Health and Tech: Surge in seasonal flu detected to H3N2 virus

Cases of influenza due to H3N2 in India started rising in December, 2022 and continues across many States even in March

Hyderabad: In a recent surveillance to track Influenza like Illnesses (ILI) and Severe Acute Respiratory Infections (SARI) carried out across the country by laboratories attached to Indian Council of Medical Research (ICMR), a surge in seasonal flu cases was detected due to influenza A (H3N2) virus.

The emergency of Influenza A (H3N2) as a dominant circulating viral strain wasn’t a surprise because before the Covid pandemic, the influenza A virus and its subtypes were the main viruses that routinely caused epidemics. In fact, the swine flu A (H1N1) triggered a major epidemic in 2009 and went on to infect a large cross-section of people in Telangana till SARS-CoV-2 became the dominant variant.

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Based on ILI and SARI surveillance, cases of influenza due to H3N2 in India started rising in December, 2022 and continues across many States even in March.

Influenza A Virus

Throughout the history of mankind, influenza (commonly known as flu) is well known for causing pandemics including the Spanish flu of 1918 that claimed millions of lives. In 2009, a new strain A (H1N1) of influenza (swine flu) triggered a major pandemic in United States, Europe, India and other countries.

So far, researchers across the world have identified four different influenza virus types that include A, B, C and D out of which Influenza A virus is the most noted one because it causes avian flu and swine flu.

The influenza A viruses cause respiratory disease in humans and animals and result in regular seasonal ailments, apart from triggering pandemics. According to the World Health Organization (WHO), worldwide the annual epidemics due to influenza are estimated to result in about 3 to 5 million cases of severe illness and about 2,90,000 to 6,50,000 respiratory deaths.

Due to the nature of the influenza viruses, genetic changes occur continuously in their genome that complicates the vaccine development. Antiviral drugs are also administrated for the treatment and prevention of influenza viruses.

It is self-limiting

Given the vast amount of experience gained while handling influenza cases, public health officials in Hyderabad have said that there is no reason for people to panic. The seasonal flu itself is self-limiting among healthy individuals and the symptoms will persist only for 7 to 10 days.