New Delhi, May 15 (IANS): Worldwide about 450 children have been infected with the mysterious acute hepatitis condition, while 12 have lost their lives, according to the European Centre for Disease Prevention and Control (ECDPC).

The liver disease that was first reported in the UK in April, has seen 12 deaths reported from Indonesia (5), Palestine (1), the US (5) and Ireland (1). The highest number of cases have been reported from the UK (176) and the US (110), another 100 are jointly from European countries including Austria, Belgium, Cyprus, Denmark, France, Ireland, Italy, Netherlands, Norway, Poland, Portugal, Spain, and Sweden.

According to the World Health Organisation (WHO), 21 countries have now detected 'severe hepatitis of unknown origin' among children mostly under the age of 10 since early April. At least 26 youngsters have required liver transplants.

While so far there is no reason identified, adenovirus -- a common family of infections responsible for illnesses from colds to eye infections -- is suspected to be causing the condition. Amongst 176 UK cases, about 126 have been tested for adenovirus of which 91 had adenovirus detected (72 per cent). Amongst cases the adenovirus has primarily been detected in blood.

But the ECDPC in a statement said: "Other hypotheses and possible co-factors are under investigation. Most cases continue to be reported as sporadic un-linked cases."

However, adenovirus has only been detected in blood or plasma samples for many of the cases, and also in low viral loads.

Thus, even the WHO noted that since "adenovirus has not yet been identified in the liver tissue samples analysed and therefore, could be a coincidental rather than a causal factor".

The UK Health Security Agency (UKHSA) also detected SARS-CoV-2, the virus causing Covid-19, in 24 cases out of 132 with available results (18 per cent).

The agency noted that "SARS-CoV-2 serological testing is in process".

In a bizarre twist last week, the health chiefs in the UK also investigated whether 'dog exposures' are to blame, the Guardian reported.

The UKHSA said last week that a 'high' number of the British children with hepatitis were from families which own dogs.

However, the officials did not explain how dogs could potentially be to blame, but they are known carriers of adenovirus strains, the report said.