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? Human immunodeficiency virus
Stylized rendering of a cross section of the human immunodeficiency virus
Virus classification
Group: Group VI (ssRNA-RT) Family: Retroviridae Genus: Lentivirus Species: Human immunodeficiency virus 1 Species: Human immunodeficiency virus 2

Human immunodeficiency virus (HIV) is a retrovirus that causes acquired immunodeficiency syndrome (AIDS), a condition in humans in which the immune system begins to fail, leading to life-threatening opportunistic infections. Previous names for the virus include human T-lymphotropic virus-III (HTLV-III), lymphadenopathy-associated virus (LAV), and AIDS-associated retrovirus (ARV).^[1][2] Image File history File links Padlock. ... Stylized rendering of a cross-section of the AIDS virus. ... Virus classification involves naming and placing viruses into a taxonomic system. ... ss-RNA RT is the single stranded Ribonucleic acid genome that is present in the HIV virus. ... Genera Alpharetrovirus Betaretrovirus Gammaretrovirus Deltaretrovirus Epsilonretrovirus Lentivirus Spumavirus A retrovirus is a virus which has a genome consisting of two identical plus sense RNA molecules. ... // Comments A lentivirus is a genus of slow viruses of the retroviridae family, characterized by long incubation period. ... The International Statistical Classification of Diseases and Related Health Problems (commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The following codes are used with International Statistical Classification of Diseases and Related Health Problems. ... The International Statistical Classification of Diseases and Related Health Problems (commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. ... Genera Alpharetrovirus Betaretrovirus Gammaretrovirus Deltaretrovirus Epsilonretrovirus Lentivirus Spumavirus A retrovirus is any virus belonging to the viral family Retroviridae. ... Acquired immune deficiency syndrome or acquired immunodeficiency syndrome (AIDS or Aids) is a collection of symptoms and infections resulting from the specific damage to the immune system caused by the human immunodeficiency virus (HIV). ... Trinomial name Homo sapiens sapiens Linnaeus, 1758 Humans, or human beings, are bipedal apes belonging to the mammalian species Homo sapiens (Latin for wise man or knowing man) under the family Hominidae (known as the great apes). ... The immune system protects the body from infection by pathogenic organisms. ... Groups I: dsDNA viruses II: ssDNA viruses III: dsRNA viruses IV: (+)ssRNA viruses V: (-)ssRNA viruses VI: ssRNA-RT viruses VII: dsDNA-RT viruses A virus (Latin, poison) is a microscopic particle that can infect the cells of a biological organism. ...

Infection with HIV occurs by the transfer of blood, semen, vaginal fluid, pre-ejaculate or breast milk. Within these body fluids HIV is present as both free virus particles and virus within infected immune cells. The three major routes of transmission are unprotected sexual intercourse, contaminated needles and transmission from an infected mother to her baby at birth or through breast milk. Screening of blood products for HIV in the developed world has largely eliminated transmission through blood transfusions or infected blood products in these countries. Human blood smear: a - erythrocytes; b - neutrophil; c - eosinophil; d - lymphocyte. ... Horse semen being collected for breeding purposes. ... Vaginal lubrication is the naturally produced lubricating fluid that reduces friction during sexual intercourse. ... Precum. ... Breast milk usually refers to the milk produced by a human female which is usually fed to infants by breastfeeding. ... Unprotected sex refers to any act of sexual intercourse in which the participants use no forms of protection from sexually transmitted diseases. ... Childbirth (also called labour, birth, partus or parturition) is the culmination of a human pregnancy with the emergence of a newborn infant from its mothers uterus. ... A developed country is a country that has achieved (currently or historically) a high degree of industrialization, and which enjoys the higher standards of living which wealth and technology make possible. ...

