India is facing a nasty outbreak of H3N2 — worst of seasonal flu viruses

H3N2 is a strain responsible for one of the three respiratory pandemics in the past century

By DTE Staff
Published: Friday 17 March 2023

India has reported at least five deaths this season associated with H3N2 — a subtype of the influenza virus. Maharashtra reported two deaths, while Gujarat, Karnataka and Haryana reported one death each. So, why is it a concern for India?

H3N2 is a strain responsible for one of the three respiratory pandemics in the past century. Often described as the ‘problem child of seasonal flu’, the H3N2 outbreak is characterised by a more severe illness lasting longer.

The virus belongs to the flu category and has the capability to cause damage to the lungs with a fever. However, H3N2 isn’t exactly a novel virus. In 2018, it wreaked havoc in the United States. This year, it is India’s turn.

India has recorded almost 600 influenza cases, of which 451 have been classified as H3N2. Three hundred sixty-one cases of influenza infections were reported in the state of Maharashtra, while Puducherry reported 79 influenza cases, according to the Union Ministry of Health and Family Welfare.

Of the hospitalised patients, 6 per cent had clinical signs of pneumonia, 7 per cent went on to develop severe diseases requiring attention by Intensive Care Units and 10 per cent needed supplemental oxygen, according to Indian Council of Medical Research (ICMR) data.

As the spread of the virus has gained momentum, several state governments have begun initiating mitigation measures. The Puducherry government announced that all schools up to Class VIII would remain closed from March 16 to March 26 in the Union Territory.

The first detection of H3N2 dates back to 1968 in Hong Kong, when the virus jumped to humans, resulting in more than a million deaths worldwide. We are yet to fully understand why an H3N2 infection is so debilitating. This, coupled with its fast-mutating characteristic, makes developing vaccines not just essential but also tricky.

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