H3N2 flu surge drives infectivity in 25% Indians tested: Govt data

A 25% positivity rate is considered high for seasonal influenza in India and indicates a widespread outbreak. The high positivity rate can be directly linked to the rapid spread and virulence of the latest H3N2 strain, which is currently the dominant circulating subtype of the virus.

Of the 100,000 samples collected between January till September, some 25,000 cases were confirmed as flu, per data from hospitals uploaded to the central government's Integrated Health Information Platform. This data is closely tracked by the country's apex biomedical researcher, the Indian Council of Medical Research, and the National Centre for Disease Control (NCDC), the government's disease and public health institute' accurate.

Mint has reviewed the data. Queries sent to the health ministry spokesperson remained unanswered.

Seasonality

The peak of this flu season hit in August and September following monsoon rains raising public health concerns across the country.

The data reveals that the H3N2 virus is the most common strain, accounting for some 10,000, or 40%, of the confirmed cases. The H1N1 virus, also a common swine flu strain, was detected in about 4,000 samples.

The high percentage of H3N2 cases is a cause for worry given the vulnerability of young children, men with pre-existing conditions, and the elderly, who make up a significant portion of the affected, a government official said, declining to be identified.

A specialist doctor called for urgent public health communication. "This recent spike is a significant public health issue," said Dr Sanchayan Roy, Senior Consultant in Internal Medicine at Apollo Spectra Hospital, New Delhi. “We need to place a greater emphasis on flu vaccination, hygiene, and early detection to contain the spread. Public awareness campaigns, particularly in schools and workplaces, are crucial for minimizing transmission."

Fast mutation

A scientist familiar with the research pointed to the risk of influenza leading to more serious illnesses. “The influenza virus has a tendency to change suddenly, it's very unstable," the scientist said. "The key is to diagnose and detect these respiratory viruses early so they don’t develop into more serious conditions like pneumonia." The scientist requested anonymity.

NCDC last year recorded 20,414 H1N1 cases and 347 deaths in India, numbers that highlight the seriousness of these infections. It is early to track data on H3N2 year to date because the virus is still spreading rapidly.

The rise in flu cases in the last nine months needs to be studied further for better public health strategies, an expert said. “We see these surges every now and then. We need to go by the pattern it is showing, when and where the peaks are," said Dr Jayaprakash Muliyil, virologist and former principal of Christian Medical College, Vellore.

Meanwhile, at the individual level, Dr Soumya Swaminathan, the former Chief Scientist for the World Health Organization, had a simple piece of advice: "When infections are on the rise, it's always advisable to wear a mask in crowded places and wash your hands frequently."