A mysterious hepatitis in children. What we know right now

), by mid-May they have been reported worldwide 450 cases of mysterious hepatitis in children, of which 17 have required a liver transplant and 11 have passed away. According to the World Health Organization (WHO), it is believed that the cause could be an adenovirus, but the investigation continues.

The age of those affected has varied between one month and 16 years (most are under 5). Hepatitis means inflammation of the liver and is accompanied by elevation in liver function tests. Symptoms and signs of this acutely occurring condition may include: abdominal pain, diarrhoea, vomiting, associated with elevated liver function tests and yellowing of the skin (known as jaundice). Most did not have a fever.

The first cases were identified in October of 2021 in a hospital in Alabama, in the United States. They were diagnosed with significant liver disease, some with hepatic insufficiency or failure. All tested negative for hepatitis A, B, and C, but tested positive for adenovirus. They came from different parts of the state, they were previously healthy. None had evidence of COVID-19 infection during or before their hospitalization. In total there were 9 cases.

Although hepatitis is frequently an infection of the liver caused by a virus, some drugs and some chemicals can also cause it.

The common viruses that cause viral hepatitis in children (which are viruses A, B, C, D and E) have not been detected in any of these cases. On the other hand, adenovirus has been detected in 70% of cases. In some of the cases tested, the COVID-19 virus (SARS-CoV-2) was present and in 19 cases adenovirus infection and COVID-19 simultaneously. Based on this, Philippa Easterbrook, a WHO scientist, told a news conference that the main hypothesis is that the cause of this hepatitis involves adenovirus, but that there are important considerations such as the possibility that the two years of the pandemic with social distancing and the use of masks have left the immune system of children inexperienced to fight an infection like this. Another theory is that a COVID infection at that time or previously amplifies the disease induced by the adenovirus.

According to the WHO, there are more than 50 different types of immunologically different adenoviruses that can cause infections in humans. The adenovirus type 41 that has been associated with this type of hepatitis typically presents with diarrhea, vomiting, fever, and respiratory symptoms. And, although there have been cases of hepatitis caused by the adenovirus 41 in immunocompromised children, they have not been seen in healthy children.

The relationship between the adenovirus and the COVID-vaccine-19 has been ruled out as most of the affected children had not received the vaccine. Other hypotheses are still being investigated.

The Centers for Disease Control and Prevention (CDC) say that at this time the cause of the disease is unknown. That, although the adenovirus has been detected in some children, we do not know if it is the cause of the disease. The role other factors play in this disease, such as exposure to toxins or other infections that children may have, is also being investigated.

In terms of recommendations, the WHO advises following prevention measures other common infections, such as regular handwashing and respiratory hygiene.