At least one child has died of unexplained hepatitis in a growing global outbreak of the baffling cases of hepatitis in children, according to the World Health Organization.
The number of outbreaks has reached more than 170 in 12 countries and is expected to continue to grow. At least 17 children – 10 percent of cases – required a liver transplant. The children affected range in age from 1 month to 16 years, although the majority are children under 10 years of age and many under 5 years of age.
Over the weekend, the WHO reported 114 cases in the United Kingdom, 13 in Spain, 12 in Israel, six in Denmark, less than five in Ireland, four in the Netherlands, four in Italy, two in Norway, and two in France, and one. in Romania and one in Belgium. The World Health Organization also noted nine cases in the United States, all in Alabama. But two additional cases were reported in North Carolina last week, bringing the total number in the United States to at least 11. Two of the US cases resulted in transplants.
The World Health Organization has not reported the age or nationality of the child who died, but no deaths have been reported in the United States.
Although the global case count may seem low, acute hepatitis (also known as hepatitis) is uncommon in young children. Health officials in Scotland – who first sounded the alarm about unexplained cases – realized something was wrong when they saw 13 cases of acute hepatitis in children in March and April alone. Typically, Scotland records fewer than four such cases over an entire year.
Health experts around the world are working to understand the causes of acute liver injury. Affected children have consistently shown negative results for viruses that attack the liver, specifically hepatitis A, B, C, D, and E. To date, there is no clear association between cases, no association with travel, or a clear link to environmental, drug or food exposure. The vast majority of cases have not received COVID-19 vaccines, which rules out this possibility.
The main suspect remains an adenovirus, although the common family of viruses is not known to cause hepatitis in healthy children. Of the approximately 170 reported cases, at least 74 have tested positive for adenovirus, with 18 cases specifically testing positive for adenovirus type 41.
More than 50 distinct adenoviruses are known to infect humans, but they are commonly associated with respiratory, eye, and sometimes gastrointestinal, and disseminated infections. Adenoviruses have, on occasion, been linked to hepatitis, but generally only in immunocompromised children.
The World Health Organization reports that type 41 adenovirus, which has not been linked to hepatitis, commonly causes diarrhea, vomiting, fever and respiratory symptoms. Based on data from cases in the UK, the most common symptoms for children affected by the outbreak include Jaundice, vomiting and abdominal painMost of the cases did not have a fever.
The international outbreak comes as the United Kingdom and the Netherlands documented spikes in adenovirus infections in the general community, driven by people resuming normal activities that were restricted during the pandemic. As such, some experts have hypothesized that cases of hepatitis could simply be a rare outcome that was always possible from a common adenovirus—but the rare finding appears to be more common now because many immune-naive children contract adenoviruses at the same time after a pandemic. However, there is also the possibility of a new type of adenovirus emerging and explaining cases of hepatitis.
It’s also possible that it’s not caused by an adenovirus at all. Some data suggests that many children who test positive for adenovirus have only low levels of the virus in their bodies. These data raised the possibility that the presence of adenoviruses may be incidental—reflecting the high rate of transmission in the community, rather than the cause of hepatitis.
Moreover, it is also possible that adenovirus is only part of the story, and co-infections may explain the unusual cases. One possibility is that co-infection of SARS-CoV-2 and adenovirus is behind the cases. The World Health Organization noted that 20 children tested positive for SARS-CoV-2 and found that 19 others had co-infection with SARS-CoV-2 and adenovirus. But the researchers also don’t rule out the possibility that the liver injury could be a rare result of omicron infection alone or infection with an as-yet-unknown SARS-CoV-2 variant.
The World Health Organization and other experts are calling for more awareness, testing and data sharing around the world to unravel the mystery.