AIDS 5069516 226159824 2008-07-17T02:28:41Z RoyBoy 94806 /* Abzyme */ + {{pp-semi-protected|small=yes}} <!-- ATTENTION! PLEASE READ BEFORE EDITING! Please understand that this article is one of our most vandalized, and vandalism is reverted quickly. Persistent vandals of this page will most likely be blocked. If you wish to try test editing, you may do so in our sandbox located at: http://en.wikipedia.org/wiki/Wikipedia:Sandbox . Thanks! ************************************************************** --> {{otheruses}} {{Infobox_Disease | Name = Acquired immunodeficiency syndrome (AIDS) | Image = Red_Ribbon.svg | Caption = The [[Red ribbon#AIDS awareness symbol|Red ribbon]] is a symbol for solidarity with HIV-positive people and those living with AIDS. | Width = 120 | DiseasesDB = 5938 | ICD10 = {{ICD10|B|24||b|20}} | ICD9 = {{ICD9|042}} | ICDO = | OMIM = | MedlinePlus = 000594 | eMedicineSubj = emerg | eMedicineTopic = 253 | MeshID = D000163 | }} {| style="float: right; clear:right; margin: 0 0 0.5em 1em; padding: 0.5em; background: #fffff4; border: 1px solid #ddb; width: 250px; font-size:90%;" |- |List of abbreviations used in this article<br> '''AIDS''': Acquired immune deficiency syndrome<br> '''HIV''': [[Human immunodeficiency virus]]<br> '''CD4+''': [[T helper cells]] <br> '''CCR5''': [[Chemokine (C-C motif) receptor 5]]<br> '''CDC''': [[Centers for Disease Control and Prevention]]<br> '''WHO''': [[World Health Organization]]<br> '''PCP''': [[Pneumocystis pneumonia]]<br> '''TB''': [[Tuberculosis]]<br> '''MTCT''': Mother-to-child transmission<br> '''HAART''': [[Highly active antiretroviral therapy]]<br> '''STI/STD''': [[Sexually transmitted infection]]/disease |} '''Acquired immune deficiency syndrome ''' or '''acquired immunodeficiency syndrome''' ('''AIDS''' or '''Aids''') is a [[syndrome|set of symptoms and infections]] resulting from the damage to the human [[immune system]] caused by the [[HIV|human immunodeficiency virus]] (HIV).<ref>{{cite journal |author=Weiss RA |title=How does HIV cause AIDS? |journal=Science (journal) |volume=260 |issue=5112 |pages=1273–9 |year=1993 |month=May |pmid=8493571 |doi= |url= }}</ref> This condition progressively reduces the effectiveness of the immune system and leaves individuals susceptible to [[opportunistic infection]]s and [[tumor]]s. HIV is [[Transmission (medicine)|transmitted]] through direct contact of a [[mucous membrane]] or the bloodstream with a [[bodily fluid]] containing HIV, such as [[blood]], [[semen]], [[vaginal fluid]], [[preseminal fluid]], and [[breast milk]].<!-- And NOT through body fluids like saliva and tears, see references--><ref name=CDCtransmission>{{ cite web | author=[[Divisions of HIV/AIDS Prevention]] | publisher=[[Centers for Disease Control & Prevention]] | year= 2003 | url=http://www.cdc.gov/HIV/pubs/facts/transmission.htm | title=HIV and Its Transmission | accessdate = 2006-05-23 }}</ref><ref name=sfaf>{{ cite web | author=[[San Francisco AIDS Foundation]] | publisher= | year= [[2006-04-14]] | url=http://www.sfaf.org/aids101/transmission.html | title=How HIV is spread | accessdate = 2006-05-23 }}</ref> This transmission can involve [[anal sex|anal]], [[vaginal sex|vaginal]] or [[oral sex|oral]] [[Sexual intercourse|sex]], [[blood transfusion]], contaminated [[hypodermic needle]]s, exchange between mother and baby during [[pregnancy]], [[childbirth]], or [[breastfeeding]], or other exposure to one of the above bodily fluids. AIDS is now a [[pandemic]].<ref name=Kallings/> In 2007, an estimated 33.2&nbsp;million people lived with the disease worldwide, and it killed an estimated 2.1&nbsp;million people, including 330,000 children.<ref name=UNAIDS2007/> Over three-quarters of these deaths occurred in sub-Saharan Africa,<ref name=UNAIDS2007/> retarding [[economic growth]] and destroying [[human capital]].<ref name=Bell-et-al-2003/> Most researchers believe that HIV originated in [[sub-Saharan Africa]] during the twentieth century.<ref name=Gao> {{ cite journal | author=Gao F, Bailes E, Robertson DL, et al | title=Origin of HIV-1 in the Chimpanzee Pan troglodytes troglodytes | journal=Nature | year=1999 | pages=436&ndash;441 | volume=397 | issue=6718 | pmid=9989410 |doi=10.1038/17130 }}</ref> The disease was first identified by the U.S. [[Centers for Disease Control and Prevention]] in 1981 and its cause identified by American and French scientists in the late 1980s.<ref>{{cite journal |author=Gallo RC |title=A reflection on HIV/AIDS research after 25 years |journal=Retrovirology |volume=3 |issue= |pages=72 |year=2006 |pmid=17054781 |doi=10.1186/1742-4690-3-72 |url=http://www.retrovirology.com/content/3//72}}</ref> Although treatments for AIDS and HIV can slow the course of the disease, there is currently no vaccine or cure. [[antiretroviral drug|Antiretroviral]] treatment reduces both the [[Mortality rate|mortality]] and the morbidity of HIV infection, but these drugs are expensive and routine access to antiretroviral [[medication]] is not available in all countries.<ref name=Palella>{{ cite journal | author=Palella FJ Jr, Delaney KM, Moorman AC, et al | title=Declining morbidity and mortality among patients with advanced human immunodeficiency virus infection. HIV Outpatient Study Investigators | journal=N. Engl. J. Med | year=1998 | pages=853&ndash;860 | volume=338 | issue=13 | pmid=9516219 }}</ref> Due to the difficulty in treating HIV infection, preventing infection is a key aim in controlling the AIDS epidemic, with health organizations promoting [[safe sex]] and [[needle-exchange programme]]s in attempts to slow the spread of the virus. ==Symptoms== [[Image:Hiv-timecourse.png|450px|thumb|right|A generalized graph of the relationship between HIV copies (viral load) and CD4 counts over the average course of untreated HIV infection; any particular individual's disease course may vary considerably. {{legend-line|blue solid 2px|CD4<sup>+</sup> T Lymphocyte count (cells/mm³)}} {{legend-line|red solid 2px|HIV RNA copies per mL of plasma}} ]] The symptoms of AIDS are primarily the result of conditions that do not normally develop in individuals with healthy [[immune system]]s. Most of these conditions are infections caused by [[bacteria]], [[virus]]es, [[fungus|fungi]] and [[parasite]]s that are normally controlled by the elements of the immune system that HIV damages. [[Opportunistic infection]]s are common in people with AIDS.<ref name=Holmes>{{ cite journal | author=Holmes CB, Losina E, Walensky RP, Yazdanpanah Y, Freedberg KA | title=Review of human immunodeficiency virus type 1-related opportunistic infections in sub-Saharan Africa | journal=Clin. Infect. Dis. | year=2003 | pages=656&ndash;662 | volume=36 | issue=5 | pmid=12594648 }}</ref> HIV affects nearly every [[organ system]]. People with AIDS also have an increased risk of developing various cancers such as [[Kaposi's sarcoma]], [[cervical cancer]] and cancers of the immune system known as [[lymphoma]]s. Additionally, people with AIDS often have systemic symptoms of infection like [[fever]]s, [[sweat]]s (particularly at night), swollen glands, chills, weakness, and [[weight loss]].<ref name=Guss>{{ cite journal | author=Guss DA | title=The acquired immune deficiency syndrome: an overview for the emergency physician, Part 1 | journal=J. Emerg. Med. | year=1994 | pages=375&ndash;384 | volume=12 | issue=3 | pmid=8040596 }}</ref><ref name=Guss2>{{ cite journal | author=Guss DA | title=The acquired immune deficiency syndrome: an overview for the emergency physician, Part 2 | journal=J. Emerg. Med. | year=1994 | pages=491&ndash;497 | volume=12 | issue=4 | pmid=7963396 }}</ref> The specific opportunistic infections that AIDS patients develop depend in part on the prevalence of these infections in the geographic area in which the patient lives. ===Pulmonary infections=== [[Image:PCPxray.jpg|thumb|right|150px|X-ray of [[Pneumocystis pneumonia (PCP)|''Pneumocystis jirovecii'']] caused pneumonia. There is increased white (opacity) in the lower lungs on both sides, characteristic of ''Pneumocystis'' pneumonia]] [[Pneumocystis pneumonia (PCP)|Pneumocystis pneumonia]] (originally known as ''Pneumocystis carinii'' pneumonia, and still abbreviated as PCP, which now stands for '''P'''neumo'''c'''ystis '''p'''neumonia) is relatively rare in healthy, [[immunocompetent]] people, but common among HIV-infected individuals. It is caused by [[Pneumocystis pneumonia (PCP)|''Pneumocystis jirovecii'']]. Before the advent of effective diagnosis, treatment and routine [[prophylaxis]] in Western countries, it was a common immediate cause of death. In developing countries, it is still one of the first indications of AIDS in untested individuals, although it does not generally occur unless the CD4 count is less than 200 cells per µL of blood.<ref name=Feldman>{{ cite journal | author=Feldman C | title=Pneumonia associated with HIV infection | journal=Curr. Opin. Infect. Dis. | year=2005 | pages=165&ndash;170 | volume=18 | issue=2 | pmid=15735422 }}</ref> [[Tuberculosis]] (TB) is unique among infections associated with HIV because it is transmissible to immunocompetent people via the respiratory route, is easily treatable once identified, may occur in early-stage HIV disease, and is preventable with drug therapy. However, [[multidrug resistance]] is a potentially serious problem. Even though its incidence has declined because of the use of directly observed therapy and other improved practices in Western countries, this is not the case in developing countries where HIV is most prevalent. In early-stage HIV infection (CD4 count >300 cells per µL), TB typically presents as a pulmonary disease. In advanced HIV infection, TB often presents atypically with extrapulmonary (systemic) disease a common feature. Symptoms are usually constitutional and are not localized to one particular site, often affecting [[bone marrow]], [[bone]], urinary and [[gastrointestinal tract]]s, [[liver]], regional [[lymph node]]s, and the [[central nervous system]].<ref name=Decker>{{ cite journal | author=Decker CF, Lazarus A | title=Tuberculosis and HIV infection. How to safely treat both disorders concurrently | journal=Postgrad Med. | year=2000 | pages=57&ndash;60, 65&ndash;68 | volume=108 | issue=2 | pmid=10951746 }}</ref> ===Gastrointestinal infections=== [[Esophagitis]] is an inflammation of the lining of the lower end of the [[esophagus]] (gullet or swallowing tube leading to the [[stomach]]). In HIV infected individuals, this is normally due to fungal ([[candidiasis]]) or viral ([[Herpes simplex virus|herpes simplex-1]] or [[cytomegalovirus]]) infections. In rare cases, it could be due to [[mycobacteria]].<ref name=Zaidi>{{ cite journal | author=Zaidi SA, Cervia JS | title=Diagnosis and management of infectious esophagitis associated with human immunodeficiency virus infection | journal=J. Int. Assoc. Physicians AIDS Care (Chic Ill) | year=2002 | pages=53&ndash;62 | volume=1 | issue=2 | pmid=12942677 }}</ref> Unexplained chronic [[diarrhea]] in HIV infection is due to many possible causes, including common bacterial (''[[Salmonella]]'', ''[[Shigella]]'', ''[[Listeria]]'' or ''[[Campylobacter]]'') and parasitic infections; and uncommon opportunistic infections such as [[cryptosporidiosis]], [[microsporidiosis]], ''[[Mycobacterium avium]]'' complex (MAC) and viruses,<ref name="pmid11444032">{{cite journal |author=Pollok RC |title=Viruses causing diarrhoea in AIDS |journal=Novartis Found. Symp. |volume=238 |issue= |pages=276–83; discussion 283–8 |year=2001 |pmid=11444032 |doi= |url= }}</ref> [[astrovirus]], [[adenovirus]], [[rotavirus]] and [[cytomegalovirus]], (the latter as a course of [[colitis]]). In some cases, diarrhea may be a side effect of several drugs used to treat HIV, or it may simply accompany HIV infection, particularly during primary HIV infection. It may also be a side effect of [[antibiotic]]s used to treat bacterial causes of diarrhea (common for ''[[Clostridium difficile]]''). In the later stages of HIV infection, diarrhea is thought to be a reflection of changes in the way the [[intestinal tract]] absorbs nutrients, and may be an important component of HIV-related [[wasting]].