India recorded a marginal increase in COVID-19 cases over the past week as it stepped up surveillance in the wake of a fresh surge in coronavirus cases in some countries, especially China.
A little over 1,500 new cases were recorded in India over the past week, marking a slight rise over the 1,200 new cases recorded the week before.
More testing
However, the marginal rise in cases can be attributed to a dramatic shift in daily testing, which explains more cases being detected now, officials in the Union health ministry pointed out.
On January 3, a total of 134 new cases were recorded across the country, taking the total number of active infections to 2,582. But there has been a nearly three-fold rise in the tests conducted to identify new cases over the last 10 days.
On Tuesday, for example, a total of 1,51,186 COVID-19 tests were conducted across India, while this number had been less than 50,000 for most days in December.
“It is a fact that there has been a big slump in COVID-19 tests in states and that was primarily because of few people demanding the tests,” said a senior health ministry official, adding that most of the new tests now include the ones being carried out at airports.
He added that so far, there was no sign of worry for the country as the rolling average COVID-19 test positivity rate stood at a comfortable 0.13 percent, and in a number of districts across India there were no new cases being detected at all.
The government decided to carry out random COVID-19 tests on 2 percent of international passengers on every flight landing in India after December 24.
Positive COVID-19 samples are subjected to whole genome sequencing to identify the new variants.
Eye on hospitalisations
In several communiques. to the states in recent days, the Centre has asked them to keep track of the number of hospitalisations due to influenza-like illnesses and Severe Acute Respiratory Illnesses, apart from raising genomic and disease surveillance.
Thus far, no states have flagged any concerns.
“I see no reason to worry yet,” said Gautam Menon, who teaches Physics and Biology at Ashoka University and has closely followed India’s COVID-19 graph.
“There has been no increase in hospitalisation so far,” he said. “As many of us have been saying, the robust hybrid immunity that most Indians possess following three successive COVID-19 waves, and in particular the last fast-spreading Omicron wave, should help protect us.”
Omicron sub variants prevalent
India’s COVID-19 genomic surveillance consortium (INSACOG) has not released a weekly update since December 12 but a graphic representation of the week-wise lineage distribution of various SARS-CoV-2 subvariants shows that BA.2.75 and XBB are the most dominant strains as of now.
Curiously though, BA.2.75, which had earlier been sidelined by the XBB subvariant, seems to be making a comeback again. The XBB subvariant is said to be the most transmissible SARS-CoV-2 strain so far, dominating countries such as the US and UK.
A senior scientist attached with an institute under INSACOG, India’s COVID-19 genomic surveillance consortium said that this could be explained either by a geographical sampling bias, limited sequencing, additional mutations in BA.2.75 that could provide an advantage over the XBB variant, or misclassification of a new subvariant.
Only more sequencing can uncover the facts, he said.
Other INSACOG officials maintained that the subvariants thought to be behind the recent surges in China and some other nations, such as BF.7 and XBB, were detected in India much earlier.