Orthomyxovirus

Definition

Orthomyxovirus is a family of RNA viruses that includes the influenza viruses, which cause respiratory infections in humans. These viruses are characterized by their segmented genome and ability to undergo genetic reassortment.

5 Must Know Facts For Your Next Test

1. Orthomyxoviruses have a segmented RNA genome, which allows for genetic reassortment leading to antigenic shift.
2. Influenza A, B, and C are the main types of orthomyxoviruses affecting humans, with Influenza A being the most severe.
3. Hemagglutinin (HA) and neuraminidase (NA) are surface proteins critical for viral entry and release from host cells.
4. Antigenic drift refers to small mutations in the HA and NA genes that can lead to seasonal flu variations.
5. The annual flu vaccine targets strains predicted to circulate based on surveillance data.

Related terms

Hemagglutinin:

A glycoprotein found on the surface of influenza viruses that facilitates viral entry into host cells.

Neuraminidase:

An enzyme on the surface of influenza viruses that helps release new virus particles from infected cells.

Antigenic Drift:

Gradual mutations in viral genes leading to changes in surface proteins, causing new virus strains.