Human Parainfluenza Viruses - Classification

Classification

The first hPIV was discovered in the late 1950’s. The taxonomic division is broadly based on antigenic and genetic characteristics, forming four major serotypes. These include:

• Human parainfluenza virus type 1 (hPIV-1) (most common cause of croup)
• Human parainfluenza virus type 2 (hPIV-2) (causes croup and other upper and lower respiratory tract illnesses)
• Human parainfluenza virus type 3 (hPIV-3) (associated with bronchiolitis and pneumonia)
• Human parainfluenza virus type 4 (hPIV-4) (includes subtypes 4a and 4b)

hPIV is closely related to a recently formed virus grouping, the 'megamyxoviruses' (Hendra and Nipah) and closely linked to the metapneumovirus. hPIV is divided within two genera: Respirovirus (hPIV-1 & hPIV-3) and the Rubulavirus (hPIV-2 & hPIV-4).