New York (AP) — Health officials continue to be puzzled by the mysterious incident of severe liver damage in hundreds of infants around the world.
The best evidence available shows a fairly common stomach bug that is not known to cause liver problems in otherwise healthy children. The virus was found in the blood of affected children, but strangely not found in their sick liver.
“There are many things that don’t make sense,” said Eric Clemmer, a viral researcher at the Institute for Molecular Genetics in France.
When health authorities in more than a dozen countries are investigating the mystery, they ask:
— Was there any surge in stomach bugs (called adenovirus 41) that are causing more cases of previously undetected problems?
— Will pandemic-related blockades that protect children from the viruses they normally experience make them more susceptible?
— Is there a mutant version of the adenovirus that is causing this? Or other unidentified bacteria, drugs, or toxins?
— Is it some kind of Haywire immune system reaction caused by past COVID-19 infections and subsequent invasion by other viruses?
The US Centers for Disease Control and Prevention and researchers around the world are trying to sort out what’s happening.
Illness is considered rare. A CDC official said last week that he was investigating 180 possible cases across the United States. Most children were hospitalized, at least 15 needed liver transplants, and 6 died.
A total of hundreds of cases have been reported in more than 20 other countries, with the most common being the United Kingdom and the United States.
Symptoms of hepatitis (or inflammation of the liver) include fever, malaise, loss of appetite, nausea, vomiting, abdominal pain, dark urine, light-colored stools, joint pain, and jaundice.
The scope of the problem was just beginning to become apparent last month, but sick detectives say they have been tackling the mystery for months. According to experts, it was very difficult to determine the cause.
Elsewhere, the traditional causes of liver inflammation in healthy children — the virus known as hepatitis A, B, C, D, and E — did not appear in the test. In addition, the children came from different locations and seemed to have had no general exposure.
It was adenovirus 41 that appeared. More than half of the cases in the United States have been tested positive for adenovirus, and there are dozens of them. Adenovirus 41 appeared each time in a small number of specimens tested to determine what type of adenovirus was present.
The fact that adenovirus continues to emerge reinforces the claim that it plays a role, but it is unclear how Dr. Jay Butler, Deputy Director of Infectious Diseases at the CDC, told The Associated Press.
Many adenoviruses are associated with common cold symptoms such as fever, sore throat, and pink eyes. Some versions, including adenovirus 41, can cause other problems, such as inflammation of the stomach and intestines. Adenovirus was previously associated with hepatitis in children, but is primarily found in children with a weakened immune system.
Dr. Umesh Parashar, chief of the CDC group, focused on viral enteropathy, and recent genetic analysis found no evidence that it was due to a single new mutant version of the virus.
It is not clear if viral activity has surged recently, as adenovirus infections have not been systematically tracked in the United States. In fact, adenoviruses are so common that researchers do not know what to do with their presence in these cases.
“When you start testing for adenovirus, you’ll find so many children,” said Dr. Heli Bhatt, a pediatric gastroenterologist who treated two children in Minnesota with liver problems.
One was a child who came with liver failure nearly five months ago. The doctor couldn’t understand why. Unfortunately, “it happens that there is no cause,” Bert said. According to experts, about one-third of cases of acute liver failure are of unknown cause.
Bat said the second child she saw got sick last month. By that time, health officials had been paying attention to the case, and she and other doctors began to revisit the unexplained inferior illness back in October.
In fact, many of the cases added to the count in the last few weeks were not recent illnesses, but pre-reassessed illnesses. About 10% of US cases occurred in May, Butler said. He added that interest rates have seemed to be relatively flat since the fall.
According to some scientists, doctors may only be discovering a phenomenon that has been going on for years.
Another possible explanation: COVID-19.
The CDC recently estimated that as of February, 75% of children in the United States were infected with the coronavirus.
Health officials say that only 10% to 15% of children with mysterious hepatitis had COVID-19, according to a nasal swab test performed when they checked in to the hospital.
However, researchers are wondering about previous coronavirus infections. Petter Brodin, a pediatric immunoscientist at Imperial College London, said coronavirus particles lurking in the gut may play a role.
so piece Earlier this month, in the medical journal Lancet, Brodin and another scientist suggested that a combination of prolonged coronavirus and adenovirus infections could trigger an immune system response that damages the liver.
“I think it’s a combination of unfortunate situations that can explain this,” Brodin told AP.
According to Butler, researchers have seen such complex reactions before, and researchers are discussing ways to better check the hypothesis.
He said it “is not out of the realm of plausibility at all.”
Case Western Reserve University Preprint surveyAlthough not yet peer-reviewed, it suggests that children infected with COVID-19 are at significantly higher risk of liver damage.
Dr. Markus Buchfellner, Physician for Pediatric Infectious Diseases at the University of Alabama at Birmingham, was involved in identifying the first US case in the fall.
He said the illness was “strange” and worrisome. Six months later, “We don’t know exactly what we’re dealing with.”
___
The Associated Press’s Department of Health Sciences is supported by the Science Education Department of the Howard Hughes Medical Institute. AP is solely responsible for all content.