Orthomyxovirus

Orthomyxovirus is a genus of negative-sense, single-stranded, segmented RNA viruses, transmitted by droplets made when people with flu cough, sneeze, or talk, causing respiratory tract infections. This viral family includes seven genera with influenza (Flu) being studied most. Influenza viruses can be divided into three classes, A, B, and C, largely based upon conserved antigenic differences in the internal nucleoprotein (NP). Influenza subtypes are labeled according to an H number (for the type of hemagglutinin) and an N number (for the type of neuraminidase).