Subtypes of HIV

Taxobox | color=violet
name = "Human immunodeficiency virus"

---

image_width = 180px
image_caption = Phylogenetic Tree of the SIV and HIV viruses.
virus_group = vi
familia = "Retroviridae"
genus = "Lentivirus"
subdivision_ranks = Species
subdivision =
* "Human immunodeficiency virus 1"
* "Human immunodeficiency virus 2"DiseaseDisorder infobox
Name = International Statistical Classification of Diseases and Related Health Problems Codes
ICD10 = B20-B24
ICD9 = ICD9|042-ICD9|044
One of the obstacles to treatment of the Human Immunodeficiency Virus is its high genetic variability.cite journal | author = Robertson DL, Hahn BH, Sharp PM | title = Recombination in AIDS viruses | journal = J. Mol. Evol. | volume = 40 | issue = 3 | pages = 249–59 | year = 1995 | month = March | pmid = 7723052 | doi = | url = ] HIV can be divided into two major subtypes, HIV 1 and HIV 2, and further subdivision can be made based on sequence data. Some of the subtypes are known to be more virulent or are resistant to different medications.

Major Subtypes

HIV 1

HIV 1 includes the most common strains of the virus, and it is further subdivided into three groups called M, N, and O.

;Group MThis is the most common type of HIV, with more than 90% of HIV cases being HIV-1 group M. It is subdivided further into clades that are also given a letter. This is further complicated due to changes in the virus during the course of infection, and many cases are given a "circulating recombinant form" or CRF which is given two letters. CRF A/C, for example, is a combination of subtypes A and C.
* Subtype A is common in West Africa.cite journal | author = Bobkov AF, Kazennova EV, Selimova LM, "et al" | title = Temporal trends in the HIV-1 epidemic in Russia: predominance of subtype A | journal = J. Med. Virol. | volume = 74 | issue = 2 | pages = 191–6 | year = 2004 | month = October | pmid = 15332265 | doi = 10.1002/jmv.20177 | url = http://dx.doi.org/10.1002/jmv.20177]
* Subtype B is the dominant form in Europe, the Americas, Japan, Thailand, and Australia. Goudsmit, Jaap. Viral Sex; The Nature of AIDS. Oxford University Press. New York, New York, 1997. Pg. 51-58. Retrieved May 25, 2008.]
* Subtype C is the dominant form in Southern and Eastern Africa, India, and Nepal.
* Subtype D is generally only seen in Eastern and central Africa.
* (Subtype E) has never been purified, and is always seen combined with subtype A as CRF A/E.
* Subtype F has been found in central Africa, South America and Eastern Europe. [http://www.avert.org/hivtypes.htm] Introduction to HIV types, groups and subtypes. March 3, 2008. Retrieved May 25, 2008.]
* Subtype G (and the CRF A/G) have been found in Africa and central Europe.
* Subtype H is limited to central Africa.
* (Subtype I) was originally used to describe a strain that is now accounted for as a combination of other subtypes.Fact|date=May 2008
* Subtype J is limited to Central America
* Subtype K is limited to the Democratic Republic of Congo and Cameroon.

These subtypes are sometimes further split into groups such as A1 or F2.Fact|date=May 2008 This is not thought to be a complete or final list, and further types will likely be found. [ [http://www.avert.org/hivtypes.htm HIV types, subtypes, groups & strains ] ]

;Group NThis group, discovered in 1998Fact|date=May 2008, has only been seen in Cameroon and is extremely rare.Fact|date=May 2008

;Group OThis strain is not usually seen outside of West-central Africa and is very rare. It caused some concern because it could not be detected by standard test kits, though more advanced HIV tests will detect it and group N. [http://www.abbottmolecular.com/PDF/E0608633_RealTimeHIV_rev.pdf]

HIV 2

Like Group N and Group O, HIV-2 has not been widely seen outside of Africa. The first case in the United States was in 1987 [ [http://www.hivworkshop.com/hiv-2.htm HIV-2 ] ] . Many test kits for HIV-1 will also detect HIV-2 [ [http://www.fda.gov/cber/products/testkits.htm CBER - Donor Screening Assays for Infectious Agents and HIV Diagnostic Assays ] ] .

References

External links

*
* [http://www.avert.org/hivtypes.htm HIV Types] at Avert.org