Updated: February 18, 2021 8:18:49 am
Genome sequencing of random Covid-19-infected samples has found E484K mutation in one sample in Amravati and N440K mutation in another sample in Yavatmal.
Doctors say the presence of E484K could explain why entire families are testing positive in Amravati that has recorded 2,843 new Covid-19 cases in the last one week and a positivity rate of 56.7 per cent, the highest in Maharashtra.
Mutation is natural in course of viral infection as the virus jumps from one host to another, but some mutations may cause increased transmission than others. The British Medical Journal reported that E484K mutation has been found in the fast spreading South African, UK and Brazilian variants. The mutation occurs in spike protein, allowing the virus to “slip past immune response”. It has also raised concerns regarding vaccine efficacy.
“The infected person with E484K mutation and entire family were positive for Covid-19. We found high viral load in the infected person,” said a senior doctor from Amravati. More random samples will be sent soon from Amravati.
Civil surgeon Dr Shyamsunder Nikam said hospitalisations have soared in the district amidst an unusual surge although most cases are mild infections. Worried by the spike, health workers are taking to vaccination in large numbers in the district. It is not yet clear if Covishield is effective against this mutation.
In Yavatmal, the N440K mutation has been found in one of the four samples the district sent for genome sequencing. The district has 11.4 per cent positivity rate and 507 new cases in last one week. The N440K has also been found in North India, and is associated with evading antibody response. Dr Vivek Gujar, from Yavatmal molecular lab, said they plan to collect more random samples to see if this mutation is widespread.
“Like Amravati, in Yavatmal entire family of infected persons is testing positive for Covid-19. This mutation can evade antibody response, if there are reinfections this mutation may be seen in those cases. But so far we have not come across a rise in reinfections,” he said.
Dr Archana Patil, Director (Family Welfare), Directorate of Health Services, said the samples from Amravati and Yavatmal were tested in BJ Medical College (Pune), and have now been sent to National Institute of Virology for a second test for confirmation.
“Both these mutations are in spike protein of the virus. They are not severe, but they increase infectivity. They can effectively bind with ACE-2 protein and enter host cell, and try to evade the immune response. A person exposed to E484K will require more neutralising antibodies to suppress the virus than a person who does not have this mutation. N440K exhibits similar trait,” said Rajesh Pandey, scientist in CSIR-Institute of Genomics and Integrative Biology.
Maharashtra, with 38,013 active cases, has second highest cases in India after Kerala. In last one week active cases have risen in at least 21 districts of the state. Amravati, Wardha, Akola, Buldhana, and Yavatmal are all neighbouring districts that have collectively witnessed a spike in hospital admissions. In Amravati, hospitalisation and deaths have risen in last two weeks. “We are recording 3-4 deaths daily now, earlier they were 1-2,” civil surgeon Nikam said. In Buldhana, civil surgeon Dr Nitin Tadas said they are in process of sending five samples for genome sequencing. “We are seeing high infectivity. This could also be because people are less cautious about preventive measures,” he said.
Buldhana has a positivity rate of 26.5 per cent. Tadas said a series of mass gatherings has possibly led to a surge in Covid cases — from gram panchayat elections to marriages and political rallies before elections. Of 3,353 isolation beds, 783 are filled with Covid patients in the district.
There are some good and bad indicators in Covid-19 infection progression in Maharashtra. The average daily new cases has continued a downward slope from November till February if studied month wise. But a closer look at last three weeks suggests average daily new cases rose from 2,498 between January 27-February 2 to 2,646 between February 3-9 and to 3,581 between February 10-15.
At the same time, the fatality due to coronavirus has reduced from 1.63 per cent in January 27-February 2 period to 0.89 per cent in February 10-15. Even as cases are rising, fatality rate seems to remain under control for most parts of Maharashtra except five districts Raigad, Sindhudurg, Beed, Ratnagiri and Bhandara. The case fatality rate ranged between 4.6 and 7.4 per cent in these districts in last one week.
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