MEDizzy - In March 2009, the H1N1 strain of the infuenza A virus

Feed Library Learning Discuss Leaderboard Journal

Infection causing diseases 2

In March 2009, the H1N1 strain of the infuenza A virus emerged in Mexico and quickly spread worldwide over the next several months. Ultimately, over 18,000 people died due to the pandemic. This virus had genetic components of swine infuenza viruses, an avian virus, and a human infuenza virus. The genetic process by which this pandemic strain of infuenza A emerged is an example of which of the following?

ExplanationThe emergence of the H1N1 strain of influenza A in 2009, with genetic components of swine influenza viruses, an avian virus, and a human influenza virus, is an example of both antigenic shift and genetic reassortment. Antigenic shift refers to a major change in the influenza virus antigens, particularly the hemagglutinin (H) and neuraminidase (N) proteins, resulting in the emergence of a new subtype. This can occur when different influenza virus strains infect the same host, allowing for the exchange of genetic material and the creation of a new strain with a unique combination of antigens. Genetic reassortment, also known as genetic recombination, occurs when two different influenza viruses infect the same host cell and exchange genetic segments. This process can lead to the creation of a novel strain with a combination of genes from the two parental viruses. In the case of the H1N1 pandemic strain, it resulted from the reassortment of genetic material from swine, avian, and human influenza viruses. Therefore, the emergence of the H1N1 pandemic strain in 2009 involved both antigenic shift and genetic reassortment.