<ref name=Guerrant>{{ cite journal | author=Guerrant RL, Hughes JM, Lima NL, Crane J | title=Diarrhea in developed and developing countries: magnitude, special settings, and etiologies | journal=Rev. Infect. Dis. | year=1990 | pages=S41&ndash;S50 | volume=12 | issue=Suppl 1 | pmid=2406855 }}</ref> ===Neurological and psychiatric involvement=== HIV infection may lead to a variety of neuropsychiatric sequelae, either by infection of the now susceptible nervous system by organisms, or as a direct consequence of the illness itself. [[Toxoplasmosis]] is a disease caused by the single-celled [[parasite]] called ''Toxoplasma gondii''; it usually infects the brain causing toxoplasma [[encephalitis]] but it can infect and cause disease in the [[eye]]s and lungs.<ref name=Luft>{{cite journal | author=Luft BJ, Chua A | title=Central Nervous System Toxoplasmosis in HIV Pathogenesis, Diagnosis, and Therapy | journal=Curr. Infect. Dis. Rep. | year=2000 | pages=358&ndash;362 | volume=2 | issue=4 | pmid=11095878 }}</ref> Cryptococcal meningitis is an infection of the [[meninges|meninx]] (the membrane covering the brain and [[spinal cord]]) by the fungus ''[[Cryptococcus neoformans]]''. It can cause fevers, [[headache]], [[Fatigue (medical)|fatigue]], [[nausea]], and [[vomiting]]. Patients may also develop [[seizure]]s and confusion; left untreated, it can be lethal. [[Progressive multifocal leukoencephalopathy]] (PML) is a [[demyelinating disease]], in which the gradual destruction of the [[myelin]] sheath covering the [[axon]]s of nerve cells impairs the transmission of nerve impulses. It is caused by a virus called [[JC virus]] which occurs in 70% of the population in [[Virus latency|latent]] form, causing disease only when the immune system has been severely weakened, as is the case for AIDS patients. It progresses rapidly, usually causing death within months of diagnosis.<ref name=Sadler>{{ cite journal | author=Sadler M, Nelson MR | title=Progressive multifocal leukoencephalopathy in HIV | journal=Int. J. STD AIDS | year=1997 | pages=351&ndash;357 | volume=8 | issue=6 | pmid=9179644}}</ref> [[AIDS dementia complex]] (ADC) is a metabolic [[encephalopathy]] induced by HIV infection and fueled by immune activation of HIV infected brain [[macrophage]]s and [[microglia]] which secrete [[neurotoxin]]s of both host and viral origin.<ref name=Gray>{{ cite journal | author=Gray F, Adle-Biassette H, Chrétien F, Lorin de la Grandmaison G, Force G, Keohane C | title=Neuropathology and neurodegeneration in human immunodeficiency virus infection. Pathogenesis of HIV-induced lesions of the brain, correlations with HIV-associated disorders and modifications according to treatments | journal=Clin. Neuropathol. | year=2001 | pages=146&ndash;155 | volume=20 | issue=4 | pmid=11495003 }}</ref> Specific neurological impairments are manifested by cognitive, behavioral, and motor abnormalities that occur after years of HIV infection and is associated with low CD4<SUP>+</SUP> T cell levels and high plasma viral loads. Prevalence is 10&ndash;20% in Western countries<ref name=Grant>{{ cite book | author = Grant I, Sacktor H, McArthur J | year = 2005 | title = The Neurology of AIDS | chapter = HIV neurocognitive disorders | chapterurl = http://www.hnrc.ucsd.edu/publications_pdf/2005grant1.pdf | editor = H. E. Gendelman, I. Grant, I. Everall, S. A. Lipton, and S. Swindells. (ed.) | edition = 2nd | pages = 357&ndash;373 | publisher = Oxford University Press | location = London, UK | format= PDF | id = ISBN 0-19-852610-5 }}</ref> but only 1&ndash;2% of HIV infections in [[India]].<ref name=Satischandra>{{ cite journal | author=Satishchandra P, Nalini A, Gourie-Devi M, et al | title=Profile of neurologic disorders associated with HIV/AIDS from Bangalore, South India (1989&ndash;1996) | journal=Indian J. Med. Res. | year=2000 | pages=14&ndash;23 | volume=11 | issue= | pmid=10793489 }}</ref><ref name=Wadia>{{ cite journal | author=Wadia RS, Pujari SN, Kothari S, Udhar M, Kulkarni S, Bhagat S, Nanivadekar A | title=Neurological manifestations of HIV disease | journal=J. Assoc. Physicians India | year=2001 | pages=343&ndash;348 | volume=49 | issue= | pmid=11291974 }}</ref> This difference is possibly due to the HIV subtype in [[India]]. AIDS related mania is sometimes seen in patients with advanced HIV illness; it presents with more irritability and cognitive impairment and less euphoria than a [[manic episode]] associated with true [[bipolar disorder]]. Unlike the latter condition, it may have a more chronic course. This syndrome is less often seen with the advent of multi-drug therapy. ===Tumors and malignancies=== [[Image:Kaposi's Sarcoma.jpg|thumb|right|150px|Kaposi's sarcoma]] Patients with HIV infection have substantially increased incidence of several malignant [[cancer]]s. This is primarily due to co-infection with an [[oncogene|oncogenic]] [[DNA virus]], especially [[Epstein-Barr virus]] (EBV), Kaposi's sarcoma-associated herpesvirus ([[KSHV]]), and human [[papillomavirus]] (HPV).<ref name=Boshoff>{{ cite journal | author=Boshoff C, Weiss R | title=AIDS-related malignancies | journal=Nat. Rev. Cancer | year=2002 | pages=373&ndash;382 | volume=2 | issue=5 | pmid=12044013 }}</ref><ref name=Yarchoan>{{ cite journal | author=Yarchoan R, Tosatom G, Littlem RF | title=Therapy insight: AIDS-related malignancies &mdash; the influence of antiviral therapy on pathogenesis and management | journal=Nat. Clin. Pract. Oncol. | year=2005 | pages=406&ndash;415 | volume=2 | issue=8 | pmid=16130937 }}</ref> Kaposi's sarcoma (KS) is the most common tumor in HIV-infected patients. The appearance of this tumor in young homosexual men in 1981 was one of the first signals of the AIDS epidemic. Caused by a [[Gammaherpesvirinae|gammaherpes]] virus called [[Kaposi's sarcoma-associated herpes virus]] (KSHV), it often appears as purplish [[Nodule (medicine)|nodules]] on the skin, but can affect other organs, especially the [[mouth]], gastrointestinal tract, and lungs. High-grade [[B cell]] [[lymphoma]]s such as [[Burkitt's lymphoma]], Burkitt's-like lymphoma, diffuse large B-cell lymphoma (DLBCL), and [[primary central nervous system lymphoma]] present more often in HIV-infected patients. These particular cancers often foreshadow a poor prognosis. In some cases these lymphomas are AIDS-defining. [[Epstein-Barr virus]] (EBV) or KSHV cause many of these lymphomas. [[Cervical cancer]] in HIV-infected women is considered AIDS-defining. It is caused by [[human papillomavirus]] (HPV).<ref>{{cite journal |author=Palefsky J |title=Human papillomavirus infection in HIV-infected persons |journal=Top HIV Med |volume=15 |issue=4 |pages=130–3 |year=2007 |pmid=17720998 |doi= }}</ref> In addition to the AIDS-defining tumors listed above, HIV-infected patients are at increased risk of certain other tumors, such as [[Hodgkin's disease]] and [[Anal cancer|anal]] and [[rectal carcinoma]]s. However, the incidence of many common tumors, such as [[breast cancer]] or [[colon cancer]], does not increase in HIV-infected patients. In areas where [[HAART]] is extensively used to treat AIDS, the incidence of many AIDS-related malignancies has decreased, but at the same time malignant cancers overall have become the most common cause of death of HIV-infected patients.<ref name=Bonnet>{{ cite journal | author=Bonnet F, Lewden C, May T, et al | title=Malignancy-related causes of death in human immunodeficiency virus-infected patients in the era of highly active antiretroviral therapy | journal=Cancer | year=2004 | pages=317&ndash;324 | volume=101 | issue=2 | pmid=15241829 }}</ref> ===Other opportunistic infections=== AIDS patients often develop opportunistic infections that present with non-specific symptoms, especially [[low-grade fever]]s and weight loss. These include infection with ''[[Mycobacterium avium]]-intracellulare'' and [[cytomegalovirus]] (CMV). CMV can cause colitis, as described above, and [[Cytomegalovirus retinitis|CMV retinitis]] can cause [[blindness]]. [[Penicilliosis]] due to ''[[Penicillium marneffei]]'' is now the third most common opportunistic infection (after extrapulmonary tuberculosis and [[cryptococcosis]]) in HIV-positive individuals within the endemic area of [[Southeast Asia]].<ref name=Skoulidis>{{ cite journal | author=Skoulidis F, Morgan MS, MacLeod KM | title=Penicillium marneffei: a pathogen on our doorstep? | journal=J. R. Soc. Med.| year=2004 | pages=394&ndash;396 | volume=97 | issue=2 | pmid=15286196 }}</ref> ==Cause== {{details|HIV}} [[Image:HIV-budding-Color.jpg|right|thumbnail|300px|[[Scanning electron microscope|Scanning electron micrograph]] of HIV-1, colored green, budding from a cultured [[lymphocyte]].]] 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>{{ cite journal | author=Alimonti JB, Ball TB, Fowke KR | title=Mechanisms of CD4+ T lymphocyte cell death in human immunodeficiency virus infection and AIDS. | journal=J. Gen. Virol. | year=2003 | pages=1649&ndash;1661 | volume=84 | issue=7 | pmid=12810858 | doi=10.1099/vir.0.19110-0 }}</ref> Once HIV has killed so many CD4<SUP>+</SUP> T cells that there are fewer than 200 of these cells per [[microliter]] (µL) of [[blood]], [[cellular immunity]] is lost. [[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 remaining in the blood, and/or the presence of certain infections, as noted above.<ref name="Differential diagnosis">{{cite book |author= |title=An Atlas of Differential Diagnosis in HIV Disease, Second Edition |publisher=CRC Press-Parthenon Publishers |location= |year=2003 |pages=22-27 |isbn=1-84214-026-4 |oclc= |doi= }}</ref> 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>{{ cite journal | author=Morgan D, Mahe C, Mayanja B, Okongo JM, Lubega R, Whitworth JA | title=HIV-1 infection in rural Africa: is there a difference in median time to AIDS and survival compared with that in industrialized countries? | journal=AIDS | year=2002 | pages=597&ndash;632 | volume=16 | issue=4 | pmid=11873003 }}</ref> However, the rate of clinical disease progression varies widely between individuals, from two weeks up to 20&nbsp;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>{{ cite journal | 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 | journal=AIDS Res. Hum. Retroviruses. | year=1996 | pages=1053&ndash;1061 | volume=12 | issue=11 | pmid=8827221 }}</ref><ref name=Morgan>{{ cite journal | author=Morgan D, Mahe C, Mayanja B, Whitworth JA | title=Progression to symptomatic disease in people infected with HIV-1 in rural Uganda: prospective cohort study | journal=BMJ | year=2002 | pages=193&ndash;196 | volume=324 | issue=7331 | pmid=11809639 | doi=10.1136/bmj.324.7331.193 }}</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>{{ cite journal | author=Gendelman HE, Phelps W, Feigenbaum L, et al | title=Transactivation of the human immunodeficiency virus long terminal repeat sequences by DNA viruses | journal=Proc. Natl. Acad. Sci. U. S. A. | year=1986 | pages=9759&ndash;9763 | volume=83 | issue=24 | pmid=2432602 }}</ref><ref name=Bentwich>{{ cite journal | author=Bentwich Z, Kalinkovich, A, Weisman Z | title=Immune activation is a dominant factor in the pathogenesis of African AIDS. | journal=Immunol. Today | year=1995 | pages=187&ndash;191 | volume=16 | issue=4 | pmid=7734046 }}</ref> The infected person's [[genetics|genetic inheritance]] plays an important role and some people are [[resistance (biology)|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>{{ cite journal | author=Tang J, Kaslow RA | title=The impact of host genetics on HIV infection and disease progression in the era of highly active antiretroviral therapy | journal=AIDS | year=2003 | pages=S51&ndash;S60 | volume=17 | issue=Suppl 4 | pmid=15080180 }}</ref> HIV is genetically variable and exists as different strains, which cause different rates of clinical disease progression.<ref name=Quinones>{{ cite journal | author=Quiñones-Mateu ME, Mas A, Lain de Lera T, Soriano V, Alcami J, Lederman MM, Domingo E | title=LTR and tat variability of HIV-1 isolates from patients with divergent rates of disease progression | journal=Virus Research | year=1998 | pages=11&ndash;20 | volume=57 | issue=1 | pmid=9833881 }}</ref><ref name=Campbell>{{ cite journal | 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 | journal=J. Biol. Chem. | year=2004 | pages=48197&ndash;48204 | volume=279 | issue=46 | pmid=15331610 | doi=10.1074/jbc.M406195200 }}</ref><ref name=Kaleebu>{{ cite journal | 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&ndash;1250 | volume=185 | issue=9 | pmid=12001041 }}</ref> ===Sexual transmission=== Sexual transmission occurs with the contact between sexual secretions of one person with the rectal, genital or oral [[mucous membrane]]s of another. Unprotected receptive sexual acts are riskier than unprotected insertive sexual acts, and the risk for transmitting HIV through unprotected anal intercourse is greater than the risk from vaginal intercourse or oral sex. However, oral sex is not entirely safe, as HIV can be transmitted through both insertive and receptive oral sex.