The first case of XE, a more transmissible Covid-19 variant, was detected in Mumbai on Wednesday, a civic health official said.
A woman who arrived from South Africa in February was found to have this Omicron sub-variant, officials of the Brihanmumbai Municipal Corporation (BMC) said, adding that she was asymptomatic and recovered from the infection.
Besides, a case of the Kappa variant of coronavirus was also detected during a sero survey, a BMC official said, adding the results came in genome sequencing of 376 samples, the 11th batch of testing in the local genome sequencing lab.
Kappa cases have been found in the city earlier too, she added.
As per the sero survey, Omicron was found in 228 out of 230 samples (99.13 per cent) collected from Mumbai. One case was of XE, and another of Kappa.
The genome sequencing of 376 samples was conducted at the municipal Kasturba Hospital’s Genome Sequencing Lab.
The condition of the patients found infected with the new strains of the virus was not serious, the official said.
Mumbai on Tuesday reported 56 Covid-19 cases, a three-fold rise from a day earlier, which took the infection count in the country’s financial capital to 10,58,185.
The death toll remained unchanged at 19,559 as no new fatality was recorded, while the recovery count rose by 36 to touch 10,38,356, leaving the metropolis with 270 active cases.
A BMC official said the XE variant appears to be 10 per cent more transmissible than the BA.2 sub-variant of Omicron. So far, BA.2 was deemed to be the most contagious of all the Covid-19 variants.
The XE variant is a mutation of the BA.1 and BA.2 Omicron strains, referred to as a “recombinant”.
As per the initial studies, the XE variant has a growth rate of 9.8 percent over that of BA.2, also known as the stealth variant because of its ability to evade detection.
The World Health Organization has said the latest mutant may be more transmissible than the previous ones.
Mangala Gomare, executive health officer of the BMC, told PTI that the woman who was found to have contacted the XE variant had arrived from South Africa and tested positive for coronavirus infection three weeks after arriving.
“She was asymptomatic and tested negative the next day,” Gomare said.
The woman, who is a costume designer, was a member of a film shooting crew. She arrived from South Africa on February 10, 2022.
“She did not have any travel history prior to that. She had been vaccinated with both doses of the COMIRNATY vaccine,” the official said, adding that she suffered from no co-morbidities.
On arrival in India she tested negative for Covid-19, but on March 2, she tested positive during routine testing. In the subsequent test, she tested negative.
She had been quarantined in a hotel rook during this period.
As to whether it was the first case of the XE variant detected in India, BMC officials said they could not confirm this.
Meanwhile, World Health Organisation’s chief scientist Dr Soumya Swaminathan has said new Covid-19 variants were unlikely to have a Delta-like impact in India in view of the country’s high vaccination rate, especially among the vulnerable population.
However, the WHO chief scientist said that surveillance is key and even if cases are are on a decline, testing should not decline and a close watch has to be kept – after the variant has been detected in 600 samples in UK
According to the WHO report, the new mutant may be 10% more transmissible than other strains according to preliminary data.
“The country can be cautiously optimistic but should be watchful and the key word here is that we must not give up on surveillance and testing,”reiterated the chief scientist. She expressed concern on how many countries had significantly lowered testing; this leaves a situation when one is not aware of what is happening regarding the state of the pandemic and emerging new variants in the community.
“So it is really important that even if the number of cases is low and clinical testing has decreased, the surveillance (SARI, ILI, wastewater surveillance) should be strengthened as it is important to understand how the virus is circulating in the community. We should also sequence a small percentage of those circulating viruses to know if there are new emerging variants and the data needs to be shared globally of course. If every country does that, we can stay ahead of the virus, otherwise we may be hit by a new variant suddenly resulting in an increased number of cases and hospitalization.
So the most important thing in the current scenario is increased surveillance and keeping the focus on vaccination of the vulnerable groups. WHO now recommends a third dose of the vaccine, starting with the vulnerable groups and then expanding to cover all adults, to make sure that everybody has protective immunity for future variants, said Dr Swaminathan. “Boosters are advisable for all adults, starting with the highest age groups. This is to further strengthen the immune response and build as much population immunity as possible,”said the scientist. She said that it is known that immunity wanes over a period of time, so the third ( booster) dose is important.
She said that there is a need for the country to ensure that there are enough drugs to treat and the clinical algorithms to treat are in place which includes medical infrastructure_beds and oxygen requirements if there is a wave. She stressed on monitoring all health indicators and keeping a close watch on non-communicable diseases and communicable diseases while at the same time being ready for any future variants
Explaining the concept of recombinant viruses, she said that there are a total of three hybrid or recombinant viruses in total that have been detected so far. These are XD, XE and XF, of which XD and XF are combinations of Delta and Omicron variants. Meanwhile, XE is a hybrid of two sub lineages of Omicron – BA.1 and BA.2. The scientist said that till date there have been five variants of concern, the last being Omicron detected in November last year. While it was known that the virus would have many lineages, the genomic sequencing has been able to track the evolution of the virus as it was expected to mutate. A recombinant virus arises when two different viruses in the same individual and in the same cell exchange a bit of genetic material. “We are still studying the XE recombinant closely and more information is coming up,”she added. So far she said that there was no need to panic as it is not showing any early trends of more severe illness or greater immune evasion to vaccination.
The country has been reporting a little over 1000 cases daily and the total covid related deaths reported in the country in the last 24 hours is below 100. With many states issuing masks only as an advisory and not mandatory the WHO chief scientist said that people should continue to take sensible precautions which means wearing of masks in crowded indoor settings or when suffering from respiratory infections.