Human parainfluenza viruses

Human parainfluenza viruses
Virus classification
Group:	Group V ((-)ssRNA)
Order:	Mononegavirales
Family:	Paramyxoviridae

Human parainfluenza viruses
Classification and external resources
ICD-10	B34.8, J12.2, J20.4
ICD-9	480.2
DiseasesDB	30631
MedlinePlus	001370
MeSH	D018184

Transmission electron micrograph of parainfluenza virus. Two intact particles and free filamentous nucleocapsid

Human parainfluenza viruses (HPIVs) are a group of four distinct serotypes of enveloped single-stranded RNA viruses belonging to the paramyxovirus family.^[1]

Parainfluenza viruses can be detected via cell culture, immunofluorescent microscopy, and PCR.

Clinical significance

They are the second most common cause of lower respiratory tract infection in younger children. Together, the parainfluenza viruses cause ~75% of the cases of Croup.

Repeated infection throughout the life of the host is not uncommon. Symptoms of later breakouts include upper respiratory tract illness as in a cold and sore throat. The incubation period of all four serotypes is 1 to 7 days. In immunosuppressed people, such as transplant patients, parainfluenza virus infections can cause severe pneumonia, which can be fatal.^[2]

Prevention

Though no vaccines currently exist, research is underway.^[3]

Parainfluenza viruses last only a few hours in the environment and are inactivated by soap and water.^[4]

Types

There are four serotypes.^[5] These include:

• HPIV-1 (most common cause of croup; also other upper and lower respiratory tract illnesses typical)
• HPIV-2 (causes croup and other upper and lower respiratory tract illnesses)
• HPIV-3 (associated with bronchiolitis and pneumonia)
• HPIV-4 (includes subtypes 4a and 4b)

Notes

1. ^ Vainionpää R, Hyypiä T (April 1994). "Biology of parainfluenza viruses". Clin. Microbiol. Rev. 7 (2): 265–75. PMC 358320. PMID 8055470. http://cmr.asm.org/cgi/pmidlookup?view=long&pmid=8055470. 
2. ^ Sable CA, Hayden FG (December 1995). "Orthomyxoviral and paramyxoviral infections in transplant patients". Infect. Dis. Clin. North Am. 9 (4): 987–1003. PMID 8747776. 
3. ^ Sato M, Wright PF (October 2008). "Current status of vaccines for parainfluenza virus infections". Pediatr. Infect. Dis. J. 27 (10 Suppl): S123–5. doi:10.1097/INF.0b013e318168b76f. PMID 18820572. http://meta.wkhealth.com/pt/pt-core/template-journal/lwwgateway/media/landingpage.htm?an=00006454-200810001-00018. 
4. ^ "CDC - Human Parainfluenza Viruses: Common cold and croup". http://www.cdc.gov/ncidod/dvrd/revb/respiratory/hpivfeat.htm. Retrieved 2009-03-15. 
5. ^ "Parainfluenza Viruses". http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=mmed.section.3128. Retrieved 2009-03-15.