Coronavirus in India: Scientists estimate that Covid may have entered India in November-December | India News
Leading scientists at leading research institutes in the country have estimated that the ancestor of the new Wuhan coronavirus strain was in circulation on December 11, 2019. Using a scientific technique called “time to the most recent common ancestor”, MRCA, scientists estimated the virus. The strain that now circulates in Telangana and other states originated between November 26 and December 25, the median being December 11.
It is unclear whether the virus was introduced to India by passengers from China before January 30, since Covid-19 tests were not carried out on a large scale in the country at the time.
Researchers, including from the city-based Center for Cellular and Molecular Biology (CCMB), have not only estimated the age of the most recent common ancestor of various strains of the new coronavirus, but also discovered a new strain or clade, which is different from the existing ones They have called this Clade I / A3i.
A “clade” is defined as “a group of organisms believed to comprise all of the evolutionary descendants of a common ancestor.”
The viral strain found in India’s first Covid-19 case in Kerala belonged to the ancestor Wuhan, while the one discovered in Hyderabad (Clade I / A3i) is unique in that it did not originate in China but somewhere in Southeast Asia. . The exact country of origin of this new clade is unknown, said CCMB Director Dr. Rakesh K Mishra.
Regarding the most recent common ancestor of the new strain (Clade I / A3i), it was in circulation between January 17 and February 25, with the median being February 8. Another clade, A2a, which is the predominant clade in India, had a tMRCA of January 2, with the period of its likely appearance between December 13, 2019 and January 22, 2020.
The team, which included researchers from the Institute for Genomics and Integrative Biology (CSIR-IGIB), Delhi, and the Academy of Scientific and Innovative Research, Ghaziabad, noted that the new clade is found nowhere else in the world. This is also different from the other 10 known clades previously discovered.
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The new clade was introduced to India from a single point. It was also a single outbreak. Later it saw rapid expansion, spanning multiple regions across the country. As part of the study, the team performed complete genome sequencing for 64 genomes, making a total of 361 Indian genomes. They also dated the different groups of viral genomes.
Dr. Mishra said that Clade I / A3i covers 41% of all genomes sequenced and deposited in the public domain from multiple states in India. Worldwide, 3.5% of genomes, which to date could not be assigned to any other known group, belong to this newly defined clade. Clade I / A3i is represented in 145 genomes (41.2%) and represented in 16 of the 19 states from which the genomes originated.
Tamil Nadu, Telangana, Maharashtra and Delhi have the highest proportions of this new clade, followed by Bihar, Karnataka, UP, West Bengal, Gujarat and Madhya Pradesh. Haryana, Jammu and Kashmir, Madhya Pradesh, Odisha and Rajasthan each have a genome under Clade I / A3i.
Watch Covid-19 may have entered India in November-December last year