A Rare Outbreak of Hepatitis in Children Has Doctors Baffled

Over 1,000 children in the U.S., U.K., and other countries have contracted an unusual form of hepatitis since the spring, and there’s still no clear cause. According to the World Health Organization, the outbreak has resulted in dozens of liver transplants and at least 22 deaths. Scientists are scrambling to find answers as to what’s causing this new spate in cases—yet many basic aspects of the outbreak remain a mystery.

For one, scientists aren’t even sure if it’s an outbreak or not, since it’s unclear what normal rates of unexplained hepatitis in children are. In the U.S., where a cluster of hepatitis cases in Alabama was reported in May, a virus called adenovirus type 41 was detected in five patients’ blood samples. Jacqueline Tate, an epidemiologist at the Centers for Disease Control and Prevention’s Division of Viral Diseases, told The Daily Beast that clinicians do not routinely test for adenovirus in hepatitis cases, prompting the CDC to issue a recommendation that they start doing so for the sake of the ongoing investigation.

“The hypothesis that we are looking into is: ‘Is it associated with adenovirus?’” Tate said. Adenovirus 41 is known to cause hepatitis in immunocompromised children, but the children who have contracted severe liver infections were otherwise healthy. Tate added that the mechanism by which adenovirus infection might be related to these cases and other co-infections is unknown.