<ref name=Rothenberg>{{ cite journal | author=Rothenberg RB, Scarlett M, del Rio C, Reznik D, O'Daniels C | title=Oral transmission of HIV | journal=AIDS | year=1998 | pages=2095&ndash;2105 | volume=12 | issue=16 | pmid=9833850 }}</ref> The risk of HIV transmission from exposure to [[saliva]] is considerably smaller than the risk from exposure to [[semen]], one would have to swallow liters of saliva from a carrier to run a significant risk of becoming infected.<ref name=Vincenzi>{{ cite journal | author=Mastro TD, de Vincenzi I | title=Probabilities of sexual HIV-1 transmission | journal=AIDS | year=1996 | volume=10 | pages=S75&ndash;S82 | issue=Suppl A | pmid=8883613 }}</ref> Sexual assault greatly increases the risk of HIV transmission as protection is rarely employed and physical trauma to the vagina frequently occurs, facilitating the transmission of HIV.<ref>{{cite journal |author=Koenig MA, Zablotska I, Lutalo T, Nalugoda F, Wagman J, Gray R |title=Coerced first intercourse and reproductive health among adolescent women in Rakai, Uganda |journal=Int Fam Plan Perspect |volume=30 |issue=4 |pages=156–63 |year=2004 |pmid=15590381 |doi=10.1363/ifpp.30.156.04 }}</ref> Other [[sexually transmitted infection]]s (STI) increase the risk of HIV transmission and infection, because they cause the disruption of the normal [[epithelial]] barrier by genital [[ulcer]]ation and/or microulceration; and by accumulation of pools of HIV-susceptible or HIV-infected cells ([[lymphocyte]]s and [[macrophage]]s) in semen and vaginal secretions. Epidemiological studies from sub-Saharan Africa, [[Europe]] and [[North America]] suggest that genital ulcers, such as those caused by [[syphilis]] and/or [[chancroid]], increase the risk of becoming infected with HIV by about four-fold. There is also a significant although lesser increase in risk from STIs such as [[gonorrhea]], [[Chlamydia infection|Chlamydial infection]] and [[trichomoniasis]], which all cause local accumulations of lymphocytes and macrophages.<ref name=Laga>{{ cite journal | author=Laga M, Nzila N, Goeman J | title=The interrelationship of sexually transmitted diseases and HIV infection: implications for the control of both epidemics in Africa | journal=AIDS | year=1991 | pages=S55&ndash;S63 | volume=5 | issue=Suppl 1 | pmid=1669925 }}</ref> Transmission of HIV depends on the infectiousness of the [[index case]] and the susceptibility of the uninfected partner. Infectivity seems to vary during the course of illness and is not constant between individuals. An undetectable plasma [[viral load]] does not necessarily indicate a low viral load in the seminal liquid or genital secretions. However, each 10-fold increase in the level of HIV in the blood is associated with an 81% increased rate of HIV transmission.<ref name=Laga /><ref name=Tovanabutra>{{ cite journal | author=Tovanabutra S, Robison V, Wongtrakul J, et al | title=Male viral load and heterosexual transmission of HIV-1 subtype E in northern Thailand | journal=J. Acquir. Immune. Defic. Syndr. | year=2002 | pages=275&ndash;283 | volume=29 | issue=3 | pmid=11873077 }}</ref> Women are more susceptible to HIV-1 infection due to hormonal changes, vaginal microbial ecology and physiology, and a higher prevalence of sexually transmitted diseases.<ref name=Sagar>{{ cite journal | author=Sagar M, Lavreys L, Baeten JM, et al | title=Identification of modifiable factors that affect the genetic diversity of the transmitted HIV-1 population | journal=AIDS | year=2004 | pages=615&ndash;619 | volume=18 | issue=4 | pmid=15090766 }}</ref><ref name=Lavreys>{{cite journal |author=Lavreys L, Baeten JM, Martin HL, ''et al'' |title=Hormonal contraception and risk of HIV-1 acquisition: results of a 10-year prospective study |journal=AIDS |volume=18 |issue=4 |pages=695–7 |year=2004 |month=March |pmid=15090778 }}</ref> People who have been infected with one strain of HIV can still be infected later on in their lives by other, more [[virulent]] strains. Infection is unlikely in a single encounter. High rates of infection have been linked to a pattern of overlapping long-term romantic relationships. This allows the virus to quickly spread to multiple partners who in turn infect their partners. A pattern of serial monogamy or occasional casual encounters is associated with lower rates of infection.<ref>{{cite book |author=Epstein, Helen |title=The invisible cure: Africa, the West, and the fight against AIDS |publisher=Farrar, Straus, and Giroux |location=New York |year=2007 |pages= |isbn=0-374-28152-1 |oclc= |doi= |accessdate= }}</ref> ===Exposure to blood-borne pathogens=== [[Image:AIDS Poster If You're Dabbling in Drugs 1989.jpg|thumb|250px|CDC poster from 1989 highlighting the threat of AIDS associated with drug use]] This transmission route is particularly relevant to [[Intravenous drug use (recreational)|intravenous drug]] users, [[Haemophilia|hemophiliacs]] and recipients of [[blood transfusion]]s and blood products. Sharing and reusing [[syringe]]s contaminated with HIV-infected blood represents a major risk for infection with HIV. Needle sharing is the cause of one third of all new HIV-infections in [[North America]], [[China]], and [[Eastern Europe]]. The risk of being infected with HIV from a single prick with a needle that has been used on an HIV-infected person is thought to be about 1 in 150 ([[AIDS#Transmission and prevention|see table above]]). [[Post-exposure prophylaxis]] with anti-HIV drugs can further reduce this risk.<ref name=Fan>{{ cite book | author =Fan H | year = 2005 | title =AIDS: science and society | chapterurl = | editor = Fan, H., Conner, R. F. and Villarreal, L. P. eds | edition = 4th | pages = | publisher =Jones and Bartlett Publishers | location = Boston, MA | id = ISBN 0-7637-0086-X }}</ref> This route can also affect people who give and receive [[tattoo]]s and [[Body piercing|piercings]]. [[Universal precautions]] are frequently not followed in both sub-Saharan Africa and much of Asia because of both a shortage of supplies and inadequate training. The WHO estimates that approximately 2.5% of all HIV infections in sub-Saharan Africa are transmitted through unsafe healthcare injections.<ref name=WHOJapan>{{ cite web | publisher=[[World Health Organization|WHO]]| date= 2003-03-17 | url=http://64.233.179.104/search?q=cache:adH68_6JGG8J:tokyo.usembassy.gov//e/p/tp-20030317a3.html+site:tokyo.usembassy.gov+HIV+healthcare+injection&hl=en&gl=us&ct=clnk&cd=1 | title=WHO, UNAIDS Reaffirm HIV as a Sexually Transmitted Disease | accessdate = 2006-01-17 }}</ref> Because of this, the [[United Nations General Assembly]] has urged the nations of the world to implement precautions to prevent HIV transmission by health workers.<ref>{{cite web |url=http://data.unaids.org/pub/Report/2007/20070925_advocacy_grne2_en.pdf |title= Financial Resources Required to Achieve, Universal Access to HIV Prevention, Treatment Care and Support |accessdate=2008-04-11 |publisher=UNAIDS |format=pdf |work= }}</ref> The risk of transmitting HIV to [[blood transfusion]] recipients is extremely low in developed countries where improved donor selection and HIV screening is performed. However, according to the [[World Health Organization|WHO]], the overwhelming majority of the world's population does not have access to safe blood and between 5% and 10% of the world's HIV infections come from transfusion of infected blood and blood products.<ref name=WHO070401>{{ cite web | publisher=[[World Health Organization|WHO]] | year= 2001 | url=http://www.who.int/inf-pr-2000/en/pr2000-25.html | title=Blood safety....for too few | accessdate = 2006-01-17 }}</ref> ===Perinatal transmission=== The transmission of the virus from the mother to the child can occur ''[[in utero]]'' during the last weeks of pregnancy and at childbirth. In the absence of treatment, the transmission rate between a mother and her child during pregnancy, labor and delivery is 25%. However, when the mother takes antiretroviral therapy and gives birth by [[caesarean section]], the rate of transmission is just 1%.<ref name=Coovadia /> The risk of infection is influenced by the viral load of the mother at birth, with the higher the viral load, the higher the risk. [[Breastfeeding]] also increases the risk of transmission by about 4 %.<ref name=Coovadia2>{{ cite journal | author=Coovadia HM, Bland RM| title=Preserving breastfeeding practice through the HIV pandemic | journal=Trop. Med. Int. Health. | year=2007| pages=1116&ndash;1133 | volume=12 | issue=9 | pmid=17714431 }}</ref> ===Misconceptions=== {{main|HIV and AIDS misconceptions}} 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 |author=Blechner MJ |title=Hope and mortality: psychodynamic approaches to AIDS and HIV |publisher=Analytic Press |location=Hillsdale, NJ |year=1997 |isbn=0-88163-223-6 }}</ref> ==Pathophysiology== {{Cleanup-section|date=April 2008}} The pathophysiology of AIDS is complex, as is the case with all [[syndrome]]s.<ref name="pmid8040596">{{cite journal |author=Guss DA |title=The acquired immune deficiency syndrome: an overview for the emergency physician, Part 1 |journal=J Emerg Med |volume=12 |issue=3 |pages=375–84 |year=1994 |pmid=8040596 |doi= }}</ref> Ultimately, HIV causes AIDS by depleting CD4<sup>+</sup> T helper lymphocytes. This weakens the immune system and allows [[opportunistic infection]]s. T lymphocytes are essential to the immune response and without them, the body cannot fight infections or kill cancerous cells. The mechanism of CD4<sup>+</sup> T cell depletion differs in the acute and chronic phases.<ref name="pmid16679064">{{cite journal |author=Hel Z, McGhee JR, Mestecky J |title=HIV infection: first battle decides the war |journal=Trends Immunol. |volume=27 |issue=6 |pages=274–81 |year=2006 |month=June |pmid=16679064 |doi=10.1016/j.it.2006.04.007 |url=}}</ref> During the acute phase, HIV-induced cell lysis and killing of infected cells by [[cytotoxic T cells]] accounts for CD4<sup>+</sup> T cell depletion, although [[apoptosis]] may also be a factor. During the chronic phase, the consequences of generalized immune activation coupled with the gradual loss of the ability of the immune system to generate new T cells appear to account for the slow decline in CD4<sup>+</sup> T cell numbers. Although the symptoms of immune deficiency characteristic of AIDS do not appear for years after a person is infected, the bulk of CD4<sup>+</sup> T cell loss occurs during the first weeks of infection, especially in the intestinal mucosa, which harbors the majority of the lymphocytes found in the body. <ref name="pmid15365095">{{cite journal |author=Mehandru S, Poles MA, Tenner-Racz K, Horowitz A, Hurley A, Hogan C, Boden D, Racz P, Markowitz M |title=Primary HIV-1 infection is associated with preferential depletion of CD4<sup>+</sup> T lymphocytes from effector sites in the gastrointestinal tract |journal=J. Exp. Med. |volume=200 |issue=6 |pages=761–70 |year=2004 |month=September |pmid=15365095 |doi=10.1084/jem.20041196 |url=}}</ref> The reason for the preferential loss of mucosal CD4<sup>+</sup> T cells is that a majority of mucosal CD4<sup>+</sup> T cells express the CCR5 coreceptor, whereas a small fraction of CD4<sup>+</sup> T cells in the bloodstream do so.<ref name="pmid15365096">{{cite journal |author=Brenchley JM, Schacker TW, Ruff LE, Price DA, Taylor JH, Beilman GJ, Nguyen PL, Khoruts A, Larson M, Haase AT, Douek DC |title=CD4<sup>+</sup> T cell depletion during all stages of HIV disease occurs predominantly in the gastrointestinal tract |journal=J. Exp. Med. |volume=200 |issue=6 |pages=749–59 |year=2004 |month=September |pmid=15365096 |doi=10.1084/jem.20040874 |url=}}</ref> HIV seeks out and destroys CCR5 expressing CD4<sup>+</sup> cells during acute infection. A vigorous immune response eventually controls the infection and initiates the clinically latent phase. However, CD4<sup>+</sup> T cells in mucosal tissues remain depleted throughout the infection, although enough remain to initially ward off life-threatening infections. Continuous HIV replication results in a state of generalized immune activation persisting throughout the chronic phase. <ref name="pmid18161758">{{cite journal |author=Appay V, Sauce D |title=Immune activation and inflammation in HIV-1 infection: causes and consequences |journal=J. Pathol. |volume=214 |issue=2 |pages=231–41 |year=2008 |month=January |pmid=18161758 |doi=10.1002/path.2276 |url=}}</ref> Immune activation, which is reflected by the increased activation state of immune cells and release of proinflammatory [[cytokines]], results from the activity of several HIV gene products and the immune response to ongoing HIV replication. Another cause is the breakdown of the immune surveillance system of the mucosal barrier caused by the depletion of mucosal CD4<sup>+</sup> T cells during the acute phase of disease.