| Description : |
The influenza A viruses are negative-sense, single-stranded, segmented RNA viruses of the genus Alphainfluenzavirus, family Orthomyxoviridae. There are several subtypes, named according to the type of Haemagglutinin (H1-18) and Neuraminidase (N1-11). Humans are generally infected by influenza viruses of the subtypes H1, H2 or H3, and N1 or N2. In April 2009, a new virus, referred to as A/(H1N1) pdm09, appeared in Mexico and California (US), and was responsible for the first pandemics of the 21st century (claiming several hundred lives). It spreads rapidly from person to person, and is not related to any circulating inter-pandemic viruses. It is a quadruple reassortant virus, consisting of two swine-origin viruses, one avian-origin virus and one human-origin virus. It has a high fatality rate and shows higher incidence among younger people. WHO convenes technical consultations in February and September each year to recommend viruses for inclusion in influenza vaccines for the northern and southern hemisphere influenza seasons, respectively. |
| Reference : |
1. Azekawa S, Namkoong H, Mitamura K, Kawaoka Y, Saito F. Co-infection with SARS-CoV-2 and influenza A virus. IDCases. 2020;20:e00775. Published 2020 Apr 21.
2. Baldo V, Bertoncello C, Cocchio S, et al. The new pandemic influenza A/(H1N1)pdm09 virus: is it really "new"?. J Prev Med Hyg. 2016;57(1):E19-E22.
3. Centers for Disease Control and Prevention. (2017). Influenza Type A Viruses. |
