccinated with the New Crown mRNA vaccine, and this possibility was ruled out.

　　Molecular biology tests revealed the presence of a human adenovirus (HAdV) type 41 in some of the patients’ serum samples, and it is now the biggest “suspect”. But the problem is that, according to past experience, human adenovirus is not that destructive.

　　“People have studied human adenovirus more deeply, from the molecular structure to pathogenicity, to different tissue orientation, different toxicity are better understood.” Ning Qin said that human adenovirus mostly invades the respiratory tract, a few trigger gastroenteritis, conjunctivitis, resulting in liver failure is even more rare cases.

　　Infection with a new variant of the new coronavirus is one of the possible causes

　　Currently, the industry believes that in addition to human adenovirus infection, there are other possibilities, such as a new hepatophilic virus that has not yet been identified, a new variant of human adenovirus, drugs, toxins or environmental exposure, and other factors …… There is also analysis that infection with a new variant strain of the new coronavirus is also considered one of the possibilities.

　　“Although some cases have tested positive for new coronavirus and/or human adenovirus, genetic identification of the virus is needed to determine the association between the two.” Ningqin said further in-depth research is needed to determine whether it is a novel virus.

　　In addition, it may be that the virus is more pathogenic due to increased susceptibility in young children during the new coronary pneumonia epidemic and should be tested on blood, serum, urine, stool and respiratory samples and even liver biopsy samples from affected children.

　　“In fact, it is inconclusive whether the unexplained childhood hepatitis occurring in various countries is caused by the same etiology.” Ning Qin said there is no evidence that the cases occurring in different places are caused by the same cause, so international exchanges and cooperation should be strengthened, such as achieving the sharing of gene sequencing results in the international academic community, in order to solve the mystery earlier.