Research into child hepatitis mystery

WHO looks at potential role of adenovirus and Covid 19, with cases reported in 20 nations

The WHO has said 348 probable cases of hepatitis of unknown origin have been identified, as studies into the potential role of adenovirus and Covid-19 infection gather pace.

The World Health Organization said the leading hypotheses remained those involving adenovirus.

Cases have been reported in 20 countries, with 70 additional cases from a further 13 countries which are pending classification as tests await completion.

Only six countries are reporting more than five cases, with more than 160 being reported in Britain.

“Over the last week, there’s been some important progress with the further investigations and some refinements of the working hypotheses,” Philippa Easterbrook, from the WHO’s global hepatitis programme, told a press conference.

She said Britain had been coordinating a comprehensive set of studies looking at the genetics of the children affected, their immune response, viruses and further epidemiological studies.

The WHO was first told a week ago of 10 unexplained hepatitis cases in Scotland, detected in children under the age of 10.

The US Centres for Disease Control and Prevention said last Friday it was investigating 109 such cases, including five reported deaths.

“At present, the leading hypotheses remain those which involve adenovirus – with also still an important consideration about the role of Covid as well, either as a co-infection or a past infection,” Easterbrook said.

Further testing in the past week confirmed that about 70 per cent of the cases tested positive for adenovirus, with subtype 41 – normally associated with gastroenteritis – the prevalent subtype, she added.

Testing has also shown that about 18 per cent of cases actively tested positive for Covid-19.

“The big focus over the next week is looking at serological testing for previous exposure and infections with Covid,” Easterbrook said.

The scientist said that within the week, there should be data from Britain on a case control study comparing whether the detection rate of adenovirus differed from that in other children admitted to hospital.

“That will really help hone down whether adeno is just an incidental infection that’s been detected, or there is a causal or likely causal link,” she said.

She said that microscopic studies of liver samples and biopsies had shown none of the typical features that might be expected with a liver inflammation because of adenovirus.

Adenoviruses are commonly spread by close personal contact, respiratory droplets and surfaces.

At present, the leading hypotheses remain those which involve adenovirus.

PHILIPPA EASTERBROOK, OF THE WHO’S GLOBAL HEPATITIS PROGRAMME