THE number of United States children who have died from a mysterious form of hepatitis has risen to six and the condition has been tied to 180 cases, announced health authorities yesterday, as they continued to hunt for the cause.

The leading hypothesis remains that adenovirus 41 has a major role, but the Centres for Disease Control and Prevention (CDC) is looking at other factors too, such as whether prior infection with Covid-19 makes children more susceptible.

“I want to caution that it does take time to assess the evidence,” CDC’s Jay Butler told reporters, stressing that the cases are not a sudden outbreak, but instead go back several months.

The CDC is still trying to confirm “whether this is a true increase in the number of cases of hepatitis in children or an existing pattern that has now been revealed through the improvements in detecting cases”.

Several hundred such cases have been reported globally, with the highest number, 197, in Britain.

There is no evidence of any link to coronavirus vaccines, with the majority of cases among children under 5-years-old and too young to have received the shots.

CDC scientist Umesh Parashar said the agency estimates that there are 1,500 to 2,000 pediatric hospitalisations for hepatitis in children under 10 for causes other than hepatitis viruses A, B and C in the US every year.

Even if adenovirus 41 is driving a small increase of around 100 hospitalisations over a year, it will be hard to pick up in the data, he added.

Butler said genetic sequencing showed that multiple strains of adenovirus 41 have been detected in children with the hepatitis – a finding that suggests it is not one single highly mutated “super” adenovirus at play.

Other theories include that the country may be experiencing a cluster of cases because Covid-19 lockdowns stopped the spread for a few years, or a lack of exposure to pathogens during lockdowns may have made children’s immune systems more susceptible.

The United Kingdom Health Security Agency initially put forward another hypothesis that the presence of dogs in a household may play a role – “but in talking with them further, they have not seen that hypothesis pan out”, said Butler.

Adenoviruses are commonly spread by close personal contact, respiratory droplets and surfaces. There are more than 50 types of adenoviruses, which most commonly cause colds, but also several other diseases.

The CDC recommends preventive action such as hand washing, avoiding sick people, avoiding touching one’s eyes, nose or mouth, and covering coughs and sneezes. – AFP, May 21, 2022.