An onslaught of common childhood viruses may have been behind the mysterious outbreak of cases of severe liver damage in children that began popping up in late 2021, as lockdowns were relaxed and schools reopened.
Severe acute hepatitis and liver failure are extremely rare in otherwise healthy children, and the cases puzzled experts. In the United States, the Centers for Disease Control and Prevention has investigated 390 cases in 46 states since the fall of 2021. Twenty-two children needed a liver transplant, and 13 have died. Worldwide, there have been about 1,000 cases, according to the World Health Organization.
Research published Thursday in the journal Nature homes in on a possible culprit: adeno-associated virus 2, or AAV2, a virus not previously known to cause illness. In 93% of the cases investigated, the researchers detected AAV2.
But importantly, the researchers found that AAV2 didn’t appear to be acting alone. It needed “helper” viruses — other infections — to get into liver cells.