Influenza is caused by influenza viruses types A, B, and C. Type A is the most virulent in humans and causes pandemics through antigenic drift or shift. It commonly infects the respiratory tract causing symptoms like cough, fever and sore throat. Treatment involves antivirals, supportive care and antibiotics for secondary infections. Parainfluenza and respiratory syncytial virus are other common respiratory viruses that often infect children and cause croup or pneumonia.

1. Influenza, Parainfluenza & RSV Dr Kamran Afzal Asst Prof Microbiology

2. Influenza

10. Where do “new” HA and NA come from? Nicholson KG et al. Lancet. 2003;362:1733-45

13. Influenza

31. Parainfluenza

35. Respiratory Syncytial Virus

39. Prevention

41. Orthomyxoviruses Types A, B, C : NP , M1 protein Sub-types: HA or NA protein M1 protein helical nucleocapsid (RNA plus NP protein) HA - hemagglutinin polymerase complex lipid bilayer membrane NA - neuraminidase