Question

The swine flu virus is formally designated as the H1N1 influenza virus. What do the H and the N stand for and what role do they play in influenza morbidity? What year did this virus cause worldwide morbidity and how many people died? Please be detailed and provide any sources cited . Thank you :)

Answer 1

H stands for hemagglutinin and N stands for neuraminidases

The H1N1 influenza virus is an orthomyxovirus and produces virions that are 80 to 120 nm in diameter, with an RNA genome size of approximately 13.5 kb. The swine influenza genome has 8 different regions which are segmented and encode 11 different proteins:

• Envelope proteins hemagglutinin (HA) and neuraminidase (NA)
• Viral RNA polymerases which include PB2, PB1, PB1-F2, PA, and PB
• Matrix proteins M1 and M2
• Nonstructural proteins NS1 and NS2 (NEP), which are crucial for efficient pathogenesis and viral replication

The surface glycoproteins HA and NA are how the H1N1-strain is differentiated from other strains of influenza A (H1N1, H1N2) depending on the type of HA or NA antigens expressed with metabolic synergy. The function of hemagglutinin is to cause red blood cells to cluster together, and it attaches the virus to the infected cell. Neuraminidase helps move the virus particles through the infected cell and assists in budding from host cells.

In 1918, a deadly influenza pandemic caused by H1N1 influenza virus, also known as the Spanish flu, infected approximately 500 million people around the world and resulted in the deaths of 50 to 100 million people (3% to 5% of the world population) worldwide, distinguishing it as one of the most deadly pandemics in human history.

In 2009, a new strain H1N1 swine flu spread fast around the world among humans, and the World Health Organization (WHO) labeled it a pandemic. However, the 2009 H1N1 virus was not zoonotic swine flu because it was not transferred from pigs to humans.

Instead, it spread through airborne droplets from human to human, and potentially, through human contact with inanimate objects contaminated with the virus and transferred to the eyes or nose.