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| __NOTOC__
| | #REDIRECT [[Human Immunodeficiency Virus]] |
| {{AIDS}}
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| {{CMG}}
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| ==Overview==
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| '''Acquired immune deficiency syndrome ''' ('''AIDS''') is a [[syndrome|collection of symptoms and infections]] resulting from the specific damage to the [[immune system]] caused by the [[HIV|human immunodeficiency virus]] (HIV) in humans,<ref>{{cite web
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| |url=http://www.niaid.nih.gov/Publications/hivaids/hivaids.htm
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| |title=The Relationship Between the Human Immunodeficiency Virus and the Acquired Immunodeficiency Syndrome |publisher= NIAID
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| |accessdate=2008-03-10}}</ref> and similar viruses in other species ([[Simian immunodeficiency virus|SIV]], [[Feline immunodeficiency virus|FIV]], etc.)
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| ==Causes==
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| {{details|HIV}}
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| AIDS is the most severe acceleration of [[infection]] with HIV. HIV is a [[retrovirus]] that primarily infects vital organs of the human [[immune system]] such as [[T helper cell|CD4<SUP>+</SUP> T cells]] (a subset of [[T cell]]s), [[macrophage]]s and [[dendritic cell]]s. It directly and indirectly destroys CD4<SUP>+</SUP> T cells.<ref name=Alimonti>{{
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| cite journal
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| | author=Alimonti JB, Ball TB, Fowke KR
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| | title=Mechanisms of CD4+ T lymphocyte cell death in human immunodeficiency virus infection and AIDS.
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| | journal=J. Gen. Virol. | year=2003 | pages=1649–1661 | volume=84 | issue=7 | pmid=12810858 | doi=10.1099/vir.0.19110-0
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| }}</ref> CD4<SUP>+</SUP> T cells are required for the proper functioning of the immune system. When HIV kills CD4<SUP>+</SUP> T cells so that there are fewer than 200 CD4<SUP>+</SUP> T cells per [[microliter]] (µL) of [[blood]], [[cellular immunity]] is lost. In some countries, such as the United States, this leads to a diagnosis of AIDS. In other jurisdictions, such as in Canada, AIDS is only diagnosed when a person infected with HIV is diagnosed with one or more of several AIDS-related opportunistic infections or cancers.<ref>[http://www.phac-aspc.gc.ca/publicat/haest-tesvs/a_e.html#AIDS_DIAGNOSIS Public Health Agency of Canada] (Note that this source is mistaken in its assertion that the U.S. definition of AIDS requires a CD4 count of <200.)</ref><ref>McGovern, Theresa and Smith, Raymond (1998). [http://www.thebody.com/content/art14002.html AIDS, Case Definition of.] TheBody.com. Retrieved on 2008-03-10.</ref><ref>[http://www.aegis.com/topics/definition.html AEGIS]</ref> [[Acute (medicine)|Acute]] HIV infection progresses over time to clinical latent HIV infection and then to early [[symptomatic]] HIV infection and later to AIDS, which is identified either on the basis of the amount of CD4<SUP>+</SUP> T cells in the blood, and/or the presence of certain infections, as noted above.
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| In the absence of [[Antiretroviral drug|antiretroviral therapy]], the median [[HIV Disease Progression Rates|time of progression from HIV infection to AIDS]] is nine to ten years, and the median survival time after developing AIDS is only 9.2 months.<ref name=Morgan2>{{
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| cite journal
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| | author=Morgan D, Mahe C, Mayanja B, Okongo JM, Lubega R, Whitworth JA
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| | title=HIV-1 infection in rural Africa: is there a difference in median time to AIDS and survival compared with that in industrialized countries?
