A few weeks ago, on April 15, the World Health Organization (WHO) issued an alert about an outbreak of cases of acute childhood hepatitis of unknown cause. The first ten cases were identified by the United Kingdom in children under ten years old, without pre-existing conditions, and were reported to the entity in early April. So far, about 200 cases have been reported in other European countries, the United States and Asia, and since then, scientists around the world have been trying to find out what is causing the disease. But what exactly is childhood hepatitis?
“Hepatitis is the name given to an inflammatory process of the liver, which usually occurs as a result of infectious conditions”, explains pediatric infectious disease specialist Alfredo Elias Gilio, coordinator of the Immunization Clinic at Hospital Israelita Albert Einstein and professor at the USP School of Medicine. . The main causes of hepatitis are viruses (A, B, C, D, E), but the disease can also be triggered by excessive use of some medications, an autoimmune disease, alcohol and drug use.
In children, hepatitis usually manifests as abdominal pain, diarrhea, vomiting, nausea, and loss of appetite. In most cases it evolves into jaundice – which is that yellowish color in the skin and whites of the eyes. Other signs of hepatitis are dark urine and whitish stools. “There are cases in which the child will not have jaundice, but, in general, it is this yellowish color in the eyes that draws the attention of parents. It is at this time that they usually seek a doctor”, warns Gilio.
How is the diagnosis?
In general, given these symptoms and after a detailed anamnesis of the child’s condition and clinical history, the doctor orders some tests of liver enzymes in the blood to confirm the diagnosis – when there is inflammation in the liver, the amount of these enzymes in the bloodstream increases. .
Once the diagnosis is confirmed, it is necessary to know the cause/origin of hepatitis. “In children, most of the time, the most common cause is hepatitis A. In general, it does not require hospitalization, it is not usually serious, and most cases progress well. There is no specific remedy for the treatment, we take care of symptoms and the organism itself recovers”, explains Gilio.
Hepatitis A transmission occurs by fecal-oral contagion, by ingestion of contaminated food and/or water and in places with poor sanitation conditions. A less common form of transmission is through sexual intercourse. Professor Giglio points out that as there is a vaccine for hepatitis A and B in the National Vaccination Calendar, the number of cases of viral hepatitis in children is decreasing in Brazil.
Cases of unknown origin
What caught authorities’ attention in the UK cases was the unknown origin of the outbreak in the children – all under 16, most under 10, all healthy. Types A, B, C, D and E viruses, which are the most common causes of the disease, were ruled out. After carrying out a series of tests, the scientists realized that most cases had the presence of adenovirus 41F.
According to Gilio, there are more than 50 adenovirus subtypes and, in general, they cause mild cases of respiratory and non-gastrointestinal problems. But it is still not possible to say that this subtype is the cause of acute cases of childhood hepatitis, since it was not found in all samples.
“The cause of this outbreak is still an assumption, an observation. We need more robust data to answer the questions: do these cases have anything to do with the child’s previous infection with Covid-19? Does Covid-19 change the answer immune system in children? Is it really the adenovirus that is causing hepatitis? Could it be that the genome of this adenovirus has changed and it has become more aggressive? There are many questions that we still don’t know how to answer”, stated Gilio. “One thing we already know is that the cases have nothing to do with the coronavirus vaccine, mainly because they happened in children in an age group that was not vaccinated. [abaixo de 5 anos]. This needs to be reinforced,” the professor continued.
There are still no answers about the origin of the outbreak, but according to Gilio, there is no reason for parents to panic. The orientation is to look for a doctor if the child presents any of the symptoms related to the disease. “There is no need to despair, we are still not aware of any case in Brazil”, he concluded.