<ref name="pmid17115046">{{cite journal |author=Brenchley JM, Price DA, Schacker TW, Asher TE, Silvestri G, Rao S, Kazzaz Z, Bornstein E, Lambotte O, Altmann D, Blazar BR, Rodriguez B, Teixeira-Johnson L, Landay A, Martin JN, Hecht FM, Picker LJ, Lederman MM, Deeks SG, Douek DC |title=Microbial translocation is a cause of systemic immune activation in chronic HIV infection |journal=Nat. Med. |volume=12 |issue=12 |pages=1365–71 |year=2006 |month=December |pmid=17115046 |doi=10.1038/nm1511 |url=}}</ref> This results in the systemic exposure of the immune system to microbial components of the gut’s normal flora, which in a healthy person is kept in check by the mucosal immune system. The activation and proliferation of T cells that results from immune activation provides fresh targets for HIV infection. However, direct killing by HIV alone cannot account for the observed depletion of CD4<sup>+</sup> T cells since only 0.01-0.10% of CD4<sup>+</sup> T cells in the blood are infected. A major cause of CD4<sup>+</sup> T cell loss appears to result from their heightened susceptibility to apoptosis when the immune system remains activated. Although new T cells are continuously produced by the [[thymus]] to replace the ones lost, the regenerative capacity of the thymus is slowly destroyed by direct infection of its [[thymocytes]] by HIV. Eventually, the minimal number of CD4<sup>+</sup> T cells necessary to maintain a sufficient immune response is lost, leading to AIDS ====Cells affected==== The [[virus]], entering through which ever route, acts primarily on the following cells:<ref>Textbook of Pathology by Harsh Mohan, ISBN 81-8061-368-2</ref> #[[Lymphoreticular system]]: ##CD<sub>4</sub>+ [[T-Helper cells]] ##CD<sub>4</sub>+ [[Macrophage]]s ##CD<sub>4</sub>+ [[Monocyte]]s ##[[B-lymphocytes]] #Certain [[endothelial]] cells #[[Central nervous system]]: ##[[Microglia]] of the nervous system ##[[Astrocytes]] ##[[Oligodendrocytes]] ##[[Neurones]] - indirectly by the action of [[cytokines]] and the [[gp-120]] ====The effect==== The [[virus]] has [[cytopathic effect]]s but how it does it is still not quite clear. It can remain inactive in these cells for long periods, though. This effect is hypothesized to be due to the CD<sub>4</sub>-gp120 interaction.<ref>Textbook of Pathology by Harsh Mohan, ISBN 81-8061-368-2</ref> *The most prominent effect of the HIV virus is its T-helper cell suppression and lysis. The cell is simply killed off or deranged to the point of being function-less (they do not respond to foreign [[antigens]]). The infected B-cells can not produce enough antibodies either. Thus the immune system collapses leading to the familiar AIDS complications, like infections and neoplasms (vide supra). *Infection of the cells of the CNS cause acute [[aseptic meningitis]], subacute [[encephalitis]], vacuolar myelopathy and [[peripheral neuropathy]]. Later it leads to even [[AIDS dementia]] complex. *The CD<sub>4</sub>-gp120 interaction (vide supra) is also permissive to other viruses like [[Cytomegalovirus]], [[Hepatitis virus]], [[Herpes simplex]] virus, etc. These viruses lead to further cell damage i.e. cytopathy. ====Molecular basis==== ''For details, see: *[[Structure and genome of HIV]], *[[HIV#Replication_and_transcription|HIV replication cycle]] *[[HIV tropism]]'' ==Diagnosis== The diagnosis of AIDS in a person infected with HIV is based on the presence of certain signs or symptoms. Since [[June 5]], [[1981]], many definitions have been developed for [[epidemiology|epidemiological]] surveillance such as the [[Bangui definition]] and the [[1994 expanded World Health Organization AIDS case definition]]. However, clinical staging of patients was not an intended use for these systems as they are neither sensitive, nor specific. In developing countries, the [[World Health Organization]] staging system for HIV infection and disease, using clinical and laboratory data, is used and in developed countries, the [[Centers for Disease Control and Prevention|Centers for Disease Control]] (CDC) Classification System is used. ===WHO disease staging system=== {{main|WHO Disease Staging System for HIV Infection and Disease}} In 1990, the [[World Health Organization]] (WHO) grouped these infections and conditions together by introducing a staging system for patients infected with HIV-1.<ref name=WHO>{{ cite journal | author=World Health Organization | title=Interim proposal for a WHO staging system for HIV infection and disease | journal=WHO Wkly Epidem. Rec. | year=1990 | pages=221&ndash;228 | volume=65 | issue=29 | pmid=1974812 }}</ref> An update took place in September 2005. Most of these conditions are [[opportunistic infection]]s that are easily treatable in healthy people. * Stage I: HIV infection is [[asymptomatic]] and not categorized as AIDS * Stage II: includes minor [[Mucous membrane|mucocutaneous]] manifestations and recurrent [[upper respiratory tract]] infections * Stage III: includes unexplained [[Chronic (medical)|chronic]] [[diarrhea]]<!--STOP CHANGING THIS: this article is written in American English throughout. --> for longer than a month, severe bacterial infections and [[pulmonary]] tuberculosis * Stage IV: includes [[toxoplasmosis]] of the [[brain]], [[candidiasis]] of the [[esophagus]], [[Vertebrate trachea|trachea]], [[bronchi]] or [[lung]]s and [[Kaposi's sarcoma]]; these diseases are indicators of AIDS. ===CDC classification system=== {{main|CDC Classification System for HIV Infection}} There are two main definitions for AIDS, both produced by the [[Centers for Disease Control and Prevention]] (CDC). The older definition is to referring to AIDS using the diseases that were associated with it, for example, [[lymphadenopathy]], the disease after which the discoverers of HIV originally named the virus.<ref name=MMWR1982a>{{ cite journal | author=Centers for Disease Control (CDC) | title=Persistent, generalized lymphadenopathy among homosexual males. | journal=MMWR Morb Mortal Wkly Rep. | year=1982 | pages=249&ndash;251 | volume=31| issue=19 | pmid=6808340 }}</ref><ref name=Barre>{{cite journal | author=Barré-Sinoussi F, Chermann JC, Rey F, et al | title=Isolation of a T-lymphotropic retrovirus from a patient at risk for acquired immune deficiency syndrome (AIDS) | journal=Science | year=1983 | pages=868–871 | volume=220 | issue=4599 | pmid=6189183 | doi=10.1126/science.6189183 | format= }}</ref> In 1993, the CDC expanded their definition of AIDS to include all HIV positive people with a CD4<SUP>+</SUP> T cell count below 200 per µL of blood or 14% of all [[lymphocyte]]s.<ref name=MMWR>{{ cite web | publisher=[[Centers for Disease Control and Prevention|CDC]] | year=1992 | url=http://www.cdc.gov/mmwr/preview/mmwrhtml/00018871.htm | title=1993 Revised Classification System for HIV Infection and Expanded Surveillance Case Definition for AIDS Among Adolescents and Adults | accessdate = 2006-02-09 }}</ref> The majority of new AIDS cases in [[Developed country|developed countries]] use either this definition or the pre-1993 CDC definition. The AIDS diagnosis still stands even if, after treatment, the CD4<SUP>+</SUP> T cell count rises to above 200 per µL of blood or other AIDS-defining illnesses are cured. ===HIV test=== {{main|HIV test}} Many people are unaware that they are infected with HIV.<ref name=Kumaranayake> {{cite journal | author=Kumaranayake L, Watts C | title= Resource allocation and priority setting of HIV/AIDS interventions: addressing the generalized epidemic in sub-Saharan Africa | journal=J. Int. Dev. | year=2001 | pages=451&ndash;466 | volume=13 | issue=4 | doi=10.1002/jid.798}}</ref> Less than 1% of the sexually active urban population in Africa has been tested, and this proportion is even lower in rural populations. Furthermore, only 0.5% of pregnant women attending urban health facilities are counseled, tested or receive their test results. Again, this proportion is even lower in rural health facilities.<ref name=Kumaranayake> {{cite journal | author=Kumaranayake L, Watts C | title= Resource allocation and priority setting of HIV/AIDS interventions: addressing the generalized epidemic in sub-Saharan Africa | journal=J. Int. Dev. | year=2001 | pages=451&ndash;466 | volume=13 | issue=4 | doi=10.1002/jid.798}}</ref> Therefore, [[donor blood]] and blood products used in medicine and medical research are screened for HIV. HIV tests are usually performed on venous blood. Many laboratories use ''fourth generation'' screening tests which detect anti-HIV antibody (IgG and IgM) and the HIV p24 antigen. The detection of HIV antibody or antigen in a patient previously known to be negative is evidence of HIV infection. Individuals whose first specimen indicates evidence of HIV infection will have a repeat test on a second blood sample to confirm the results. The [[window period]] (the time between initial infection and the development of detectable antibodies against the infection) can vary since it can take 3&ndash;6&nbsp;months to [[seroconversion|seroconvert]] and to test positive. Detection of the virus using polymerase chain reaction ([[PCR]]) during the window period is possible, and evidence suggests that an infection may often be detected earlier than when using a fourth generation EIA screening test. Positive results obtained by PCR are confirmed by antibody tests.<ref name="pmid16706742">{{cite journal |author=Weber B |title=Screening of HIV infection: role of molecular and immunological assays |journal=Expert Rev. Mol. Diagn. |volume=6 |issue=3 |pages=399–411 |year=2006 |pmid=16706742 |doi=10.1586/14737159.6.3.399 |url= }}</ref> Routinely used HIV tests for infection in [[neonates]], born to HIV-positive mothers, have no value because of the presence of maternal antibody to HIV in the child's blood. HIV infection can only be diagnosed by PCR, testing for HIV pro-viral DNA in the children's [[lymphocyte]]s.<ref name="pmid11791341">{{cite journal |author=Tóth FD, Bácsi A, Beck Z, Szabó J |title=Vertical transmission of human immunodeficiency virus |journal=Acta Microbiol Immunol Hung |volume=48 |issue=3-4 |pages=413–27 |year=2001 |pmid=11791341 |doi=10.1556/AMicr.48.2001.3-4.10 }}</ref> ==Prevention== {| class="prettytable" style="float:right; font-size:85%; margin-left:15px;" |- bgcolor="#efefef" |+ Estimated per act risk for acquisition<br/>of HIV by exposure route<ref name=MMWR3>{{ cite journal | author=Smith DK, Grohskopf LA, Black RJ, et al | title=Antiretroviral Postexposure Prophylaxis After Sexual, Injection-Drug Use, or Other Nonoccupational Exposure to HIV in the United States | journal=MMWR | year=2005 | pages=1&ndash;20 | volume=54 | issue=RR02 | url=http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5402a1.htm#tab1 }}</ref> |- bgcolor="#efefef" ! style="width: 100px" abbr="Route" | Exposure Route ! style="width: 130px" abbr="Infections" | Estimated infections<br/>per 10,000 exposures<br/>to an infected source |- ! style="text-align:left"| Blood Transfusion | 9,000<ref name=Donegan>{{ cite journal | author=Donegan E, Stuart M, Niland JC, et al | title=Infection with human immunodeficiency virus type 1 (HIV-1) among recipients of antibody-positive blood donations | journal=Ann. Intern. Med. | year=1990 | pages=733&ndash;739 | volume=113 | issue=10 | pmid=2240875 }}</ref> |- ! style="text-align:left"| Childbirth | 2,500<ref name=Coovadia>{{ cite journal | author=Coovadia H | title=Antiretroviral agents&mdash;how best to protect infants from HIV and save their mothers from AIDS | journal=N. Engl. J. Med. | year=2004 | pages=289&ndash;292 | volume=351 | issue=3 | pmid=15247337 }}</ref> |- ! style="text-align:left"| Needle-sharing injection drug use | 67<ref name=Kaplan>{{ cite journal | author=Kaplan EH, Heimer R | title=HIV incidence among New Haven needle exchange participants: updated estimates from syringe tracking and testing data | journal=J. Acquir. Immune Defic. Syndr. Hum. Retrovirol. | year=1995 | pages=175&ndash;176 | volume=10 | issue=2 | pmid=7552482 }}</ref> |- ! style="text-align:left"| Percutaneous needle stick | 30<ref name=Bell>{{ cite journal | author=Bell DM | title=Occupational risk of human immunodeficiency virus infection in healthcare workers: an overview. | journal=Am. J. Med. | year=1997 | pages=9&ndash;15 | volume=102 | issue=5B | pmid=9845490 }}</ref> |- ! style="text-align:left"| Receptive anal intercourse<sup>*</sup> | 50<ref name=ESG>{{ cite journal | author=European Study Group on Heterosexual Transmission of HIV | title=Comparison of female to male and male to female transmission of HIV in 563 stable couples | journal=BMJ. | year=1992 | pages=809&ndash;813 | volume=304 | issue=6830 | pmid=1392708 }}</ref><ref name=Varghese>{{ cite journal | author=Varghese B, Maher JE, Peterman TA, Branson BM,Steketee RW | title=Reducing the risk of sexual HIV transmission: quantifying the per-act risk for HIV on the basis of choice of partner, sex act, and condom use | journal=Sex. Transm. Dis. | year=2002 | pages=38&ndash;43 | volume=29 | issue=1 | pmid=11773877 }}</ref> |- ! style="text-align:left"| Insertive anal intercourse<sup>*</sup> | 6.5<ref name=ESG /><ref name=Varghese /> |- ! style="text-align:left"| Receptive penile-vaginal intercourse<sup>*</sup> | 10<ref name=ESG /><ref name=Varghese /><ref name=Leynaert>{{ cite journal | author=Leynaert B, Downs AM, de Vincenzi I | title=Heterosexual transmission of human immunodeficiency virus: variability of infectivity throughout the course of infection. European Study Group on Heterosexual Transmission of HIV | journal=Am. J. Epidemiol. | year=1998 | pages=88&ndash;96 | volume=148 | issue=1 | pmid=9663408 }}</ref> |- ! style="text-align:left"| Insertive penile-vaginal intercourse<sup>*</sup> | 5<ref name=ESG /><ref name=Varghese /> |- ! style="text-align:left"| Receptive oral intercourse<sup>*§</sup> | 1<ref name=Varghese /> |- ! style="text-align:left"| Insertive oral intercourse<sup>*</sup> | 0.5<ref name=Varghese /><sup>§</sup> |- bgcolor="#efefef" ! colspan=5 style="border-right:0px;";| <sup>*</sup> assuming no condom use </br> <sup>§</sup> source refers to oral intercourse<br/>performed on a man |} The three main transmission routes of HIV are [[sexual contact]], exposure to infected body fluids or tissues, and from mother to [[fetus]] or child during [[perinatal]] period. It is possible to find HIV in the [[saliva]], [[tears]], and [[urine]] of infected individuals, but there are no recorded cases of infection by these secretions, and the risk of infection is negligible.<ref>{{ cite web | url=http://www.avert.org/aids.htm | publisher = avert.org | title=Facts about AIDS & HIV | accessdate = 2007-11-30 }}</ref> ===Sexual contact=== The majority of HIV infections are acquired through [[Bareback (sex)|unprotected sex]]ual relations between partners, one of whom has HIV. The primary mode of HIV infection worldwide is through sexual contact between members of the opposite sex.<ref>{{ cite journal | author=Johnson AM, Laga M | title=Heterosexual transmission of HIV | journal=AIDS | year=1988 | pages=S49-S56| volume=2 | issue=suppl. 1 | pmid=3130121 }}</ref><ref>{{ cite journal | author=N'Galy B, Ryder RW | title=Epidemiology of HIV infection in Africa | journal=Journal of Acquired Immune Deficiency Syndromes | year=1988 | pages=551-558 | volume=1 | issue=6 | pmid=3225742 }}</ref><ref>{{ cite journal | author=Deschamps MM, Pape JW, Hafner A, Johnson WD Jr. | title=Heterosexual transmission of HIV in Haiti | journal=Annals of Internal Medicine | year=1996 | pages=324&ndash;330 | volume=125 | issue=4 | pmid=8678397 }}</ref> During a sexual act, only male or female [[condom]]s can reduce the chances of infection with HIV and other STDs and the chances of becoming [[pregnant]]. The best evidence to date indicates that typical condom use reduces the risk of [[heterosexual]] HIV transmission by approximately 80% over the long-term, though the benefit is likely to be higher if condoms are used correctly on every occasion.<ref name=Cayley>{{ cite journal | author=Cayley WE Jr. | title=Effectiveness of condoms in reducing heterosexual transmission of HIV | journal=Am. Fam. Physician | year=2004 | pages=1268&ndash;1269 | volume=70 | issue=7 | pmid=15508535 }}</ref> The male [[latex]] condom, if used correctly without oil-based lubricants, is the single most effective available technology to reduce the sexual transmission of HIV and other sexually transmitted infections. Manufacturers recommend that oil-based lubricants such as [[petroleum jelly]], butter, and [[lard]] not be used with latex condoms, because they dissolve the [[latex]], making the condoms [[Porosity|porous]]. If necessary, manufacturers recommend using [[water]]-based lubricants. Oil-based lubricants can however be used with [[polyurethane]] condoms.<ref name=Durex>{{ cite web | publisher=[[Durex]] | year= | url=http://www.durex.com/cm/assets/SexEdDownloads/Module_5_condoms.doc | title=Module 5/Guidelines for Educators | format= [[Microsoft Word]] | accessdate = 2006-04-17 }}</ref> The [[female condom]] is an alternative to the male condom and is made from [[polyurethane]], which allows it to be used in the presence of oil-based lubricants. They are larger than male condoms and have a stiffened ring-shaped opening, and are designed to be inserted into the vagina. The female condom contains an inner ring, which keeps the condom in place inside the vagina &ndash; inserting the female condom requires squeezing this ring. However, at present availability of female condoms is very low and the price remains prohibitive for many women. Preliminary studies suggest that, where female condoms are available, overall protected sexual acts increase relative to unprotected sexual acts, making them an important HIV prevention strategy.<ref name=PATH>{{ cite journal | author=PATH | title=The female condom: significant potential for STI and pregnancy prevention | journal=Outlook | year=2006 | volume=22 | issue=2 }}</ref> Studies on couples where one partner is infected show that with consistent condom use, HIV infection rates for the uninfected partner are below 1% per year.<ref name=WHOCondoms>{{ cite web | publisher=[[World Health Organization|WHO]]| year= August 2003 | url=http://www.wpro.who.int/media_centre/fact_sheets/fs_200308_Condoms.htm | title=Condom Facts and Figures | accessdate = 2006-01-17 }}</ref> Prevention strategies are well-known in developed countries, however, recent epidemiological and behavioral studies in Europe and North America have suggested that a substantial minority of young people continue to engage in high-risk practices and that despite HIV/AIDS knowledge, young people underestimate their own risk of becoming infected with HIV.<ref name=Dias>{{ cite journal | author=Dias SF, Matos MG, Goncalves, A. C. | title=Preventing HIV transmission in adolescents: an analysis of the Portuguese data from the Health Behaviour School-aged Children study and focus groups | journal=Eur. J. Public Health | year=2005 | pages=300&ndash;304 | volume=15 | issue=3 | pmid=15941747 }}</ref> [[Randomized controlled trial]]s have shown that male [[circumcision]] lowers the risk of HIV infection among heterosexual men by up to 60%.<ref>{{cite journal |author=Weiss HA |title=Male circumcision as a preventive measure against HIV and other sexually transmitted diseases |journal=Curr. Opin. Infect. Dis. |volume=20 |issue=1 |pages=66–72 |year=2007 |month=February |pmid=17197884 |doi=10.1097/QCO.0b013e328011ab73}}</ref> It is expected that this procedure will be actively promoted in many of the countries affected by HIV, although doing so will involve confronting a number of practical, cultural and attitudinal issues. Some experts fear that a lower perception of vulnerability among circumcised men may result in more sexual risk-taking behavior, thus negating its preventive effects.<ref>{{cite journal |author=Eaton LA, Kalichman S |title=Risk compensation in HIV prevention: implications for vaccines, microbicides, and other biomedical HIV prevention technologies |journal=Curr HIV/AIDS Rep |volume=4 |issue=4 |pages=165–72 |year=2007 |month=December |pmid=18366947 |doi=10.1007/s11904-007-0024-7}}</ref> ===Exposure to infected body fluids=== Health care workers can reduce exposure to HIV by employing precautions to reduce the risk of exposure to contaminated blood. These precautions include barriers such as gloves, masks, protective eyeware or shields, and gowns or aprons which prevent exposure of the skin or mucous membranes to blood borne pathogens. Frequent and thorough washing of the skin immediately after being contaminated with blood or other bodily fluids can reduce the chance of infection. Finally, sharp objects like needles, scalpels and glass, are carefully disposed of to prevent needlestick injuries with contaminated items.<ref>{{cite web |url=http://www.cdc.gov/MMWR/PREVIEW/MMWRHTML/00023587.htm |title=Recommendations for Prevention of HIV Transmission in Health-Care Settings |format= |work= |accessdate=2008-04-28 }}</ref> Since intravenous drug use is an important factor in HIV transmission in developed countries, [[harm reduction]] strategies such as [[needle-exchange programme]]s are used in attempts to reduce the infections caused by drug abuse.<ref>{{cite journal |author=Kerr T, Kimber J, Debeck K, Wood E |title=The role of safer injection facilities in the response to HIV/AIDS among injection drug users |journal=Curr HIV/AIDS Rep |volume=4 |issue=4 |pages=158–64 |year=2007 |month=December |pmid=18366946 |doi=10.1007/s11904-007-0023-8}}</ref><ref>{{cite journal |author=Wodak A, Cooney A |title=Do needle syringe programs reduce HIV infection among injecting drug users: a comprehensive review of the international evidence |journal=Subst Use Misuse |volume=41 |issue=6-7 |pages=777–813 |year=2006 |pmid=16809167 |doi=10.1080/10826080600669579}}</ref> ===Mother-to-child transmission (MTCT)=== Current recommendations state that when replacement feeding is acceptable, feasible, affordable, sustainable and safe, HIV-infected mothers should avoid breast-feeding their infant. However, if this is not the case, exclusive breast-feeding is recommended during the first months of life and discontinued as soon as possible.<ref>{{cite web |url=http://www.who.int/hiv/mediacentre/Infantfeedingconsensusstatement.pf.pdf |format=PDF |date=2006 |accessdate=2008-03-12 |title= Consensus statement |author= WHO HIV and Infant Feeding Technical Consultation }}</ref> ==Treatment== <!-- Note that HIV and AIDS are two different pages, so the HIV Treatment link is going to similar material on a different page; it is not simply redirecting back here. --> :''See also [[HIV#Treatment|HIV Treatment]] and [[Antiretroviral drug]]. [[Image:Abacavir (Ziagen) 300mg.jpg|right|thumb|100px|''[[Abacavir]]'' – a nucleoside analog reverse transcriptase inhibitors (NARTIs or NRTIs)]] [[Image:Abacavir structure.svg|right|thumb|100px|The chemical structure of Abacavir]] There is currently no [[HIV vaccine|vaccine]] or cure for [[HIV]] or AIDS. The only known methods of prevention are based on avoiding exposure to the virus or, failing that, an antiretroviral treatment directly after a highly significant exposure, called [[post-exposure prophylaxis]] (PEP).<ref>{{cite journal |author=Hamlyn E, Easterbrook P |title=Occupational exposure to HIV and the use of post-exposure prophylaxis |journal=Occup Med (Lond) |volume=57 |issue=5 |pages=329–36 |year=2007 |month=August |pmid=17656498 |doi=10.1093/occmed/kqm046}}</ref> PEP has a very demanding four week schedule of dosage. It also has very unpleasant side effects including [[diarrhea]], [[malaise]], [[nausea]] and [[Fatigue (physical)|fatigue]].<ref name=PEPpocketguide>{{ cite web | publisher=[[Department of Health and Human Services]] | date=February 2006 | url=http://hab.hrsa.gov/tools/HIVpocketguide/PktGPEP.htm | title=A Pocket Guide to Adult HIV/AIDS Treatment February 2006 edition | accessdate = 2006-09-01 }}</ref> ===Antiviral therapy=== Current treatment for HIV infection consists of [[highly active antiretroviral therapy]], or HAART.<ref name=DhhsHivTreatment>{{ cite web | publisher=[[Department of Health and Human Services]] | date=February 2006 | url=http://hab.hrsa.gov/tools/HIVpocketguide/PktGARTtables.htm | title=A Pocket Guide to Adult HIV/AIDS Treatment February 2006 edition | accessdate = 2006-09-01 }}</ref> This has been highly beneficial to many HIV-infected individuals since its introduction in 1996 when the protease inhibitor-based HAART initially became available.