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| | journal=AIDS | year=2002 | pages=597–632 | volume=16 | issue=4 | pmid=11873003
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| }}</ref> However, the rate of clinical disease progression varies widely between individuals, from two weeks up to 20 years. Many factors affect the rate of progression. These include factors that influence the body's ability to defend against HIV such as the infected person's general immune function.<ref name=Clerici>{{
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| cite journal
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| | author=Clerici M, Balotta C, Meroni L, et al | title=Type 1 cytokine production and low prevalence of viral isolation correlate with long-term non progression in HIV infection
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| | journal=AIDS Res. Hum. Retroviruses. | year=1996 | pages=1053–1061 | volume=12 | issue=11
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| | pmid=8827221
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| }}</ref><ref name=Morgan>{{
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| cite journal
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| | author=Morgan D, Mahe C, Mayanja B, Whitworth JA
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| | title=Progression to symptomatic disease in people infected with HIV-1 in rural Uganda: prospective cohort study
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| | journal=BMJ | year=2002 | pages=193–196 | volume=324 | issue=7331
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| | pmid=11809639 | doi=10.1136/bmj.324.7331.193
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| }}</ref> Older people have weaker immune systems, and therefore have a greater risk of rapid disease progression than younger people. Poor access to [[health care]] and the existence of coexisting infections such as [[tuberculosis]] also may predispose people to faster disease progression.<ref name=Morgan2 /><ref name=Gendelman>{{
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| cite journal
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| | author=Gendelman HE, Phelps W, Feigenbaum L, et al | title=Transactivation of the human immunodeficiency virus long terminal repeat sequences by DNA viruses
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| | journal=Proc. Natl. Acad. Sci. U. S. A. | year=1986 | pages=9759–9763 | volume=83 | issue=24
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| | pmid=2432602
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| }}</ref><ref name=Bentwich>{{
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| cite journal
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| | author=Bentwich Z, Kalinkovich, A, Weisman Z
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| | title=Immune activation is a dominant factor in the pathogenesis of African AIDS.
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| | journal=Immunol. Today | year=1995 | pages=187–191 | volume=16 | issue=4
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| | pmid=7734046
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| }}</ref> The infected person's [[genetics|genetic inheritance]] plays an important role and some people are resistant to certain strains of HIV. An example of this is people with the [[homozygous]] [[CCR5-Δ32]] variation are resistant to infection with certain [[strain (biology)|strains]] of HIV.<ref name=Tang>{{
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| cite journal
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| | author=Tang J, Kaslow RA
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| | title=The impact of host genetics on HIV infection and disease progression in the era of highly active antiretroviral therapy
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| | journal=AIDS | year=2003 | pages=S51–S60 | volume=17 | issue=Suppl 4
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| | pmid=15080180
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| }}</ref> HIV is genetically variable and exists as different strains, which cause different rates of clinical disease progression.<ref name=Quinones>{{
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| cite journal
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| | author=Quiñones-Mateu ME, Mas A, Lain de Lera T, Soriano V, Alcami J, Lederman MM, Domingo E
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| | title=LTR and tat variability of HIV-1 isolates from patients with divergent rates of disease progression
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| | journal=Virus Research | year=1998 | pages=11–20 | volume=57 | issue=1
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| | pmid=9833881
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| }}</ref><ref name=Campbell>{{
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| cite journal
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| | author=Campbell GR, Pasquier E, Watkins J, et al | title=The glutamine-rich region of the HIV-1 Tat protein is involved in T-cell apoptosis
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| | journal=J. Biol. Chem. | year=2004 | pages=48197–48204 | volume=279 | issue=46
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| | pmid=15331610 | doi=10.1074/jbc.M406195200
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| }}</ref><ref name=Kaleebu>{{
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| cite journal
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| | author=Kaleebu P, French N, Mahe C, et al | title=Effect of human immunodeficiency virus (HIV) type 1 envelope subtypes A and D on disease progression in a large cohort of HIV-1-positive persons in Uganda | journal=J. Infect. Dis. | year=2002 | pages=1244–1250 | volume=185 | issue=9
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| | pmid=12001041
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| }}</ref> The use of highly active antiretroviral therapy prolongs both the median time of progression to AIDS and the median survival time.
