A.2 lineage of monkeypox samples found in US, UK, India and Thailand should be explored further: NIV study
The ten monkeypox confirmed cases were comprised of three male and two female from New Delhi with no international travel history. While five males were from Kerala with a travel history from the United Arab Emirates (UAE) to India
As the B.1 variant is found to be the predominant lineage of the 2022 monkeypox outbreak globally, the introduction event of A.2 lineage specifically in the US, UK, India and Thailand is the question of further exploration concluded a recent paper ‘Genome characterisation of monkeypox cases detected in India: Identification of three sub-clusters among A.2 lineage,’ published by Indian Council of Medical Research (ICMR) scientists.
The paper was published in bioRxiv - the preprint server for biology on Friday.
Dr Pragya Yadav, lead author of the paper and scientist with the Indian Council of Medical Research - National Institute of Virology (ICMR-NIV), Pune, said that these changes during microevolution might play an important role in the increased transmission and/or disease severity in case of monkeypox.
“ICMR-NIV performed genome characterisation of monkeypox cases detected in India. And it was found that the samples belonging to lineage A.2 have further diverged into three sub-clusters. The recent update in monkeypox lineage designated all five sequences from Kerala as A.2.1. The samples of all ten cases were characterised which tested positive for monkeypox from Kerala and Delhi between July to August 2022,” said Dr Yadav.
From July to August 2022, swab samples of 96 suspected monkeypox cases from 18 states and 3 Union Territories (UT) were sent to the ICMR-NIV for diagnosis of monkeypox. Of them, ten cases tested positive. Out of these five cases, each from Kerala and Delhi was found to be positive for monkeypox.
“The ten monkeypox confirmed cases were comprised of three male and two female from New Delhi with no international travel history. While five males were from Kerala with a travel history from the United Arab Emirates (UAE) to India. All the cases were immunocompetent with no comorbidities. All the cases have recovered without complications except a case from Kerala who succumbed to the infection following acute onset Encephalitis,” said Dr Yadav.
She further added that India quickly identified the first two cases of monkeypox among UAE returnees in July 2022.
“The genomic analysis revealed the infection of these cases with lineage A.2 of subclade IIb. This lineage has 80 nucleotide changes compared to the B.1 lineage which has been the predominant lineage of 2022 suggesting an independent virus strain emergence,” said Dr Yadav.
“Further studies are needed to determine the impact of this divergence in A.2 lineage. The genome evolution mechanisms and importance of gene functions also need to be studied further to understand the evolution of the monkeypox genome,” said Dr Yadav.