The Life Cycle of the Influenza Virus

Influenza is a contagious viral infection of the respiratory system causing illnesses in animals and people. Because the influenza virus reproduces quickly, can mutate easily and is easy to contract, it can be difficult to prevent the spread of infection.

Initial Infection

• Influenza is spread primarily in tiny droplets expelled during coughing or sneezing. They can be easily inhaled or may come in contact with objects that a potential host may touch, thereby transmitting the disease.

Cellular Stage

• Once the virus has entered the host, it will fuse to the plasma membrane of a permissive cell within the respiratory tract, particularly in the nose, mouth and throat.

Genetic Reproduction

• The virus will enter the cytoplasm of the cell and then proceed to the nucleus. Once the virus enters the nucleus, it deposits genetic material, replicates its genome and forms new gene particles.

Extracellular Activity

• The new virus particles will then leave the cell and invade surrounding tissues to infect other cells. This process will be repeated until the virus has proliferated throughout the body.

Infectious Stage

• The virus will then be shed from the mucous membranes into the saliva and nasal discharge of the host. Sneezing or coughing will then spread the disease to other potential hosts.