Human parainfluenza viruses

Human parainfluenza viruses (HPIVs) are the viruses that cause human parainfluenza. HPIVs are a paraphyletic group of four distinct single-stranded RNA viruses belonging to the Paramyxoviridae family. These viruses are closely associated with both human and veterinary disease. Virions are approximately 150–250 nm in size and contain negative sense RNA with a genome encompassing about 15,000 nucleotides.

The viruses can be detected via cell culture, immunofluorescent microscopy, and PCR. HPIVs lack antiviral drug options and vaccine, remain a major contributor toward the annual burden of hospitalisations among children younger than age 5—being second only to respiratory syncytial virus (RSV) in this regard—and are the predominant cause of laryngotracheobronchitis (also known as croup).