HIV infection in humans is now pandemic. As of January 2006, the Joint United Nations Programme on HIV/AIDS (UNAIDS) and the World Health Organization (WHO) estimate that AIDS has killed more than 25 million people since it was first recognized on December 1, 1981, making it one of the most destructive pandemics in recorded history. In 2005 alone, AIDS claimed an estimated 2.4-3.3 million lives, of which more than 570,000 were children. It is estimated that about 0.6% of the world's living population is infected with HIV.^[3] A third of these deaths are occurring in sub-Saharan Africa, retarding economic growth and increasing poverty.^[4] According to current estimates, HIV is set to infect 90 million people in Africa, resulting in a minimum estimate of 18 million orphans.^[5] Antiretroviral treatment reduces both the mortality and the morbidity of HIV infection, but routine access to antiretroviral medication is not available in all countries.^[6] This article is about large epidemics. ... 2006 is a common year starting on Sunday of the Gregorian calendar. ... The Joint United Nations Programme on HIV and AIDS, or UNAIDS, is the main advocate for accelerated, comprehensive and coordinated global action on the HIV epidemic. ... The World Health Organization (WHO) is a specialized agency of the United Nations, acting as a coordinating authority on international public health, headquartered in Geneva, Switzerland. ... December 1 is the 335th (in leap years the 336th) day of the year in the Gregorian calendar. ... 1981 (MCMLXXXI) was a common year starting on Thursday of the Gregorian calendar. ... Acquired Immune Deficiency Syndrome (AIDS) has killed more than 25 million people since it was first recognized in 1981, making it one of the most destructive epidemics in recorded history. ... A world map showing the continent of Africa. ... Accumulated GDP growth for various countries. ... A world map showing the continent of Africa. ... Orphans, by Thomas Kennington An orphan (from the Greek ορφανός) is a person (or animal), who has lost one or both parents often through death. ... Antiretroviral drugs are medications for the treatment of infection by retroviruses, primarily HIV. Different classes of antiretroviral drugs act at different stages of the HIV life cycle. ... In medicine, epidemiology and actuarial science, the term morbidity can refer to the state of being diseased (from Latin morbidus: sick, unhealthy), the degree or severity of a disease, the prevalence of a disease: the total number of cases in a particular population at a particular point in time, the...

HIV primarily infects vital cells in the human immune system such as helper T cells (specifically CD4⁺ T cells), macrophages and dendritic cells. HIV infection leads to low levels of CD4⁺ T cells through three main mechanisms: firstly, direct viral killing of infected cells; secondly, increased rates of apoptosis in infected cells; and thirdly, killing of infected CD4⁺ T cells by CD8 cytotoxic lymphocytes that recognize infected cells. When CD4⁺ T cell numbers decline below a critical level, cell-mediated immunity is lost, and the body becomes progressively more susceptible to opportunistic infections. If untreated, eventually most HIV-infected individuals develop AIDS and die; however about one in ten remain healthy for many years, with no noticeable symptoms.^[7] Treatment with anti-retrovirals, where available, increases the life expectancy of people infected with HIV. It is hoped that current and future treatments may allow HIV-infected individuals to achieve a life expectancy approaching that of the general public (see Treatment). Trinomial name Homo sapiens sapiens Linnaeus, 1758 Humans, or human beings, are bipedal apes belonging to the mammalian species Homo sapiens (Latin for wise man or knowing man) under the family Hominidae (known as the great apes). ... The immune system protects the body from infection by pathogenic organisms. ... A helper (or TH) T cell is a T cell (a type of white blood cell) which has on its surface antigen receptors that can bind to fragments of antigens displayed by the Class II MHC molecules found on professional antigen-presenting cells (APCs). ... Macrophages (Greek: big eaters) are cells found in tissues that are responsible for phagocytosis of pathogens, dead cells and cellular debris. ... Dendritic cells (DC) are immune cells and form part of the mammal immune system. ... A cell undergoing apoptosis. ... A cytotoxic T cell (also known as TC, CTL or killer T cell) belongs to a sub-group of T lymphocytes (a type of white blood cell) which are capable of inducing the death of infected somatic or tumor cells; they kill cells that are infected with viruses (or other... Cell-mediated immunity is an immune response that does not involve antibodies but rather involves the activation of macrophages and NK-cells, the production of antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen. ...

