Fourteen more people have tested positive for a hyper-infectious, mutant strain of the coronavirus in India, the Union health ministry said on Wednesday, taking the tally of such cases in the country to 20. Four of the new patients were from Delhi, officials in the city-state confirmed.
On Tuesday, six people — three from Karnataka and one each from Andhra Pradesh, Telangana and Uttar Pradesh — who returned from the UK were found to be carrying the new variant, which is known as VOC-202012/01.
Of the 14 new cases on Wednesday, eight were detected at the National Centre for Disease Control (NCDC) in Delhi, four at the National Institute of Mental Health and Neuro-Sciences Hospital (NIMHANS) in Bengaluru, and one each at the Institute of Genomics and Integrative Biology (IGIB) in Delhi and the National Institute of Biomedical Genomics (NIBG) in West Bengal’s Kalyani.
Apart from the four Delhi residents, a 33-year-old woman from Noida’s Sector 50, who returned from the UK on December 18, was found to be infected by the mutant strain on Wednesday.
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“As of Wednesday, of the total Covid positive UK returnees having the new strain, four are residents of Delhi. This is as per the reports conveyed to the Delhi government by NCDC,” a senior government official said, requesting anonymity. This number was later confirmed by Delhi chief secretary Vijay Dev.
Elsewhere, while Bengal confirmed its first case of the new strain, the Karnataka government said a total of seven people, including the three detected on Tuesday, tested positive in the southern state after genome sequencing of positive samples released by the Indian Sars-Cov-2 Genomics Consortium (Insacog) labs.
The place of residence of the other new patients was not known immediately.
Positive samples of those who returned from the UK recently have been sequenced in six of the 10 designated, government-run Insacog labs across the country.
According to government estimates, about 33,000 passengers arrived from the UK at various Indian airports from November 25 to December 23. Authorities have begun conducting the gold-standard RT-PCR (reverse transcription polymerase chain reaction) test on these passengers in batches, though tracing all of them is becoming a difficult task with hundreds furnishing vague addresses and switching off their phones.
Those found negative in RT-PCR tests are sent to a seven-day home quarantine, while the genome sequencing of positive samples are done at Insacog labs for the detection of the possible UK variant of Sars-Cov-2, the virus that causes Covid-19.
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Those detected with the mutant strain are being kept in single-room isolation in designated health care facilities by states. Their close contacts are also being put in quarantine even as comprehensive contact-tracing has been initiated for co-travellers, family contacts and others, according to the government.
“The situation is under careful watch and regular advice is being provided to the States for enhanced surveillance, containment, testing & dispatch of samples to INSACOG labs,” a health ministry statement said.
India also extended the suspension of flights to and from the UK until January 7 from December 31, in a bid to contain the spread of the new strain believed to have been originated in that country.
In West Bengal, the son of a senior official of the state health department tested positive for the new variant after returning from London 10 days ago, news agency PTI quoted an unnamed official as saying.
“He is undergoing treatment at the Calcutta Medical College and Hospital’s super-specialty section. He is under observation. We have advised all those who have come in contact with him to isolate themselves,” the official told PTI. He added that the patient was not having “serious health issues” at the moment.
In Karnataka, health minister K Sudhakar said of the seven people found positive for the mutant strain, three were from Bengaluru and four from Shivamogga.
The swab samples of 26 people who tested positive for Covid-19 were sent to NIMHANS to ascertain whether it was the new strain, he said. The 26 were among the 1,614 UK returnees, who underwent the tests.
First detected in London and Kent in mid-September, the variant was identified by UK authorities as a matter of concern on December 14. They later disclosed evidence that it appeared to be more transmissible, and was behind a spike in cases in the country’s capital as well as its south-east.
The variant has 23 changes in its genome, eight of which appear to influence the spike protein that the pathogen uses to latch on to host cells. Some of the other changes could make it more adept at infecting susceptible cells and possibly even evade some immune response, although detailed studies are underway.
In a preliminary assessment released late on Monday, UK scientists estimated that VOC-202012/01 did not lead to more deaths or hospitalisations but caused noticeably more secondary infections than the older variant.
The new variant has already been reported by Denmark, the Netherlands, Australia, Italy, Sweden, France, Spain, Switzerland, Germany, Canada, Japan, Lebanon and Singapore.
Clinical microbiologists said the new variant did not seem to be posing a big threat in terms of severity of the disease, even though it is capable of infecting more people in a given time.
“Increased transmissibility means more people will get infected…since there are no implications on pathogenicity, which is the ability to cause the disease, it isn’t much of a concern at the moment. For Covid-19 detection, the same RT-PCR testing will be conducted, and the government’s surveillance system is already in place to conduct large-scale genome sequencing to check for the new variant. So, nothing essentially changes on ground,” said Dr Navin Kumar, head, clinical microbiology and infection prevention, Manipal Hospital, New Delhi.