Mysterious hepatitis in children under the lens not only in Europe, but also in the US where the CDC (Centers for Disease Control and Prevention) today issued a nationwide health alert to inform doctors and public health authorities of a group of identified children with hepatitis and adenovirus infection and to ask all doctors to pay attention to symptoms and to report any suspected cases of hepatitis of unknown origin to their local and state health departments. The cases have been detected in Alabama and the CDC is investigating with the local public health department to investigate the details of these 9 hepatitis of unknown origin that have been diagnosed in children aged 1 to 6, all previously healthy. None of them were in hospital with a SARS-CoV-2 infection. The first cases in the United States were identified in October 2021 in a children’s hospital in Alabama that admitted 5 children with significant liver damage (including some with acute liver failure) with no known cause, who also tested positive for adenovirus. Viruses of hepatitis A, hepatitis B and hepatitis C were excluded. A review of medical records identified 4 additional cases, all with liver injury and adenovirus infection. Laboratory tests report that some of these children have contracted adenovirus type 41, which most commonly causes pediatric acute gastroenteritis, CDCs explain. No known epidemiological links or common exposures were found among these children. A statewide notice in February produced no further reports. “The CDC – reads a note – are aware of an increase in cases of pediatric hepatitis without a known cause recently reported in Europe, and we are in contact with our European counterparts to understand what they are learning”. It has been confirmed in many European cases, but not in all, US experts recall. The invitation to doctors is to “consider the adenovirus test for pediatric patients with hepatitis of unknown etiology” and to report any cases of mysterious hepatitis to the CDC and to the state public health authorities.