Origin and discovery

Main article: AIDS origin

The AIDS epidemic was discovered June 5, 1981, when the U.S. Centers for Disease Control and Prevention reported a cluster of Pneumocystis carinii pneumonia (now classified as Pneumocystis jiroveci pneumonia) in five homosexual men in Los Angeles.^[8] The disease was originally dubbed GRID, or Gay-Related Immune Deficiency, but health authorities soon realized that nearly half of the people identified with the syndrome were not homosexual men. In 1982, the CDC introduced the term AIDS to describe the newly recognized syndrome, though it was still casually referred to as GRID. Scanning electron micrograph of HIV-1 budding from cultured lymphocyte. ... June 5 is the 156th day of the year in the Gregorian calendar (157th in leap years), with 209 days remaining. ... 1981 (MCMLXXXI) was a common year starting on Thursday of the Gregorian calendar. ... The Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia, is recognized as the leading United States agency for protecting the public health and safety of people. ... Pneumocystis jiroveci pneumonia or Pneumocystis pneumonia (PCP) is a form of pneumonia caused by the yeast-like fungal microorganism Pneumocystis jiroveci (sometimes spelled jirovecii and formerly classified as Pneumocystis carinii). ... Flag Seal Nickname: City of Angels Location Location within Los Angeles County in the state of California Coordinates , Government State County California Los Angeles County Mayor Antonio Villaraigosa (D) Geographical characteristics Area     City 1,290. ... In medicine, immune deficiency (or immunodeficiency) is a state where the immune system is incapable of defending the organism from infectious disease. ...

In 1983, scientists led by Luc Montagnier at the Pasteur Institute in France first discovered the virus that causes AIDS.^[9] They called it lymphadenopathy-associated virus (LAV). A year later a team led by Robert Gallo of the United States confirmed the discovery of the virus, but they renamed it human T lymphotropic virus type III (HTLV-III).^[10] The dual discovery led to considerable scientific disagreement, and it was not until President Mitterrand of France and President Reagan of the USA met that the major issues were resolved. In 1986, both the French and the US names for the virus itself were dropped in favour of the new term, human immunodeficiency virus (HIV).^[2] Luc Montagnier (born 1932) is a French virologist. ... The Pasteur Institute (French: Institut Pasteur) is a French non-profit private foundation dedicated to the study of biology, microorganisms, diseases and vaccines. ... Dr. Robert C. Gallo Robert Charles Gallo (born March 23, 1937) is a U.S. biomedical researcher. ... (October 26, 1916 – January 8, 1996) was a French politician. ... Ronald Wilson Reagan GCB (February 6, 1911 – June 5, 2004) was the 40th President of the United States (1981–1989) and the 33rd Governor of California (1967–1975). ...