<ref name=Palella/> Current optimal HAART options consist of combinations (or "cocktails") consisting of at least three drugs belonging to at least two types, or "classes," of [[antiretroviral]] agents. Typical regimens consist of two [[nucleoside analogue reverse transcriptase inhibitor]]s (NARTIs or NRTIs) plus either a [[protease inhibitor (pharmacology)|protease inhibitor]] or a [[non-nucleoside reverse transcriptase inhibitor]] (NNRTI). Because HIV disease progression in children is more rapid than in adults, and laboratory parameters are less predictive of risk for disease progression, particularly for young infants, treatment recommendations are more aggressive for children than for adults.<ref name=2005dhhsHivChildren>{{ cite web | publisher=[[Department of Health and Human Services]] Working Group on Antiretroviral Therapy and Medical Management of HIV-Infected Children | date=2005-11-03 | url=http://www.aidsinfo.nih.gov/ContentFiles/PediatricGuidelines_PDA.pdf | title=Guidelines for the Use of Antiretroviral Agents in Pediatric HIV Infection | format= PDF | accessdate = 2006-01-17 }}</ref> In developed countries where HAART is available, doctors assess the [[viral load]], rapidity in CD4 decline, and patient readiness while deciding when to recommend initiating treatment.<ref name=2005DhhsHivTreatment>{{ cite web | publisher=[[Department of Health and Human Services]] Panel on Clinical Practices for Treatment of HIV Infection | date=2005-10-06 | url=http://aidsinfo.nih.gov/ContentFiles/AdultandAdolescentGL.pdf | title=Guidelines for the Use of Antiretroviral Agents in HIV-1-Infected Adults and Adolescents | format= PDF | accessdate = 2006-01-17 }}</ref> HAART allows the stabilization of the patient’s symptoms and viremia, but it neither cures the patient of HIV, nor alleviates the symptoms, and high levels of HIV-1, often HAART resistant, return once treatment is stopped.<ref name=martinez>{{ cite journal | author=Martinez-Picado J, DePasquale MP, Kartsonis N, et al| title=Antiretroviral resistance during successful therapy of human immunodeficiency virus type 1 infection | journal=Proc. Natl. Acad. Sci. U. S. A. | year=2000 | pages=10948&ndash;10953 | volume=97 | issue=20 | pmid=11005867 }}</ref><ref name=Dybul>{{ cite journal | author=Dybul M, Fauci AS, Bartlett JG, Kaplan JE, Pau AK; Panel on Clinical Practices for Treatment of HIV. | title=Guidelines for using antiretroviral agents among HIV-infected adults and adolescents | journal=Ann. Intern. Med. | year=2002 | pages=381&ndash;433 | volume=137 | issue=5 Pt 2 | pmid=12617573 }}</ref> Moreover, it would take more than the lifetime of an individual to be cleared of HIV infection using HAART.<ref name=blankson>{{ cite journal | author=Blankson JN, Persaud D, Siliciano RF | title=The challenge of viral reservoirs in HIV-1 infection | journal=Annu. Rev. Med. | year=2002 | pages=557&ndash;593 | volume=53 | issue= | pmid=11818490 }}</ref> Despite this, many HIV-infected individuals have experienced remarkable improvements in their general health and quality of life, which has led to the plummeting of HIV-associated morbidity and mortality.<ref name=Pallelal>{{ cite journal | author=Palella FJ, Delaney KM, Moorman AC, Loveless MO, Fuhrer J, Satten GA, Aschman DJ, Holmberg SD | title=Declining morbidity and mortality among patients with advanced human immunodeficiency virus infection | journal=N. Engl. J. Med. | year=1998 | pages=853&ndash;860 | volume=338 | issue=13 | pmid=9516219 }}</ref><ref name=Wood>{{ cite journal | author=Wood E, Hogg RS, Yip B, Harrigan PR, O'Shaughnessy MV, Montaner JS | title=Is there a baseline CD4 cell count that precludes a survival response to modern antiretroviral therapy? | journal=AIDS | year=2003 | pages=711&ndash;720 | volume=17 | issue=5 | pmid=12646794 }}</ref><ref name=Chene>{{ cite journal | author=Chene G, Sterne JA, May M, Costagliola D, Ledergerber B, Phillips AN, Dabis F, Lundgren J, D'Arminio Monforte A, de Wolf F, Hogg R, Reiss P, Justice A, Leport C, Staszewski S, Gill J, Fatkenheuer G, Egger ME and the Antiretroviral Therapy Cohort Collaboration | title=Prognostic importance of initial response in HIV-1 infected patients starting potent antiretroviral therapy: analysis of prospective studies | journal=Lancet | year=2003 | pages=679&ndash;686 | volume=362 | issue=9385 | pmid=12957089 | doi=10.1016/S0140-6736(03)14229-8 }}</ref> In the absence of HAART, progression from HIV infection to AIDS occurs at a [[median]] of between nine to ten years and the median survival time after developing AIDS is only 9.2&nbsp;months.<ref name=Morgan2 /> HAART is thought to increase survival time by between 4 and 12&nbsp;years.<ref name=JTKing>{{ cite journal | author=King JT, Justice AC, Roberts MS, Chang CH, Fusco JS and the CHORUS Program Team | title=Long-Term HIV/AIDS Survival Estimation in the Highly Active Antiretroviral Therapy Era | journal=Medical Decision Making | year=2003 | pages=9&ndash;20 | volume=23 | issue=1 | pmid=12583451 }}</ref><ref name=Tassie>{{ cite journal | author=Tassie JM, Grabar S, Lancar R, Deloumeaux J, Bentata M, Costagliola D and the Clinical Epidemiology Group from the French Hospital Database on HIV | title=Time to AIDS from 1992 to 1999 in HIV-1-infected subjects with known date of infection | journal=Journal of acquired immune deficiency syndromes | year=2002 | pages=81&ndash;7 | volume=30 | issue=1 | pmid=12048367 }}</ref> For some patients, which can be more than fifty percent of patients, HAART achieves far less than optimal results, due to medication intolerance/side effects, prior ineffective antiretroviral therapy and infection with a drug-resistant strain of HIV. Non-adherence and non-persistence with therapy are the major reasons why some people do not benefit from HAART.<ref name=becker>{{ cite journal | author=Becker SL, Dezii CM, Burtcel B, Kawabata H, Hodder S. | title=Young HIV-infected adults are at greater risk for medication nonadherence | journal=MedGenMed. | year=2002 | pages=21 | volume=4| issue=3 | pmid=12466764 }}</ref> The reasons for non-adherence and non-persistence are varied. Major psychosocial issues include poor access to medical care, inadequate social supports, psychiatric disease and drug abuse. HAART regimens can also be complex and thus hard to follow, with large numbers of pills taken frequently.<ref name=Nieuwkerk>{{ cite journal | author=Nieuwkerk P, Sprangers M, Burger D, Hoetelmans RM, Hugen PW, Danner SA, van Der Ende ME, Schneider MM, Schrey G, Meenhorst PL, Sprenger HG, Kauffmann RH, Jambroes M, Chesney MA, de Wolf F, Lange JM and the ATHENA Project | title=Limited Patient Adherence to Highly Active Antiretroviral Therapy for HIV-1 Infection in an Observational Cohort Study | journal=Arch. Intern. Med. | year=2001 | pages=1962&ndash;1968 | volume=161 | issue=16 | pmid=11525698 }}</ref><ref name=Kleeberger>{{ cite journal | author=Kleeberger C, Phair J, Strathdee S, Detels R, Kingsley L, Jacobson LP | title=Determinants of Heterogeneous Adherence to HIV-Antiretroviral Therapies in the Multicenter AIDS Cohort Study| journal=J. Acquir. Immune Defic. Syndr. | year=2001 | pages=82&ndash;92 | volume=26 | issue=1 | pmid=11176272 }}</ref><ref name=heath>{{ cite journal | author=Heath KV, Singer J, O'Shaughnessy MV, Montaner JS, Hogg RS | title=Intentional Nonadherence Due to Adverse Symptoms Associated With Antiretroviral Therapy | journal=J. Acquir. Immune Defic. Syndr. | year=2002 | pages=211&ndash;217 | volume=31 | issue=2 | pmid=12394800 }}</ref> Side effects can also deter people from persisting with HAART, these include [[lipodystrophy]], [[dyslipidaemia]], [[diarrhoea]], [[insulin resistance]], an increase in [[cardiovascular]] risks and [[birth defect]]s.<ref>{{cite journal |author=Burgoyne RW, Tan DH |title=Prolongation and quality of life for HIV-infected adults treated with highly active antiretroviral therapy (HAART): a balancing act |journal=J. Antimicrob. Chemother. |volume=61 |issue=3 |pages=469–73 |year=2008 |month=March |pmid=18174196 |doi=10.1093/jac/dkm499 |url=http://jac.oxfordjournals.org/cgi/pmidlookup?view=long&pmid=18174196}}</ref> Anti-retroviral drugs are expensive, and the majority of the world's infected individuals do not have access to medications and treatments for HIV and AIDS. ===Abzyme=== In a June 2006 issue of the journal Autoimmunity Reviews,<ref name="physorg">{{cite web |url=http://www.physorg.com/news135360794.html |title=UT pathologists believe they have pinpointed Achilles heel of HIV |format= |work=physorg.com |accessdate=2008-07-16}}</ref> researchers of the University Of Texas Medical School at [[Houston]] announced discovery of an [[abzyme]] that can destroy the protein [[gp120]] CD4 binding site. This protein is common to all HIV variants as it is the attachment point for [[B cell|B lymphocytes]] and subsequent compromising of the immune system. Testing in human trials is pending to determine its effectiveness as a [[vaccine]]. ===Future research=== It has been postulated that only a vaccine can halt the pandemic because a vaccine would possibly cost less, thus being affordable for developing countries, and would not require daily treatments. However, even after almost 30&nbsp;years of research, HIV-1 remains a difficult target for a vaccine.<ref>{{cite journal |author=Karlsson Hedestam GB, Fouchier RA, Phogat S, Burton DR, Sodroski J, Wyatt RT |title=The challenges of eliciting neutralizing antibodies to HIV-1 and to influenza virus |journal=Nat. Rev. Microbiol. |volume=6 |issue=2 |pages=143–55 |year=2008 |month=February |pmid=18197170 |doi=10.1038/nrmicro1819}}</ref> Research to improve current treatments includes decreasing side effects of current drugs, further simplifying drug regimens to improve adherence, and determining the best sequence of regimens to manage drug resistance. A number of studies have shown that measures to prevent opportunistic infections can be beneficial when treating patients with HIV infection or AIDS. [[Vaccination]] against [[hepatitis]] A and B is advised for patients who are not infected with these viruses and are at risk of becoming infected.<ref name=Laurence>{{ cite journal | author=Laurence J | title=Hepatitis A and B virus immunization in HIV-infected persons | journal=AIDS Reader | year=2006 | pages=15&ndash;17 | volume=16 | issue=1 | pmid=16433468 }}</ref> Patients with substantial immunosuppression are also advised to receive prophylactic therapy for [[Pneumocystis jiroveci pneumonia]] (PCP), and many patients may benefit from prophylactic therapy for [[toxoplasmosis]] and [[Cryptococcus]] [[meningitis]] as well.<ref name=PEPpocketguide>{{ cite web | publisher=[[Department of Health and Human Services]] | date = 2007-02-02 | url=http://www.guideline.gov/summary/summary.aspx?ss=14&doc_id=6223&string=infected+AND+patients | title=Treating opportunistic infections among HIV-infected adults and adolescents. Recommendations from CDC, the National Institutes of Health, and the HIV Medicine Association/Infectious Diseases Society of America. | accessdate = 2007-02-05 }}</ref> ===Alternative medicine=== Various forms of [[alternative medicine]] have been used to treat symptoms or alter the course of the disease.<ref name="CAM effectiveness">{{cite journal|author=Power R, Gore-Felton C, Vosvick M, Israelski DM, Spiegel D |title=HIV: effectiveness of complementary and alternative medicine |journal=Prim. Care |volume=29 |issue=2 |pages=361–78 |year=2002 |month=June |pmid=12391716 |doi= |url= |accessdate=2008-04-28 }}</ref> [[Acupuncture]] has been used to alleviate some symptoms, such peripheral neuropathy, but cannot cure the HIV infection.<ref>{{cite journal |author=Nicholas PK, Kemppainen JK, Canaval GE, ''et al'' |title=Symptom management and self-care for peripheral neuropathy in HIV/AIDS |journal=AIDS Care |volume=19 |issue=2 |pages=179–89 |year=2007 |month=February |pmid=17364396 |doi=10.1080/09540120600971083 |url=http://www.informaworld.com/openurl?genre=article&doi=10.1080/09540120600971083&magic=pubmed||1B69BA326FFE69C3F0A8F227DF8201D0 |accessdate=2008-04-28 }}</ref> Several randomized clinical trials testing the effect of herbal medicines have shown that there is no evidence that these herbs have any effect on the progression of the disease, but may instead produce serious side-effects.