H3N2, Swine Flu, and COVID-19 Make Their Round Abouts in India

Are you also a victim of the flu that has been going around the country? Don’t worry, you are not the only victim. This flu has practically taken over the country, and if you thought that this is it, then you might want to reconsider this question because a couple of viruses that are known to be past culprits of pandemics have teamed up to brew up that viral cocktail. According to the government, H3N2 accounts for roughly 79% of all influenza viruses discovered in samples from people suffering from severe acute respiratory infections (SARI) or influenza-like sickness (ILS). The second most prevalent viral subtype is Influenza B Victoria (14%), a subtype of Influenza B, while the third most common influenza virus is Influenza A H1N1 (7%), also known as swine flu.

Here are some historical flashbacks that are associated with the viruses that are again taking the world by storm.

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H3N2- a Pandemic from the Past

The influenza A H3N2 virus also caused the 1968 pandemic that killed over a million people. According to Encyclopedia Britannica, "The 1968 flu pandemic, also called the Hong Kong Flu Pandemic of 1968 or the Hong Kong Flu of 1968, was a global outbreak of influenza that originated in China in July 1968 and lasted until 1969–70. The outbreak was the third influenza pandemic to occur in the 20th century; it followed the 1957 flu pandemic and the influenza pandemic of 1918–19. "

Something that we can ponder is why we are having an outbreak again. The answer to that is, we’re seeing more cases because as the virus mutates a little bit, our immunity to it diminishes a little bit, and susceptible people tend to get infected more readily.

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The Swine Flu Outbreak and Pandemic

In 2013, India experienced a large outbreak of swine flu.

By the end of February, it had taken 310 lives. This is concerning given that 405 people died from the flu in 2012. While the government has gone into overdrive to limit the number of cases, data from AIIMS research in Delhi reveals that there is no need to panic (1^✔ ✔Trusted Source
Lessons learnt from the Indian H1N1 (swine flu) epidemic: Predictors of outcome based on epidemiological and clinical profile

Go to source).

According to specialists, the behavior of the swine flu virus strain has become similar to seasonal influenza.

Before the 2009 H1N1 pandemic, the influenza A (H1N1) virus had never been recognized as a cause of human infections. The virus's genetic analysis revealed that it originated from animal influenza viruses and is unrelated to the human seasonal H1N1 viruses that have been in wide circulation since 1977.

The swine flu pandemic, considered one of the shortest pandemics, was declared over by the WHO in August 2010. Since then, the unique virus has undergone numerous modifications, and the swine flu pandemic was declared over in August 2010.

Seasonal influenza viruses are classified into four types: A, B, C, and D. According to the WHO, influenza A and B viruses circulate and produce seasonal epidemics of disease.

An (H1N1) pdm09 is the name of the new virus that caused the 2009 pandemic. The H1N1 (2009) virus is still circulating as a seasonal virus and is included in seasonal influenza vaccinations (2^✔ ✔Trusted Source
Types of Influenza Viruses

Go to source).

Influenza A viruses are the only influenza viruses known to generate flu pandemics (global outbreaks of flu disease), according to the Centers for Disease Control and Prevention in the United States.

During late December 2022 and early January 2023, an outbreak of a respiratory ailment with symptoms of cold, sore throat, fever, and weariness was detected across India.

The Indian Council of Medical Research (ICMR) confirmed on March 4 that this sickness was caused by influenza subtype H3N2. According to ICMR data, H3N2 infections increased in the first nine weeks of 2023. Since December 15, this virus has been the most prevalent.

"At least 92 percent of the hospitalized SARI (severe acute respiratory infections) patients examined by the agency who were detected with the virus had a fever, and up to 86 percent had a cough," according to the report. Also, 27% developed dyspnea, and 16% developed wheezing symptoms. In addition, 16% showed indications of pneumonia, and 6% experienced seizures, according to the ICMR in a media statement.

The report also stated that the virus tended to cause more hospitalizations than other influenza subtypes.

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Past to Future, Influenza is Still Here with us

For almost 6000 years, influenza has afflicted humans, creating pandemics at regular intervals. There are rising cases that are associated with this virus and its varying strains. Along with this, the world is still suffering and recovering from COVID-19, and the trajectory has fallen significantly in recent months. The progressive rise in COVID-19 test positivity rates in several states is a worrying issue that must be addressed immediately.

Reference:

1. Lessons learnt from the Indian H1N1 (swine flu) epidemic: Predictors of outcome based on epidemiological and clinical profile - (https://pubmed.ncbi.nlm.nih.gov/30613550/)
2. Types of Influenza Viruses - (https://www.cdc.gov/flu/about/viruses/types.htm)

Source-Medindia