HIV was classified as a member of the genus lentivirus,^[11] part of the family of retroviridae.^[12] Lentiviruses have many common morphologies and biological properties. Many species are infected by lentiviruses, which are characteristically responsible for long-duration illnesses with a long incubation period.^[13] Lentiviruses are transmitted as single-stranded, positive-sense, enveloped RNA viruses. Upon entry of the target cell, the viral RNA genome is converted to double-stranded DNA by a virally encoded reverse transcriptase that is present in the virus particle. This viral DNA is then integrated into the cellular DNA by a virally encoded integrase so that the genome can be transcribed. Once the virus has infected the cell, two pathways are possible: either the virus becomes latent and the infected cell continues to function, or the virus becomes active and replicates, and a large number of virus particles are liberated that can then infect other cells. // Comments A lentivirus is a genus of slow viruses of the retroviridae family, characterized by long incubation period. ... Genera Alpharetrovirus Betaretrovirus Gammaretrovirus Deltaretrovirus Epsilonretrovirus Lentivirus Spumavirus A retrovirus is a virus which has a genome consisting of two identical plus sense RNA molecules. ... An RNA virus is a virus that either uses RNA as its genetic material, or whose genetic material passes through an RNA intermediate during replication. ... In biology the genome of an organism is the whole hereditary information of an organism that is encoded in the DNA (or, for some viruses, RNA). ... For other uses, see DNA (disambiguation). ... In biochemistry, a reverse transcriptase, also known as RNA-directed DNA polymerase, is a DNA polymerase enzyme that transcribes single-stranded RNA into double-stranded DNA. Normal transcription involves the synthesis of RNA from DNA, hence reverse transcription is the reverse of this, as it synthesises DNA from RNA. Reverse... Integrase is a protein produced by a virus that enables genetic material that is helpful to the virus, proviral DNA, to be integrated into the DNA of the infected cell. ... Look up Transcription in Wiktionary, the free dictionary. ... Incubation period is the time elapsed between exposure to a pathogenic organism and when symptoms and signs are first apparent. ...

Two species of HIV infect humans: HIV-1 and HIV-2. HIV-1 is thought to have originated in southern Cameroon after jumping from wild chimpanzees (Pan troglodytes troglodytes) to humans during the twentieth century.^[14][15] HIV-2 may have originated from the Sooty Mangabey (Cercocebus atys), an Old World monkey of Guinea-Bissau, Gabon, and Cameroon.^[16] HIV-1 is more virulent. It is easily transmitted and is the cause of the majority of HIV infections globally. HIV-2 is less transmittable and is largely confined to West Africa.^[16] HIV-1 is the virus that was initially discovered and termed LAV. Species Pan troglodytes Pan paniscus Chimpanzees, also called chimps, are the common name for two species in the genus Pan. ... (19th century - 20th century - 21st century - more centuries) Decades: 1900s 1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s The 20th century lasted from 1901 to 2000 in the Gregorian calendar (often from (1900 to 1999 in common usage). ... Binomial name Cercocebus atys (Audebert, 1797) The Sooty Mangabey (Cercocebus atys), also called the White-collared Mangabey, is an Old World monkey of Guinea Bissau, Gabon, and Cameroon. ...  Western Africa (UN subregion)  Maghreb West Africa or Western Africa is the westernmost region of the African continent. ...

Three of the earliest known instances of HIV-1 infection are as follows:

1. A plasma sample taken in 1959 from an adult male living in what is now the Democratic Republic of Congo.^[17]
2. HIV found in tissue samples from a 15 year old African-American teenager who died in St. Louis in 1969.^[18]
3. HIV found in tissue samples from a Norwegian sailor who died around 1976.^[19]