<ref>{{cite journal |author=Liu JP, Manheimer E, Yang M |title=Herbal medicines for treating HIV infection and AIDS |journal=Cochrane Database Syst Rev |volume= |issue=3 |pages=CD003937 |year=2005 |pmid=16034917 |doi=10.1002/14651858.CD003937.pub2 |url= |accessdate=2008-04-28 }}</ref> Some data suggest that [[multivitamin]] and mineral supplements might reduce HIV disease progression in adults, although there is no conclusive evidence on if they reduce mortality among people with good nutritional status.<ref name=Irlam/> [[Vitamin A]] supplementation in children probably has some benefit.<ref name=Irlam>{{cite journal |author=Irlam JH, Visser ME, Rollins N, Siegfried N |title=Micronutrient supplementation in children and adults with HIV infection |journal=Cochrane Database Syst Rev |volume= |issue=4 |pages=CD003650 |year=2005 |pmid=16235333 |doi=10.1002/14651858.CD003650.pub2}}</ref> Daily doses of [[selenium]] can suppress HIV viral burden with an associated improvement of the CD4 count. Selenium can be used as an adjunct therapy to standard antiviral treatments, but cannot itself reduce mortality and morbidity.<ref>{{cite journal |author=Hurwitz BE, Klaus JR, Llabre MM, ''et al'' |title=Suppression of human immunodeficiency virus type 1 viral load with selenium supplementation: a randomized controlled trial |journal=Arch. Intern. Med. |volume=167 |issue=2 |pages=148–54 |year=2007 |month=January |pmid=17242315 |doi=10.1001/archinte.167.2.148 |url= |accessdate=2008-04-28 }}</ref> Current studies indicate that that alternative medicine therapies have little effect on the mortality or morbidity of the disease, but may improve the quality of life of individuals afflicted with AIDS. The psychological benefits of these therapies are the most important use.<ref name="CAM effectiveness"/> ==Epidemiology== {{main|AIDS pandemic}} [[Image:HIV Epidem.png|290px|thumb|right|Estimated prevalence of HIV among young adults (15-49) per country at the end of 2005]] The AIDS pandemic can also be seen as several epidemics of separate subtypes; the major factors in its spread are sexual transmission and vertical transmission from mother to child at birth and through breast milk.<ref name=Kallings/> Despite recent, improved access to antiretroviral treatment and care in many regions of the world, the AIDS pandemic claimed an estimated 2.1&nbsp;million (range 1.9–2.4&nbsp;million) lives in 2007 of which an estimated 330,000 were children under 15&nbsp;years.<ref name=UNAIDS2007>{{ cite web | author =[[Joint United Nations Programme on HIV/AIDS|UNAIDS]], [[World Health Organization|WHO]] | date = December 2007 | title = 2007 AIDS epidemic update | url= http://data.unaids.org/pub/EPISlides/2007/2007_epiupdate_en.pdf | accessdate = 2008-03-12 | format= PDF }}</ref> Globally, an estimated 33.2&nbsp;million people lived with HIV in 2007, including 2.5&nbsp;million children. An estimated 2.5 million (range 1.8–4.1&nbsp;million) people were newly infected in 2007, including 420,000 children.<ref name=UNAIDS2007/> [[AIDS pandemic#Sub-Saharan Africa|Sub-Saharan Africa]] remains by far the worst affected region. In 2007 it contained an estimated 68% of all people living with AIDS and 76% of all AIDS deaths, with 1.7&nbsp;million new infections bringing the number of people living with HIV to 22.5&nbsp;million, and with 11.4&nbsp;million AIDS orphans living in the region. Unlike other regions, most people living with HIV in sub-Saharan Africa in 2007 (61%) were women. Adult [[prevalence]] in 2007 was an estimated 5.0%, and AIDS continued to be the single largest cause of mortality in this region.<ref name=UNAIDS2007/> [[South Africa]] has the largest population of HIV patients in the world, followed by [[Nigeria]] and [[India]].<ref> {{cite news | date = 2007-11-20 | title= U.N. agency to say it overstated extent of H.I.V. cases by millions | url= http://query.nytimes.com/gst/fullpage.html?res=9C01EEDF103BF933A15752C1A9619C8B63 | work= New York Times | accessdate=2008-03-18 | author= McNeil DG Jr }}</ref> [[AIDS pandemic#South and South-East Asia|South & South East Asia]] are second worst affected; in 2007 this region contained an estimated 18% of all people living with AIDS, and an estimated 300,000 deaths from AIDS.<ref name=UNAIDS2007/> India has an estimated 2.5&nbsp;million infections and an estimated adult prevalence of 0.36%.<ref name=UNAIDS2007/> [[Life expectancy]] has fallen dramatically in the worst-affected countries; for example, in 2006 it was estimated that it had dropped from 65 to 35 years in [[Botswana]].<ref name=Kallings>{{cite journal |journal= J Intern Med |date=2008 |volume=263 |issue=3 |pages=218–43 |title= The first postmodern pandemic: 25 years of HIV/AIDS |author= Kallings LO |doi=10.1111/j.1365-2796.2007.01910.x |pmid=18205765 |url=http://www.blackwell-synergy.com/doi/full/10.1111/j.1365-2796.2007.01910.x}}</ref> ==Prognosis== Without treatment, the net median survival time after infection with HIV is estimated to be 9 to 11 years, depending on the HIV subtype,<ref name=UNAIDS2007/> and the median survival rate after diagnosis of AIDS in resource-limited settings where treatment is not available ranges between 6 and 19 months, depending on the study.<ref>{{cite paper |title= Progression and mortality of untreated HIV-positive individuals living in resource-limited settings: update of literature review and evidence synthesis |author= Zwahlen M, Egger M |url=http://data.unaids.org/pub/Periodical/2006/zwahlen_unaids_hq_05_422204_2007_en.pdf |format=PDF |date=2006 |accessdate=2008-03-19 |version= UNAIDS Obligation HQ/05/422204}}</ref> In areas where it is widely available, the development of [[HAART]] as effective therapy for HIV infection and AIDS reduced the death rate from this disease by 80%, and raised the life expectancy for a newly-diagnosed HIV-infected person to about 20 years.<ref>{{cite journal |journal= Int J Dermatol |date=2007 |volume=46 |issue=12 |pages=1219–28 |title= Current status of HIV infection: a review for non-HIV-treating physicians |author= Knoll B, Lassmann B, Temesgen Z |pmid=18173512 |doi=10.1111/j.1365-4632.2007.03520.x}}</ref> As new treatments continue to be developed and because HIV continues to [[Evolution|evolve]] resistance to treatments, estimates of survival time are likely to continue to change. Without antiretroviral therapy, death normally occurs within a year.<ref name=Morgan2 /> Most patients die from opportunistic infections or [[malignancies]] associated with the progressive failure of the immune system.<ref name=Lawn>{{ cite journal | author=Lawn SD | title=AIDS in Africa: the impact of coinfections on the pathogenesis of HIV-1 infection | journal=J. Infect. Dis. | year=2004 | pages=1&ndash;12 | volume=48 | issue=1 | pmid=14667787 }}</ref> The rate of clinical disease progression varies widely between individuals and has been shown to be affected by many factors such as host susceptibility and immune function<ref name=Clerici /><ref name=Morgan /><ref name=Tang /> health care and co-infections,<ref name=Morgan2 /><ref name=Lawn /> as well as which particular strain of the virus is involved.<ref name=Campbell /><ref name=Campbell2>{{ cite journal | author=Campbell GR, Watkins JD, Esquieu D, Pasquier E, Loret EP, Spector SA | title=The C terminus of HIV-1 Tat modulates the extent of CD178-mediated apoptosis of T cells | journal=J. Biol. Chem. | year=2005 | pages=38376&ndash;39382 | volume=280 | issue=46 | pmid=16155003 }}</ref><ref name=Senkaali>{{ cite journal | author=Senkaali D, Muwonge R, Morgan D, Yirrell D, Whitworth J, Kaleebu P | title=The relationship between HIV type 1 disease progression and V3 serotype in a rural Ugandan cohort | journal=AIDS Res. Hum. Retroviruses. | year=2005 | pages=932&ndash;937 | volume=20 | issue=9 | pmid=15585080 }}</ref> ==History== {{main|AIDS origin}} AIDS was first reported [[June 5]], [[1981]], when the U.S. [[Centers for Disease Control and Prevention]] recorded a cluster of [[Pneumocystis pneumonia (PCP)|''Pneumocystis carinii'' pneumonia]] (now still classified as PCP but known to be caused by [[Pneumocystis pneumonia (PCP)|''Pneumocystis jirovecii'']]) in five homosexual men in [[Los Angeles, California|Los Angeles]].<ref name=MMWR2>{{cite journal |author=Gottlieb MS |title=Pneumocystis pneumonia--Los Angeles. 1981 |journal=Am J Public Health |volume=96 |issue=6 |pages=980–1; discussion 982–3 |year=2006 |pmid=16714472 |url=http://www.cdc.gov/mmwr/preview/mmwrhtml/june_5.htm |doi= }}</ref> In the beginning, the [[Centers for Disease Control and Prevention]] (CDC) did not have an official name for the disease, often referring to it by way of the diseases that were associated with it, for example, [[lymphadenopathy]], the disease after which the discoverers of HIV originally named the virus.<ref name=MMWR1982a/><ref name=Barre/> They also used ''Kaposi's Sarcoma and Opportunistic Infections'', the name by which a task force had been set up in 1981.<ref name=MMWR1982b>{{ cite journal | author=Centers for Disease Control (CDC) | title=Opportunistic infections and Kaposi's sarcoma among Haitians in the United States | journal=MMWR Morb Mortal Wkly Rep. | year=1982 | pages=353&ndash;354; 360&ndash;361 | volume=31 | issue=26 | pmid=6811853 }}</ref> In the general press, the term ''GRID'', which stood for [[Gay-related immune deficiency]], had been coined.<ref name=Altman>{{ cite news | author=Altman LK | title=New homosexual disorder worries officials | work=The New York Times | date=1982-05-11 }}</ref> The CDC, in search of a name, and looking at the infected communities coined “the 4H disease,” as it seemed to single out [[Haiti]]ans, [[homosexual]]s, [[hemophiliacs]], and [[heroin]] users.<ref name=SciRep470b>{{ cite web | publisher=[[American Association for the Advancement of Science]] | date= 2006-07-28 | url=http://www.scienceonline.org/cgi/reprint/313/5786/470b.pdf | title= Making Headway Under Hellacious Circumstances | accessdate = 2008-06-23 }}</ref> However, after determining that AIDS was not isolated to the [[homosexual]] community,<ref name=MMWR1982b/> the term GRID became misleading and ''AIDS'' was introduced at a meeting in July 1982.<ref name=Kher>{{ cite news | author=Kher U | title=A Name for the Plague | work=Time | date=1982-07-27 | url=http://www.time.com/time/80days/820727.html |accessdate=2008-03-10 }}</ref> By September 1982 the CDC started using the name AIDS, and properly defined the illness.<ref name=MMWR1982c>{{ cite journal | author=Centers for Disease Control (CDC) | title=Update on acquired immune deficiency syndrome (AIDS)—United States. | journal=MMWR Morb Mortal Wkly Rep. | year=1982 | pages=507&ndash;508; 513&ndash;514 | volume=31 | issue=37 | pmid=6815471 }}</ref> A more controversial theory known as the [[OPV AIDS hypothesis]] suggests that the AIDS epidemic was inadvertently started in the late 1950s in the [[Belgian Congo]] by [[Hilary Koprowski]]'s research into a [[poliomyelitis]] [[vaccine]].<ref name=Curtis>{{ cite news | author=Curtis T | title=The origin of AIDS| work=Rolling Stone | year=1992 | pages=54&ndash;59, 61, 106, 108 | issue=626 | url=http://www.uow.edu.au/arts/sts/bmartin/dissent/documents/AIDS/Curtis92.html|accessdate=2008-03-10 }}</ref><ref name=Hooper>{{ cite book | author = Hooper E | year = 1999 | title = The River : A Journey to the Source of HIV and AIDS | edition = 1st | pages = 1&ndash;1070 | publisher = Little Brown & Co | location = Boston, MA | id = ISBN 0-316-37261-7 }}</ref> According to [[scientific consensus]], this scenario is not supported by the available evidence.<ref name=refuted>{{ cite journal | author = Worobey M, Santiago ML, Keele BF, et al |title = Origin of AIDS: contaminated polio vaccine theory refuted |journal=Nature | year=2004 | pages=820 | volume=428| issue=6985 | pmid=15103367 | doi=10.1038/428820a}}</ref><ref name=Berry>{{ cite journal | author = Berry N, Jenkins A, Martin J, et al |title = Mitochondrial DNA and retroviral RNA analyses of archival oral polio vaccine (OPV CHAT) materials: evidence of macaque nuclear sequences confirms substrate identity |journal=Vaccine | year=2005 | pages=1639&ndash;1648 | volume=23 | pmid=15705467 | doi=10.1016/j.vaccine.2004.10.038}}</ref><ref name=VaccineQA>{{ cite web | publisher=[[Centers for Disease Control and Prevention]] | date= 2004-03-23 | url=http://www.cdc.gov/nip/vacsafe/concerns/aids/poliovac-hiv-aids-qa.htm | title= Oral Polio Vaccine and HIV / AIDS: Questions and Answers | accessdate = 2006-11-20 }}</ref> A recent study states that HIV probably moved from [[Africa]] to [[Haiti]] and then entered the United States around 1969.