Thread by @kakape

Quickly catching the special session on hepatitis of unknown aetiology at #ECCMID22 before heading back to Germany.

Aikaterini Mougkou of @ECDC_EU gives an update on cases in EU
Currently reported cases are higher than expected in Ireland and Netherlands, maybe Denmark.

@ECDC_EU Some of the limitations of the data:
- "it is unclear if there's underestimation of cases as not all countries have robust data systems and not all cases have been defined with the same criteria”
- "We do not know if there are children with subclinical presentation"

@ECDC_EU "We don't have answers yet, but we do have hypotheses and perhaps the first few pieces of the puzzle as we start to test those hypotheses”, says @meera_chand.
"I hope by sharing this today, that we will be able to accelerate investigations in other countries”

@ECDC_EU @meera_chand The 81 cases resident in England are not known to be epidemiologically linked, dispersed all over the country, says @meera_chand. Vast majority of cases are 1-6 years old. 7 cases have needed transplantation, no deaths.

@ECDC_EU @meera_chand Paediatric liver units are seeing increased activity, “but we don't see a huge change in wider NHS presentations of jaundice and hepatitis through normal clinical coded data”, says @meera_chand
Some low level fluctuations "which we're investigating in more detail at the moment”.

@ECDC_EU @meera_chand Nothing stuck out in broad questionnaires on food, drugs, medical history, epidemiological links etc.
Paracetamol clearly needed to be considered, she says, but no indication for that playing a role.

Pathogen testing:
lot of variability in timing of tests which may affect chance of capturing the pathogen
„But what you can see here is that we have a high adenovirus positivity it's present in 40 of 53 confirmed cases which have been tested so around 75%“

Presenting some interesting data on the spike in adenovirus infections particularly in GI samples in young children in recent weeks. (Of course other pathogens have seen similar patterns to some extent)

So main hypothesis:
Adenovirus infection plus some co-factor. That co-factor could be
- susceptibility (lack of prior exposure during pandemic)
- prior infection with #SARSCoV2 (maybe just Omicron) or other infection
- coinfection with #SARSCoV2 or other infection
- toxin, drug

Other hypotheses:
- novel adenovirus variant
- drug, toxin, environmental exposure
- novel pathogen alone or as co-infection
- new variant of #SARSCoV2

Q: Does the increase in adenovirus infections alone explain the increase in severe cases?
“We've had a lot of discussion about this”, says @meera_chand, worth thinking about, but "adenovirus hepatitis in immunocompetent child is a very, very uncommon phenomenon"