An unusual global outbreak of pediatric hepatitis cases in 2022 could be connected to multiple common viruses, according to multiple studies.
Three studies published March 30 in Nature found that nearly every child with an unexplained hepatitis case had high levels of adeno-associated virus 2, or AAV2. Another virus, adenovirus, may also be tied — though the pair of viruses have never before been associated with human disease. Becker's reported on one of the preprints in late July, a few days after the global count of cases surpassed 1,000.
One of the studies found AAV2 in 13 of 14 young patients with hepatitis, or liver inflammation, and co-infections of "helper viruses" — including Epstein-Barr virus, human herpesvirus 6, and/or enterovirus A71 — were found in 12 of the 14 cases. Another study of a few dozen cases revealed "an association between AAV2 infection and host genetics in disease susceptibility [...] alongside a prominent T-cell infiltrate in liver biopsies."
A third small study conducted in the U.K. yielded similar findings: The abnormal amount of hepatitis cases among children in 2022 seem to be tied to a combination of AAV2 and another aiding virus.
The CDC is investigating 391 known cases of "children with acute hepatitis of unknown etiology" across 46 states and jurisdictions, the agency said in a March 29 update.