The Gujarat government on Monday said that the low recovery rate and higher mortality in the coronavirus cases in the state could be attributed to the dominance of ‘L’ strain of the COVID19 virus present in the state.
In a video briefing this morning, Gujarat state health secretary Dr Jayanti Ravi said that there are two strains of the coronavirus-‘S’ strain and ‘L’ strain. She added that the ‘S’ strain which is witnessed in cases in Kerala and other states has a mild impact while the ‘L’ strain as witnessed in the patients in Gujarat is much more fatal, claiming that the heightened virulence of the strain found in Gujarat is the reason for the lower discharge rates and a higher number of COVID-19 related deaths in the state.
She also said that the Gujarat government arm-Gujarat Biotechnology Research Centre(GBRC) has come out with the entire genome sequence of the virus, adding that samples of ‘L’ strain are to be collected from the patients including those who die of the deadly contagion.
Strains of coronavirus
As per a study published in the National Science Review, the more virulent L type of coronavirus was found more in the initial stages of Wuhan outbreak, but its rate of occurrence diminished due to human intervention. Titled as- ‘On the origin and continuing evolution of SARS-CoV-2’, the study asserted that based on the population genetic analyses of 103 SARS-CoV-2 genomes, it was revealed that these viruses evolved into two major types (designated L and S), that are well defined by two different SNPs that show nearly complete linkage across the viral strains sequenced to date.
“While the L type was found in the early stages of the outbreak in Wuhan, the commonness of the L type decreased after early January 2020. One of the reasons for this could be the human intervention that posed selective pressure on the L type, which might be more aggressive and spread more rapidly. On the other hand, the S type, which is the ancestral version and less aggressive, may have increased in relative frequency due to relatively weaker selective pressure,” according to the study.
As per a report published in the Indian Express, an infectious disease specialist at the Sterling hospital, Atul Patel claimed that the mortality rate in Kerala is extraordinarily low because most of the patients in Kerala came from Dubai which has the milder S strain. He also added that the ‘L’ strain, which is viciously aggressive, was more prevalent in European countries like Italy and Spain, which have seen a large number of coronavirus casualties. “In the US, the New York data is entirely different from the rest of its states. Patients from New York were all travellers from Europe,” he said.
Out of over 3000 confirmed cases of the disease, Gujarat has seen 133 deaths.