Although a variety of theories exist explaining the transfer of HIV to humans, no single hypothesis is widely accepted, and the topic remains controversial. Freelance journalist Tom Curtis discussed one controversial possibility for the origin of HIV/AIDS in a 1992 Rolling Stone magazine article. He put forward what is now known as the OPV AIDS hypothesis, which suggests that AIDS was inadvertently caused in the late 1950s in the Belgian Congo by Hilary Koprowski's research into a polio vaccine.^[20] Although subsequently retracted due to libel issues surrounding its claims, the Rolling Stone article motivated another freelance journalist, Edward Hooper, to probe more deeply into this subject. Hooper's research resulted in his publishing a 1999 book, The River, in which he alleged that an experimental oral polio vaccine prepared using chimpanzee kidney tissue was the route through which simian immunodeficiency virus (SIV) crossed into humans to become HIV, thus starting the human AIDS pandemic.^[21] This theory is contradicted by an analysis of genetic mutation in primate lentivirus strains that indicates with 95% certainty that the origin of the HIV-1 strain dates to about 1930.^[22] Tom Curtis (born 1973, Ilkeston) is a professional football player, & currently plays for Notts County. ... Rolling Stone is an American magazine devoted to music, politics, and popular culture that is published bi-weekly. ... According to the oral polio vaccine (OPV) AIDS hypothesis, the AIDS pandemic originated from live polio vaccines prepared in chimpanzee tissue cultures (at least some of which were almost certainly contaminated with chimpanzee SIV) which were administered to up to one million Africans between 1957 and 1960. ... Capital Léopoldville Government Protectorate Created 1908 Dissolved 1960 Official language(s) French, Dutch The Belgian Congo was the formal title of present-day Democratic Republic of the Congo (DRC) between King Léopold IIs formal relinquishment of personal control over the state to Belgium on 15 November 1908... Hilary Koprowski (b. ... Poliomyelitis (polio), or infantile paralysis, is a viral paralytic disease. ... A vaccine is an antigenic preparation used to establish immunity to a disease. ... In English and American law, and systems based on them, libel and slander are two forms of defamation (or defamation of character), which is the tort or delict of making a false statement of fact that injures someones reputation. ... Edward Hooper is a British journalist. ... Edward Hooper is a British journalist. ... Poliomyelitis (polio), or infantile paralysis, is a viral paralytic disease. ... A vaccine is an antigenic preparation used to establish immunity to a disease. ... Type Species Simia troglodytes Blumenbach, 1775 Species Pan troglodytes Pan paniscus Chimpanzee, often shortened to chimp, is the common name for the two extant species in the genus Pan. ... To meet Wikipedias quality standards, this article or section may require cleanup. ...

Transmission

For more details on this topic, see AIDS transmission and prevention

Since the beginning of the pandemic, three main transmission routes for HIV have been identified: Acquired immune deficiency syndrome or acquired immunodeficiency syndrome (AIDS or Aids) is a collection of symptoms and infections resulting from the specific damage to the immune system caused by the human immunodeficiency virus (HIV). ... This article is about large epidemics. ...

• Sexual route. The majority of HIV infections are acquired through unprotected sexual relations. Sexual transmission can occur when infected sexual secretions of one partner come into contact with the rectal, genital or oral mucous membranes of another.
• Blood or blood product route. This transmission route can account for infections in intravenous drug users, hemophiliacs and recipients of blood transfusions (though most transfusions are checked for HIV in the developed world) and blood products. It is also of concern for persons receiving medical care in regions where there is prevalent substandard hygiene in the use of injection equipment, such as the reuse of needles in Third World countries. Health care workers such as nurses, laboratory workers, and doctors, have also been infected, although this occurs more rarely. People who give and receive tattoos, piercings and scarification procedures can also be at risk of infection.
• Mother-to-child transmission (MTCT). 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 the mother and child is 25%.^[25] However, where drug treatment and Cesarian section are available, this can be reduced to 1%.^[25] Breast feeding also presents a risk of infection for the baby.

HIV-2 is transmitted much less frequently by the MTCT and sexual route than HIV-1. The mucous membranes (or mucosa) are linings of ectodermic origin, covered in epithelium, that line various body cavities and internal organs. ... Haemophilia or hemophilia is the name of any of several hereditary genetic illnesses that impair the bodys ability to control bleeding. ... Donating blood Blood transfusion is the process of transferring blood or blood-based products from one person into the circulatory system of another. ... A caesarean section (cesarean section AE), is a surgical incision through a mothers abdomen (laparotomy) and uterus (hysterotomy) to deliver one or more fetuses. ...

