Human papilloma virus (HPV): Difference between revisions

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== Natural Host: ==
== Natural Host: ==
HPV is capable of infecting humans only
HPV is capable of infecting humans only.


== When was your organism discovered? ==
== When was your organism discovered? ==

Revision as of 13:22, 23 April 2009

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Human papilloma virus
Virus classification
Group: Group I (dsDNA)
Family: Papillomaviridae
Genus: Alphapapillomavirus
Vectors

human

Papillomaviruses

Papillomaviruses are nonenveloped DNA viruses. These viruses are diverse, but all can infect the skin and mucosal tissues of a many vertebrate species, including humans.[1] A group of genital mucosotropic human papilloma virus (HPV) types are etiologic agents responsible for virtually all cases of cervical cancer, as well as a substantial fraction of other ano-genital and head-and-neck cancers (reviewed in [1]). Cancer-associated genital HPV types, as well as another subset of HPV types associated with the development of benign genital warts (condyloma accuminata), are generally transmitted through sexual contact. Infection with genital HPV types is very common, with an estimated lifetime risk of infection of about 75% [2]. Although most genital HPV infections are subclinical and self-limiting, a subset of persistently infected individuals have lesions that progress to premalignancy or cancer.

Description and significance

Genome structure

The HPV genome is approximately 8,000 base pairs long and made up of 40-50% Guanine and Cytosine base pairs. Papillomaviruses have the same general genomic organization which consists of 8 open reading frames(ORF) all located on the same strand. These ORFs are designated either early (E) or late(L). The early ORFs-E1,E2,E4,E5,E6,and E7-code for nonstructural regulatory proteins. The E3 ORF does not code for a protein, and the E8 ORF has been identified only in bovine Papillomaviruses. The late ORFs-L1 and L2-code for capsid proteins. A 1-Kb non-coding region known as the upstream regulatory region (URR) ,lies between the early and late ORFs. The URR includes the origin of replication (ori), the E6/E7 gene promoter, and enhancers and silencers.

Natural Host:

HPV is capable of infecting humans only.

When was your organism discovered?

How and where it was isolated:

Interesting Features:

How does this organism cause disease?

What makes it biologically interesting?

Current Research:

Epidemiology

23% of women attending sexually transmitted disease, family planning, and primary care outpatient clinics in the United States may be positive for high-risk HPV.[2]

Prevention

I vitro studies show that carrageenan, extracted from red algae and commercially used to thicken products including sexual lubricants and infant formulas, is a potent inhibitor of HPV infection.[3]

HPV Vaccine

The HPV vaccine can reduce the incidence of high-grade cervical intraepithelial neoplasia[4] and HPV-associated anogenital disease[5].

The number needed to vaccinate to prevent the following diseases is estimated to be:[6]

A cost-benefit analysis concluded that the cost is $43,600 per quality-adjusted life-year (QALY) gained.[6]

In the United States, the Centers for Disease Control and Prevention recommends vaccination of females starting at aged 11 - 12 years.[7]

References

  1. Index of Viruses - Papillomaviruses (2006). In: ICTVdB - The Universal Virus Database, version 4. Büchen-Osmond, C (Ed), Columbia University, New York, USA. http://www.ncbi.nlm.nih.gov/ICTVdb/Ictv/fs_index.htm
  2. Datta, S. D., Koutsky, L. A., Ratelle, S., Unger, E. R., Shlay, J., McClain, T., et al. (2008). Human Papillomavirus Infection and Cervical Cytology in Women Screened for Cervical Cancer in the United States, 2003-2005. Ann Intern Med, 148(7), 493-500.
  3. Buck CB, Thompson CD, Roberts JN, Müller M, Lowy DR, Schiller JT (2006). "Carrageenan is a potent inhibitor of papillomavirus infection". PLoS Pathog. 2 (7): e69. DOI:10.1371/journal.ppat.0020069. PMID 16839203. Research Blogging.
  4. The FUTURE II Study Group (May 2007). "Quadrivalent vaccine against human papillomavirus to prevent high-grade cervical lesions". N. Engl. J. Med. 356 (19): 1915–27. DOI:10.1056/NEJMoa061741. PMID 17494925. Research Blogging. ACP Journal Club review JournalWatch review
  5. Garland SM, Hernandez-Avila M, Wheeler CM, et al for the Females United to Unilaterally Reduce Endo/Ectocervical Disease (FUTURE) I Investigators (May 2007). "Quadrivalent vaccine against human papillomavirus to prevent anogenital diseases". N. Engl. J. Med. 356 (19): 1928–43. DOI:10.1056/NEJMoa061760. PMID 17494926. Research Blogging. ACP Journal Club review JournalWatch review
  6. 6.0 6.1 Brisson M, Van de Velde N, De Wals P, Boily MC (August 2007). "Estimating the number needed to vaccinate to prevent diseases and death related to human papillomavirus infection". CMAJ 177 (5): 464–8. DOI:10.1503/cmaj.061709. PMID 17709404. PMC 1950193. Research Blogging. Cite error: Invalid <ref> tag; name "pmid17709404" defined multiple times with different content
  7. Advisory Committee on Immunization Practices (ACIP) (March 12, 2007). Quadrivalent Human Papillomavirus Vaccine Recommendations of the Advisory Committee on Immunization Practices (ACIP). Centers for Disease Control and Prevention. Retrieved on 2008-11-25.