INFLUENZA

• Influenza viruses that circulate every year are called ______ flus.

  seasonal
• All cases of influenza are caused by one of three influenza viruses:

  A, B, C
• Family of Influenza viruses

  Orthomyxoviridae
• Influenza can leave pxs vulnerable to secondary infections leading to pneumonia
• who are more susceptible to serious complications

  • pxs with emphysema & cardiopulmonary disease
  • very young, old pxs
  • pregnant women
• The two glycoproteins that make up the spikes of its envelope and contribute to virulence:

  • Hemagglutinin
  • Neuraminidase
• Glycoprotein that has agglutinating action on RBCs

  Hemagglutinin
• Glycoprotein that binds to host cell receptors of the respiratory mucosa

  Hemagglutinin
• Glycoprotein that breaks down the protective mucus coating of the respiratory tract

  Neuraminidase
• Glycoprotein that assists in viral budding and release, and participates in host cell fusion

  Neuraminidase
• Genome of influenza virus

  ssRNA
• Two mutations of glycoproteins

  1. Antigenic shift
  2. antigenic drift
• antigens gradually change their amino acid composition, resulting in decreased ability of host memory cells to recognize them

  antigenic drift
• swapping out one of the viral RNA with a gene or strand from a different influenza virus

  Antigenic shift
• The genome of the virus consists of eight separate RNA strands, except for influenza _, which has _____

  C, seven
• Prevention:

  • intramuscular inactivated vaccine with three strains
  • intramuscular inactivated vaccine with four strains
• Most commonly used treatment

  Tamiflu (oseltamivir); others: baloxavir (xofluza)