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| ===Alternative hypotheses===
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| {{main|AIDS reappraisal}}
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| A small minority of scientists and activists question the connection between HIV and AIDS,<ref name=Duesberg>{{cite journal
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| | author=Duesberg PH
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| | title=HIV is not the cause of AIDS
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| | journal=Science | year=1988 | pages=514, 517 | volume=241 | issue=4865
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| | pmid=3399880 | doi=10.1126/science.3399880
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| }}</ref> the existence of HIV itself,<ref name=Papadopulos>{{
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| cite journal
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| | author=Papadopulos-Eleopulos E, Turner VF, Papadimitriou J, et al
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| | title=A critique of the Montagnier evidence for the HIV/AIDS hypothesis
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| | journal=Med Hypotheses | year=2004 | pages=597–601 | volume=63 | issue=4
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| | pmid=15325002 | doi=10.1016/j.mehy.2004.03.025
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| }}</ref> or the validity of current testing and treatment methods. Though these claims have been examined and widely rejected by the scientific community,<ref name=consensus>For evidence of the [[scientific consensus]] that HIV is the cause of AIDS, see (for example):
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| *{{cite journal |title=The Durban Declaration |journal=Nature |volume=406 |issue=6791 |pages=15–6 |year=2000 |pmid=10894520 |doi=10.1038/35017662}} – full text [http://www.nature.com/nature/journal/v406/n6791/full/406015a0.html here].
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| *{{cite journal
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| | author=Cohen J
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| | title=The Controversy over HIV and AIDS
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| | journal=Science | year=1994 | pages=1642–1649 | volume=266 | issue=5191
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| | url=http://www.sciencemag.org/feature/data/cohen/266-5191-1642a.pdf|format=PDF}}
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| *{{cite web
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| | publisher=[[National Institute of Allergy and Infectious Diseases]] | year=
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| | url=http://www3.niaid.nih.gov/news/focuson/hiv/resources/
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| | title=Focus on the HIV-AIDS Connection: Resource links
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| | accessdate = 2006-09-07
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| }}
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| *{{cite journal |author=O'Brien SJ, Goedert JJ |title=HIV causes AIDS: Koch's postulates fulfilled |journal=Curr. Opin. Immunol. |volume=8 |issue=5 |pages=613-8 |year=1996 |pmid=8902385 |doi=}}
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| *{{cite journal |author=Galéa P, Chermann JC |title=HIV as the cause of AIDS and associated diseases |journal=Genetica |volume=104 |issue=2 |pages=133–42 |year=1998 |pmid=10220906 |doi=}}</ref> they continue to be promulgated through the Internet<ref>{{cite journal |author=Smith TC, Novella SP |title=HIV denial in the Internet era |journal=PLoS Med. |volume=4 |issue=8 |pages=e256 |year=2007 |pmid=17713982 |doi=10.1371/journal.pmed.0040256}}</ref> and have had a significant political impact, particularly in South Africa, where until late 2006 the Thabo Mbeki government did not accept that AIDS was caused by HIV, lead to an ineffective response to that country's AIDS epidemic.<ref>{{cite journal |author=Watson J |title=Scientists, activists sue South Africa's AIDS 'denialists' |journal=Nat. Med. |volume=12 |issue=1 |pages=6 |year=2006 |pmid=16397537 |doi=10.1038/nm0106-6a}}</ref><ref>{{cite journal |author=Baleta A |title=S Africa's AIDS activists accuse government of murder |journal=Lancet |volume=361 |issue=9363 |pages=1105 |year=2003 |pmid=12672319 |doi=10.1016/S0140-6736(03)12909-1}}</ref><ref>{{cite journal |author=Cohen J |title=South Africa's new enemy |journal=Science |volume=288 |issue=5474 |pages=2168-70 |year=2000 |pmid=10896606 |doi=10.1126/science.288.5474.2168}}</ref><ref>Andrew Meldrum. [http://www.guardian.co.uk/world/2006/oct/27/aids.southafrica South African government ends Aids denial], guardian.co.uk, 27 October 2006</ref>
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| ===Misconceptions===
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| {{main|HIV and AIDS misconceptions}}
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| A number of misconceptions have arisen surrounding HIV/AIDS. Three of the most common are that AIDS can spread through casual contact, that sexual intercourse with a virgin will cure AIDS, and that HIV can infect only homosexual men and drug users. Other misconceptions are that any act of anal intercourse between gay men can lead to AIDS infection, and that open discussion of homosexuality and HIV in schools will lead to increased rates of homosexuality and AIDS.<ref>{{cite book
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| |author=Blechner MJ
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| |title=Hope and mortality: psychodynamic approaches to AIDS and HIV
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| |publisher=Analytic Press
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| |location=Hillsdale, NJ
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| |year=1997
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| |isbn=0-88163-223-6
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| }}</ref>
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| ==Related Chapters==
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| [[Criminal transmission of HIV]]
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| ==References==
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| {{reflist|2}}
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