Human parainfluenza virus

This page is about microbiologic aspects of the organism(s). For clinical aspects of the disease, see Croup.

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Luke Rusowicz-Orazem, B.S.

Overview

Human parainfluenza virus is an enveloped, single stranded negative sense RNA virus with four distinct serotypes. The virus genome consists of approximately 15,000 nucleotides used to encode six structural proteins; they function to attach, enter, and fuse with the host cell, forming a complex with the RNA genome. Human parainfluenza virus is a member of the paramyxoviridae family. It is a member of one of two genuses depending on the serotype: Respirovirus or Rubulavirus. Human parainfluenza virus infects the body by infiltrating white blood cells. It is transmitted through respiratory droplets through the air, as well as physical contact with an infected individual or contaminated physical surface.

Microbiological Characteristics

Human parainfluenza virus (HPIV) is an enveloped, single stranded negative sense RNA virus.^[2]

Human parainfluenza virus is comprised of four distinct serotypes:^[3]
- HPIV-1
- HPIV-2
- HPIV-3
- HPIV-4

The human parainfluenza virus genome consists of approximately 15,000 nucleotides used to encode the following six structural proteins:.^[4]

Protein	Location	Function
hemagglutinin	Envelope	Attachment and cell entry
fusion protein	Envelope	Fusion and cell entry
matrix protein	Within the envelope	Assembly
nucleoprotein	Nucleocapsid	Forms a complex with the RNA genome
phosphoprotein	Nucleocapsid	Forms as a part of the RNA polymerase complex
large protein	Nucleocapsid	Forms as a part of the RNA polymerase complex

Human parainfluenza virus is a member of the paramyxoviridae family.
The genus for human parainfluenza virus depends on its serotype:^[4]
- Respirovirus: HPIV-1 & HPIV-3
- Rubulavirus: HPIV-2 & HPIV-4

Transmission

Human parainfluenza virus is primarily transmitted by the following:^[5]
- Airborne respiratory droplets from coughing and sneezing
- Close physical contact with an infected individual
- Physical contact with a contaminated surface

Virology

Human parainfluenza virus infiltrates histiocytes, lymphocytes, plasma cells, and neutrophils white blood cells.^[6].
- HPIV fuses with the white blood cells through the glycoproteins hemagglutinin–neuraminidase and fusion protein.^[4]
- Upon fusion, the HPIV nucleocapsid is expelled into the recipient cell cytoplasm.^[4]
- Viral transcription occurs through virus-specific RNA-dependent RNA polymerase.^[4]
- The viral mRNAs are translated into viral proteins, leading to the replication of the genome into the following:^[4]
  - Positive-sense RNA strand
  - Negative-sense RNA strand
- The negative-sense RNA strand is encapsidated by nucleoprotein and is then used for further transcription and replication.

References

↑ “phil.cdc.gov”.
↑ Vainionpää R, Hyypiä T (1994). “Biology of parainfluenza viruses”. Clin. Microbiol. Rev. 7 (2): 265–75. PMC 358320. PMID 8055470.
↑ Baron, Samuel (1996). Medical microbiology. Galveston, Tex: University of Texas Medical Branch at Galveston. ISBN 0-9631172-1-1.
↑ ^4.0 ^4.1 ^4.2 ^4.3 ^4.4 ^4.5 Henrickson, K. J. (2003). “Parainfluenza Viruses”. Clinical Microbiology Reviews. 16 (2): 242–264. doi:10.1128/CMR.16.2.242-264.2003. ISSN 0893-8512.
↑ “Human Parainfluenza Viruses | Transmission of HPIVs | CDC”.
↑ Cherry, James D. (2008). “Croup”. New England Journal of Medicine. 358 (4): 384–391. doi:10.1056/NEJMcp072022. ISSN 0028-4793.

Template:WikiDoc Sources

[urlphil.cdc.gov-1] “phil.cdc.gov”.

[ParaChar-2] Vainionpää R, Hyypiä T (1994). “Biology of parainfluenza viruses”. Clin. Microbiol. Rev. 7 (2): 265–75. PMC 358320. PMID 8055470.

[CroupType-3] Baron, Samuel (1996). Medical microbiology. Galveston, Tex: University of Texas Medical Branch at Galveston. ISBN 0-9631172-1-1.

[Henrickson2003-4] 4.0 ^4.1 ^4.2 ^4.3 ^4.4 ^4.5 Henrickson, K. J. (2003). “Parainfluenza Viruses”. Clinical Microbiology Reviews. 16 (2): 242–264. doi:10.1128/CMR.16.2.242-264.2003. ISSN 0893-8512.

[urlHuman_Parainfluenza_Viruses_|_Transmission_of_HPIVs_|_CDC-5] “Human Parainfluenza Viruses | Transmission of HPIVs | CDC”.

[Cherry2008-6] Cherry, James D. (2008). “Croup”. New England Journal of Medicine. 358 (4): 384–391. doi:10.1056/NEJMcp072022. ISSN 0028-4793.

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