Influenza viruses are the only member of the orthomyxovirus family. It is a RNA virus.
Types of influenza virus and severity of influenza:
1. Influenza A virus – causes worldwide pandemic of influenza.
2. Influenza B virus – causes major outbreaks of influenza.
3. Influenza C virus – causes minor infection of respiratory tract.
Transmission of Influenza virus:
Influenza virus is transmitted by
1. Respiratory droplets
2. Direct contact
Properties of Influenza virus:
1. Asegmented single stranded RNA virus
2. Helical nucleocapsid
3. Outer lipoprotein envelop
4. Envelop is covered by two different types of spikes (antigens), Haemagglutinin (HA) and Neuraminidase (NA).
5. The virion contains RNA dependent RNA polymerase which transcribes the viral genome into mRNA