Flu cases on rise, experts blame mutated strain, dropping of masks

Two years after the pandemic breakout, a sudden rise in flu cases is being attributed to the phasing out of masks and a possible mutation in the influenza strain doing the rounds, revealed experts.

The Indian Council of Medical Research (ICMR) has said that the Influenza A subtype H3N2 is a major cause for the current respiratory flare-up.

“The ICMR-DHR established a pan respiratory virus surveillance across 30 virus research and diagnostic laboratories,” said ICMR, while issuing a detailed advisory.

Jacob John, a renowned virologist, said these viruses have always been around, but their spread was limited in the past two years due to people masking up.

“The virus has now found fertile ground. There is an accumulation of people who did not get it,” he said.

While people of all age groups are getting infected, doctors are seeing an increased number of cases among children and the elderly.

“We are seeing a 200 per cent increase in flu cases since November 2022. However, after the second half of February 2023, we are seeing a decline in these cases,” said Rajiva Gupta, consultant, internal medicine, CK Birla Hospital.

Doctors said that the three major reasons behind this increase are cold weather (from November through January), environmental pollution, and increased prevalence of viral infections.

“The flu cases that started trickling in in October-November have seen no let-up. It starts with a sore throat. Many develop bronchial infections. It seems like a combination of different viruses,” said Rommel Tickoo, director, internal medicine, Max Healthcare.

The current strain in circulation — H3N2 — traces its origin to the 1968 pandemic.

However, experts also said that the awareness created around viruses during the Covid outbreak has made people more aware of virology and the specific names of strains.

“These viruses have been around for a very long time. Now people know the name of their respiratory infection,” said Jacob.

Some doctors said that the strain itself has mutated and the current formulation of the vaccine is not working to tackle this flu.

A senior industry source said that the World Health Organization (WHO) is expected to come up with a new formulation of the vaccine, taking into account the strain doing the rounds.

“WHO picks up a few strains for the influenza vaccine. It was more effective two years ago. It is a common flu but it keeps mutating. We are expecting WHO to issue guidelines on the new strain,” said an industry source.

The other issue is also lack of awareness about the influenza vaccine, which has to be taken every year.

“Even the educated do not know about this vaccination. You can still get the flu but the severity would be less. The onset of winter (October-November) is a good time to get this vaccination,” said Tickoo.

Doctors also said same time last year, the Omicron variant of the novel coronavirus was more prevalent and consequently common flu cases were fewer in number.