The number of reported cases of influenza-A subtype H3N2 has surged recently in India, and there have been some fatalities. The government has responded by closely monitoring the situation and issuing advisories. While there is no need to panic, it is important to be aware of the risks and take necessary precautions to protect oneself from the virus.
The Centre conducted a review meeting last week as cases of influenza continue to rise. States are on high alert and preparing hospitals to treat patients with the viral infection. In March, the Union Health Ministry confirmed two deaths caused by the H3N2 subtype of influenza virus – one in Haryana and one in Karnataka. However, data from the Integrated Disease Surveillance Programme revealed that at least nine people died due to the flu in January alone.
According to the Union Health Ministry’s data, 3,038 cases of laboratory-confirmed influenza were reported in India until March 9, which is not significantly high in comparison to last year’s total of 13,202 cases. However, it is important to note that the actual number of cases may be higher due to the fact that not everyone gets tested for the flu and not all the results are reported to the government.
Officials and experts have given reasons for the current rise in influenza cases in India. Firstly, it is the flu season and India typically sees two peaks every year – between January and March and post-monsoon between August and October. The changing seasons create an ideal environment for the virus to spread. Alongside flu, other respiratory infections such as adenovirus and Covid-19 are also being reported.
Secondly, fewer flu infections during the pandemic have left large sections of the population with weakened immunity. Dr. Sujeet Singh, former director and advisor at National Centre for Disease Control, said that every year there is a sub-clinical spread of influenza and people acquire some immunity to it. However, during the pandemic, people stayed away from crowded areas, avoided gatherings, and masked up, which prevented the spread. Consequently, there is an increase in cases this year. In 2020 and 2021, fewer flu cases were reported, with 2,752 and 778 cases respectively.
H3N2 Cases Spike as Flu and COVID-19 Hit Country Simultaneously
India is facing a surge in respiratory illnesses with Covid-19 cases rising to their highest in four months. At least five states have higher positivity rates than the rest of the country, with Gujarat, Maharashtra, Tamil Nadu, Kerala, and Karnataka having a positivity rate of 1.1-2.8%. On top of this, there has been a spike in influenza cases, with around 9 daily cases since the first week of January. Doctors are noticing a significant surge in patients with similar complaints, including H3N2. Mumbai doctors say there is a 100-150% rise in patient visits with flu-like symptoms. Amid rising cases of H3N2 and other respiratory illnesses, the Puducherry government has declared holidays for schools for 11 days from March 16-26. The government machinery is active, with the Centre warning six states of a rise in Covid-19 positivity rates. India is witnessing a surge in H3N2 influenza virus cases, and symptoms persist for days after the primary viral infection heals.
Understanding the H3N2 Virus?
Influenza viruses are categorized into four types: A, B, C, and D. Only types A and B are known to cause seasonal outbreaks or epidemics in humans, while type C typically causes mild illness, and type D does not affect humans. Influenza A viruses are further classified into more than 130 subtypes based on two proteins, hemagglutinin (H) and neuraminidase (N), found in nature. H3N2 is one of the two subtypes of influenza A that circulate regularly among humans, the other being H1N1. Influenza B is also a circulating strain. The 1968 Hong Kong flu, which resulted in millions of deaths, was caused by H3N2, whereas the 2009 Swine Flu pandemic originated from a new strain of the H1N1 virus.
Which population groups are vulnerable to the virus?
According to experts, certain population groups are at a higher risk of contracting seasonal influenza. Unvaccinated children have a 20% chance of getting infected, while the risk for unvaccinated adults is 10%. There are five groups that are particularly vulnerable, including children aged 6-59 months, pregnant women, the elderly, adults with comorbidities, and healthcare workers. WHO recommends that these groups get vaccinated, but the coverage is low in India, with only 1.5% of the elderly population vaccinated. The government has advised health workers dealing with current H1N1 cases to get vaccinated.
How can one prevent and treat the flu?
Experts recommend taking specific actions to prevent the spread of influenza. Individuals who become infected are given drugs to treat their specific symptoms, such as fever and cough. Antiviral medications, such as Oseltamivir, are recommended only for the high-risk population or in specific cases. To prevent infection, experts advise wearing masks in crowded places, covering your mouth and nose with a handkerchief while sneezing or coughing, staying home if you feel sick, and frequently washing your hands. Some experts predict that the number of cases will likely decrease by the end of March or mid-April as the temperature rises.