First possible US death reported in international outbreak of child hepatitis

The first child death in the US is being investigated by health officials, as well as the second worldwide, linked to a growing international outbreak of unexplained liver inflammation.

In a health alert Wednesday, Wisconsin health officials said they are investigating four cases of unexplained hepatitis in children that match the profile of the outbreak cases. One of the cases resulted in a transplant and the other was a death.

At least five US states have reported cases of mysterious and severe hepatitis in children. Alabama health officials initially reported nine cases, which happened between October and February. There were five cases last November in the same large children's hospital in the state.

Unexplained inflammation and injury in children is uncommon. Health experts say they usually see a few sporadic cases in a year. Alabama health officials identified the four others after becoming suspicious of the five November cases. Two of the nine cases required transplants, but they were not fatal.

There were two cases of school-aged children in North Carolina that did not require a transplant. One of the three suspected cases of children under the age of 10 resulted in a transplant. On Thursday, officials in California said they were investigating seven cases.

International outbreak

The US cases join more than 160 reported worldwide. The United Kingdom, which first sounded the alarm over the outbreak, has reported the most, with at least 114 cases this year. Other countries that have reported cases include: Spain (13 cases), Israel (12), Denmark (6), Ireland (<5),>

The ages of the children stricken in the outbreak range from 1 month to 16 years. According to the World Health Organization, 17 children in its most recent tally required transplants, which is about 10 percent. The Wisconsin cases are not included in their tally.

There are a number of symptoms, including abdominal pain, vomiting, and jaundice. The majority of the cases have not presented with a high temperature.

Health experts are trying to understand the cause of the illnesses. There is no link between common foods, medicines, toxins, environmental exposures, or international travel. Some of the cases have tested positive, but not all. The vast majority of people have not beenvaccinated against COVID-19.

Suspects and speculation

The prime suspect is adenoviruses type 41. That is also puzzling. There are more than 50 types of adenoviruses. They cause colds and sometimes infections. Most of the time, adenoviruses are linked to hepatitis in children. The children who have been affected by the hepatitis outbreak are often reported to have been previously healthy.

At least 74 of the children in the outbreak have tested positive for an adenoviruses, with subtyping frequently detecting adenoviruses type 41. In England and Scotland, more than 70 percent and 50 percent of cases tested positive for adenoviruses. According to the European Centre for Disease Prevention and Control, all 11 cases were found to be adenoviruses type 41. In Alabama, there were five cases from November that all tested positive for type 41.

It has not been linked to the disease. There are usually infections with vomiting, respiratory symptoms, and a high temperature.

In an alert Thursday, the ECDC noted that their current leading hypothesis is that a cofactor affecting young children having an adenoviruses infection, which would be mild in normal circumstances, causes a more severe infection or immune-mediated liver damage.

Other hypotheses are still being considered. A new adenoviruses variant, an adenoviruses-SARS-CoV-2 coinfection, and a rare outcome of an omicron infection are included. A common adenoviruses could be the reason for the rare outcome of hepatitis cases. The WHO said that cases are more prevalent now because children are getting adenoviruses at the same time.

Health officials ask clinicians to be on the lookout for cases and have provided testing guidance for suspect cases. International data sharing is called for by WHO. The ECDC concluded that this is a public health event of concern because of the unknown aetiology, the affected population, and the potential severe outcome.