New reports of unusual hepatitis cases among children in the U.S. have brought the global total to 348 probable cases from 20 countries, the World Health Organization said May 10.
Five updates:
1. The 348 probable cases, up from 228 probable cases reported May 4, reflect new and retrospective cases, according to Philippa Easterbrook, MD, a senior scientist in the global hepatitis program at the World Health Organization. An additional 70 cases are pending confirmation.
2. While the WHO has identified cases in five global regions, six countries are reporting five or more cases.
3. Dr. Easterbrook said U.K. researchers have made "some important progress" in studying the cause of the unusual cases. The leading hypothesis is that an adenovirus is responsible for the illnesses, though researchers are still examining the potential role of a COVID-19 coinfection or past infection.
4. About 70 percent of children who've been tested were positive for an adenovirus. Over the last week, researchers have also analyzed children's liver tissue samples, which do not show "any of the typical features you might expect with a liver inflammation due to adenovirus," Dr. Easterbrook said.
5. On May 6, the CDC updated its testing guidance for treating children with severe hepatitis. The agency said clinicians should conduct a standard diagnostic work-up for children with the condition and also consider testing for adenovirus.