Viral Infections of the LRS

Influenza virus

Fever; muscle aches; lack of energy; headache; sore throat; nasal congestion; cough

lower respiratory epithelium destroyed and virus released to infect other cells; possible bacterial secondary infection from damaged mucocilliary escalator  (usu. bacterial bronchitis)

droplet transfer (coughing); antigenic drift and antigenic shift prevent immunity

specific antibiotics  are sometimes effective for preventing type A, but not B disease; neuramidase inhibitors are effective against both; meds are only effective if there is early treatment. Vaccines are 80-90% effective.

slight changes in a viral surface antigen that render antibodies made against a previous version ineffective

uncommon, major changes in a viral surface antigen that render antibodies made against a previous version ineffective

H1N1. Assortment of a bird, pig and human segments