Rise in H1N1 Cases

About H1N1 Influenza:

• Nature of virus: H1N1 is a subtype of the Influenza A virus, commonly known as swine flu. It can infect both humans and pigs, primarily causing respiratory illnesses.
• Transmission: The virus spreads through respiratory droplets when an infected person coughs, sneezes, or talks. It can also be contracted by touching contaminated surfaces.
• Contagious period: The virus is contagious from the day before symptoms appear until about four days after they start. Children and immunocompromised individuals may remain contagious for a longer period.
• First case in India: The first confirmed case of H1N1 in India was reported in May 2009. Since then, the virus has caused several outbreaks, with significant case numbers recorded in 2021, 2022, and 2023.

Current situation:

• Affected states: Punjab (41 deaths), Kerala (34 deaths), and Gujarat (28 deaths) are the states with the highest mortality rates. The highest number of cases have been reported in Delhi, Gujarat, and Kerala.
• Comparison: The last significant surge occurred in 2022, with 13,202 cases and 410 deaths.

Recent developments:

• New Strain: The Pune-based National Institute of Virology observed that the virus has undergone point mutations, leading to the emergence of a new strain called the Michigan strain, which has replaced the previously prevalent California strain. This shift is linked to the increased cases and mortality rates observed in 2024.
• Mutation impact: The virulence of the virus has remained largely unchanged, but the mutation has rendered previous vaccinations less effective against the new Michigan strain.

Q1. What is Influenza A virus?

Influenza A virus is a pathogen that causes the flu in birds and some mammals, including humans. It is an RNA virus whose subtypes have been isolated from wild birds.

Source: Most number of deaths by H1N1 in Punjab, Kerala, and Gujarat - The Hindu