The first two cases of Monkeypox virus detected in India earlier this month had different genetic sequencing of samples, which indicates that the strain spreading in the country is different from the ones linked to the ‘super-spreader’ events identified in Europe. This proves that a distinct strain of the Monkeypox virus has been silently spreading in the world's population since at least year 2021. The genome sequence of the isolated strain showed a 99.85 percent match with the West Africa strain of Monkeypox virus.
Currently, most of the over 20,000 monkeypox virus cases in more than 75 countries are believed to have reported through super-spreader events in Europe and a majority of these, that happened in 2022, are of the strain named ‘B.1’. However, a few cases from around the globe appear to belong to a different strain, namely ‘A.2’. Experts from the Indian Council of Medical Research-National Institute of Virology (ICMR-NIV), Pune, uploaded the genetic sequences of the monkeypox virus on a public database for researchers, GISAID, a global science initiative.
Vinod Scaria, leading genomic scientist with IGIB, took to Twitter and posted a thread, which said that the A.2 genomes are from the US and Thailand, and have not originated from any incidences related to Europe. He went on to mention that the two genomes reported in Kerala are from the small distinct A.2 cluster. He said, "We might be looking at a distinct cluster of human-human transmission and possibly unrecognised for years (sic)."
Scaria also noted that some cases are of the A.2 strain, which includes the ones from India, they all seem to have travel history links to the Middle East or West Africa. He further added in the thread, "The earliest sample in the cluster from USA is indeed from 2021 suggesting the virus has been in circulation for quite some time, and earlier than the European events." Last month, genetic data from the US had also indicated that there are at least two different monkeypox outbreaks happening simultaneously.