<ref>{{cite journal |author=Gilbert MT, Rambaut A, Wlasiuk G, Spira TJ, Pitchenik AE, Worobey M |title=The emergence of HIV/AIDS in the Americas and beyond |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=104 |issue=47 |pages=18566–70 |year=2007 |pmid=17978186 |doi=10.1073/pnas.0705329104 }} </ref> ==Society and culture== ===Stigma=== [[Image:Ryan White.jpg|thumb|216px|right|[[Ryan White]] became a poster child for HIV after being expelled from school because of his infection.]] AIDS stigma exists around the world in a variety of ways, including [[shunning|ostracism]], [[Social rejection|rejection]], [[discrimination]] and avoidance of HIV infected people; compulsory HIV testing without prior [[consent]] or protection of [[confidentiality]]; violence against HIV infected individuals or people who are perceived to be infected with HIV; and the [[quarantine]] of HIV infected individuals.<ref name=UNAIDS2006Ch4>{{ cite book | publisher =[[Joint United Nations Programme on HIV/AIDS|UNAIDS]] | year = 2006 | title = 2006 Report on the global AIDS epidemic | chapter = The impact of AIDS on people and societies | chapterurl = http://data.unaids.org/pub/GlobalReport/2006/2006_GR_CH04_en.pdf | accessdate = 2006-06-14 | format= PDF }}</ref> Stigma-related violence or the fear of violence prevents many people from seeking HIV testing, returning for their results, or securing treatment, possibly turning what could be a manageable chronic illness into a death sentence and perpetuating the spread of HIV.<ref name=Ogden>{{ cite web | author =Ogden J, Nyblade L | publisher = [[International Center for Research on Women]] | year = 2005 | title = Common at its core: HIV-related stigma across contexts | url = http://www.icrw.org/docs/2005_report_stigma_synthesis.pdf | format = PDF | accessdate = 2007-02-15 }}</ref> AIDS stigma has been further divided into the following three categories: *''Instrumental AIDS stigma''&mdash;a reflection of the fear and apprehension that are likely to be associated with any deadly and transmissible illness.<ref name=Herek1999>{{ cite journal | author=Herek GM, Capitanio JP | journal=American Behavioral Scientist | year=1999 | url=http://psychology.ucdavis.edu/rainbow/html/abs99_sp.pdf | format= PDF | title=AIDS Stigma and sexual prejudice | accessdate = 2006-03-27 | volume=42 | issue=7 | pages=1130-1147 | doi=10.1177/0002764299042007006 }}</ref> *''Symbolic AIDS stigma''&mdash;the use of HIV/AIDS to express attitudes toward the social groups or lifestyles perceived to be associated with the disease.<ref name=Herek1999 /> *''Courtesy AIDS stigma''&mdash;stigmatization of people connected to the issue of HIV/AIDS or HIV- positive people.<ref name=Snyder>{{ cite journal | author=Snyder M, Omoto AM, Crain AL | title=Punished for their good deeds: stigmatization for AIDS volunteers | journal=American Behavioral Scientist | year=1999 | pages=1175&ndash;1192 | volume=42 | issue=7 | doi=10.1177/0002764299042007009 }}</ref> Often, AIDS stigma is expressed in conjunction with one or more other stigmas, particularly those associated with [[homosexuality]], [[bisexuality]], [[promiscuity]], and [[Intravenous drug use (recreational)|intravenous drug use]]. In many [[Developed country|developed countries]], there is an association between AIDS and homosexuality or bisexuality, and this association is correlated with higher levels of sexual prejudice such as [[homophobia|anti-homosexual]] attitudes.<ref name=Herek2002>{{cite journal |author=Herek GM, Capitanio JP, Widaman KF |title=HIV-related stigma and knowledge in the United States: prevalence and trends, 1991-1999 |journal=Am J Public Health |volume=92 |issue=3 |pages=371–7 |year=2002 |pmid=11867313 |doi= |url=http://psychology.ucdavis.edu/rainbow/html/ajph2002.pdf |accessdate=2008-03-10 }}</ref> There is also a perceived association between AIDS and all male-male sexual behavior, including sex between uninfected men.<ref name=Herek1999/> ===Economic impact=== {{main|Economic impact of AIDS}} [[Image:Life expectancy in some Southern African countries 1958 to 2003.png|right|295px|thumb|Changes in life expectancy in some hard-hit African countries. {{legend-line|red solid 2px|Botswana}}{{legend-line|darkgreen solid 2px|Zimbabwe}}{{legend-line|blue solid 2px|Kenya}}{{legend-line|black solid 2px|South Africa}}{{legend-line|grey solid 2px|Uganda}}]] HIV and AIDS affects [[economic growth]] by reducing the availability of [[human capital]].<ref name="Bell-et-al-2003">{{cite paper |author= Bell C, Devarajan S, Gersbach H |date=2003 |url=http://www1.worldbank.org/hiv_aids/docs/BeDeGe_BP_total2.pdf |title=The long-run economic costs of AIDS: theory and an application to South Africa |accessdate= 2008-04-28 |version= World Bank Policy Research Working Paper No. 3152 |format=PDF}}</ref> Without proper [[nutrition]], health care and medicine that is available in developed countries, large numbers of people are falling victim to AIDS. They will not only be unable to work, but will also require significant medical care. The forecast is that this will likely cause a collapse of economies and societies in countries with a significant AIDS populationi. In some heavily infected areas, the epidemic has left behind many [[orphan]]s cared for by elderly [[grandparent]]s.<ref name=Greener>{{cite book | author =Greener R | year = 2002 | title = State of The Art: AIDS and Economics | chapter = AIDS and macroeconomic impact | editor = S, Forsyth (ed.) | pages = 49&ndash;55 | publisher = IAEN }}</ref> The increased mortality in this region will result in a [[population decline|smaller skilled population]] and [[labor force]]. This smaller [[labor force]] will be predominantly young people, with reduced knowledge and [[work experience]] leading to reduced productivity. An increase in workers’ time off to look after sick family members or for [[sick leave]] will also lower productivity. Increased mortality will also weaken the mechanisms that generate human capital and [[investment]] in people, through loss of [[income]] and the death of parents. By killing off mainly young adults, AIDS seriously weakens the [[tax]]able population, reducing the resources available for [[public expenditure]]s such as education and health services not related to AIDS resulting in increasing pressure for the state's finances and slower growth of the economy. This results in a slower growth of the tax base, an effect that will be reinforced if there are growing expenditures on treating the sick, training (to replace sick workers), sick pay and caring for AIDS orphans. This is especially true if the sharp increase in adult mortality shifts the responsibility and blame from the family to the government in caring for these orphans.<ref name=Greener /> On the level of the household, AIDS results in both the loss of income and increased spending on healthcare by the household. The income effects of this lead to spending reduction as well as a substitution effect away from education and towards healthcare and funeral spending. A study in [[Côte d'Ivoire]] showed that households with an HIV/AIDS patient spent twice as much on medical expenses as other households.<ref name="WBank"> {{cite paper |author=Over M |title=The macroeconomic impact of AIDS in Sub-Saharan Africa, Population and Human Resources Department |publisher=The World Bank |date=1992 |url=http://www.worldbank.org/aidsecon/macro.pdf |format=PDF |accessdate=2008-05-03 }}</ref> ===AIDS denialism=== {{main|AIDS denialism}} A small group of activists, including several scientists who do not study HIV/AIDS, question the connection between HIV and AIDS,<ref name=Duesberg>{{cite journal | author=Duesberg PH | title=HIV is not the cause of AIDS | journal=Science | year=1988 | pages=514, 517 | volume=241 | issue=4865 | pmid=3399880 | doi=10.1126/science.3399880 }}</ref> the existence of HIV itself,<ref name=Papadopulos>{{ cite journal | author=Papadopulos-Eleopulos E, Turner VF, Papadimitriou J, et al | title=A critique of the Montagnier evidence for the HIV/AIDS hypothesis | journal=Med Hypotheses | year=2004 | pages=597&ndash;601 | volume=63 | issue=4 | pmid=15325002 | doi=10.1016/j.mehy.2004.03.025 }}</ref> or the validity of current testing and treatment methods. Though these claims have been examined and thoroughly rejected by the [[scientific community]],<ref name=consensus>For evidence of the [[scientific consensus]] that HIV is the cause of AIDS, see (for example): *{{cite journal |title=The Durban Declaration |journal=Nature |volume=406 |issue=6791 |pages=15&ndash;6 |year=2000 |pmid=10894520 |doi=10.1038/35017662|url=http://www.nature.com/nature/journal/v406/n6791/full/406015a0.html|accessdate=2008-05-03 |author=, }} *{{cite journal | author=Cohen J | title=The Duesberg Phenomenon: A Berkeley virologist and his supporters continue to argue that HIV is not the cause of AIDS. A 3-month investigation by Science evaluates their claims. | journal=Science | year=1994 | pages=1642&ndash;1649 | volume=266 | issue=5191 | url=http://www.sciencemag.org/feature/data/cohen/266-5191-1642a.pdf|format=PDF}} *{{cite web | publisher=[[National Institute of Allergy and Infectious Diseases]] | year= | url=http://www3.niaid.nih.gov/news/focuson/hiv/resources/ | title=Focus on the HIV-AIDS Connection: Resource links | accessdate = 2006-09-07 }} *{{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=}} *{{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&ndash;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 President [[Thabo Mbeki|Thabo Mbeki's]] embrace of AIDS denialism has been blamed for 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> ==Notes and references== <!--See http://en.wikipedia.org/wiki/Wikipedia:Footnotes for an explanation of how to generate footnotes using the <ref(erences/)> tags--> {{reflist|3}} <!-- I just copy/pasted the above code from another page. I don't --> <!-- know how it works; I just know it does something convenient. --> <!-- So please edit if any of it's inappropriate. -Qwerty0 4/15/08--> <!--================================================================--> <!-- Please follow wikipedia policy on external links. --> <!-- that can be found on the page WP:EL --> <!-- If you have a link that you want added please use the talk page--> <!-- to explain why you feel it should be included in the article. --> <!-- Doing so will let other editors understand what you are doing --> <!-- and will prevent misunderstandings from turning into reverts. --> <!--================================================================--> ==Further reading== *{{cite web |url=http://data.unaids.org/pub/EPISlides/2007/2007_epiupdate_en.pdf |title=2007 AIDS epidemic update |accessdate=2008-03-21 |publisher=UNAIDS |format=pdf |work= }} *{{cite web |url=http://data.unaids.org/pub/Report/2007/2006_unaids_annual_report_en.pdf |title=UNAIDS Annual Report - Making the money work |accessdate=2008-03-21 |publisher=UNAIDS |format=pdf |work= }} *{{cite web |url=http://data.unaids.org/pub/Report/2007/20070925_advocacy_grne2_en.pdf |title= Financial Resources Required to Achieve, Universal Access to HIV Prevention, Treatment Care and Support |accessdate=2008-03-21 |publisher=UNAIDS |format=pdf |work= }} *{{cite web |url=http://data.unaids.org/pub/Manual/2007/20070306_prevention_guidelines_towards_universal_access_en.pdf |title= Practical Guidelines for Intensifying HIV Prevention |accessdate=2008-03-21 |publisher=UNAIDS |format=pdf |work= }} *{{cite web |url=http://aidsinfo.nih.gov/contentfiles/AntiretroviralFormulations_FS_en.pdf |title= Antiretroviral Formulations |accessdate=2008-03-21 |publisher=US Department of Health and Human Services |format=pdf |work= }} *{{cite web |url=http://aidsinfo.nih.gov/contentfiles/ApprovedMedstoTreatHIV_FS_en.pdf |title= Approved Medications to Treat HIV Infection |accessdate=2008-03-21 |publisher=US Department of Health and Human Services |format=pdf |work= }} *{{cite web |url=http://aidsinfo.nih.gov/contentfiles/HIVLifeCycle_FS_en.pdf |title= The HIV Life Cycle |accessdate=2008-03-21 |publisher=US Department of Health and Human Services |format=pdf |work= }} ==External links== {{Spoken Wikipedia|AIDS.ogg|2006-06-12}} {{Sisterlinks|b=Sexual Health/Sexually Transmitted Diseases#HIV|commons=Category:AIDS|n=Category:AIDS|v=Sexually transmitted diseases#Viruses}} <!--==========================({{NoMoreLinks}})============================ | PLEASE BE CAUTIOUS IN ADDING MORE LINKS TO THIS ARTICLE. 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