HIV has been found at low concentrations in the saliva, tears and urine of infected individuals, but the risk of transmission by these secretions is negligible. The use of physical barriers such as the latex condom is widely advocated to reduce the sexual transmission of HIV. Spermicide when used alone or with vaginal contraceptives like a diaphragm actually increases the male to female transmission rate due to inflammation of the vagina, and should not be considered a barrier to infection.^[31] Current research is clarifying the relationship between male circumcision and HIV in differing social and cultural contexts.^[32] Even though male circumcision may lead to a reduction of infection risk in heterosexual men by up to 60%,^[33] UNAIDS believes that it is premature to recommend male circumcision as part of HIV prevention programs.^[34] South African medical experts are concerned that the repeated use of unsterilized blades in the ritual circumcision of adolescent boys may be spreading HIV.^[35] Saliva is the watery and usually somewhat frothy substance produced in the mouths of some animals, including humans. ... The tear system (click for labels) Tears are a liquid produced by the bodys process of lacrimation to clean and lubricate the eyes. ... This article or section is in need of attention from an expert on the subject. ... The LaTeX logo, typeset with LaTeX , written as LaTeX in plain text, is a document preparation system for the (TeX) typesetting program. ... A 67 m long condom on the Obelisk of Buenos Aires, Argentina, part of an awareness campaign for the 2005 World AIDS Day A condom is a type of funky rubber hat that you can wear on your head. ... Spermicide is a substance that kills sperm, inserted vaginally prior to intercourse to prevent pregnancy. ... A diaphragm is some sort of separating membrane. ... Seixas Family circumcision set and trunk, ca. ...

Structure and genome

Main article: HIV structure and genome

Diagram of HIV

HIV is different in structure from other retroviruses. It is about 120 nm in diameter (120 billionths of a meter; around 60 times smaller than a red blood cell) and roughly spherical.^[36] The genome and proteins of HIV have been the subject of extensive research in the twenty years since the discovery of the virus. ... Image File history File links 800px-HIV_Viron. ... Image File history File links 800px-HIV_Viron. ...

It is composed of two copies of positive single-stranded RNA that codes for the virus's nine genes enclosed by a conical capsid composed of 2,000 copies of the viral protein, p24.^[37] The single-stranded RNA is tightly bound to nucleocapsid proteins, p7 and enzymes needed for the development of the virion such as reverse transcriptase, proteases and integrase. A matrix composed of the viral protein p17 surrounds the capsid ensuring the integrity of the virion particle.^[37] This is, in turn, surrounded by the viral envelope which is composed of two layers of fatty molecules called phospholipids taken from the membrane of a human cell when a newly formed virus particle buds from the cell. Embedded in the viral envelope are proteins from the host cell and about 70 copies of a complex HIV protein that protrudes through the surface of the virus particle.^[37] This protein, known as Env, consists of a cap made of three molecules called glycoprotein (gp) 120, and a stem consisting of three gp41 molecules that anchor the structure into the viral envelope.^[38] This glycoprotein complex enables the virus to attach to and fuse with target cells to initiate the infectious cycle.^[38] Both these surface proteins, especially gp120, have been considered as targets of future treatments or vaccines against HIV.^[39] Ribonucleic acid (RNA) is a nucleic acid polymer consisting of nucleotide monomers. ... This stylistic schematic diagram shows a gene in relation to the double helix structure of DNA and to a chromosome (right). ... P24 or P-24 may refer to: P24 (band), a German band p24, a protein of the HIV virus; see HIV structure and genome Lockheed YP-24, a 1930s prototype two-seat fighter aircraft Category: ... In biochemistry, a reverse transcriptase, also known as RNA-directed DNA polymerase, is a DNA polymerase enzyme that transcribes single-stranded RNA into double-stranded DNA. Normal transcription involves the synthesis of RNA from DNA, hence reverse transcription is the reverse of this, as it synthesises DNA from RNA. Reverse... Proteases (proteinases, peptidases, or proteolytic enzymes) are enzymes that break peptide bonds between amino acids of proteins. ... Integrase is a protein produced by a virus that enables genetic material that is helpful to the virus, proviral DNA, to be integrated into the DNA of the infected cell. ... Two schematic representations of a phospholipid. ... An HIV envelope glycoprotein that is anchored to the membrane through non-covalent bonds along with gp41, both coming from a cleaved protein, gp160. ... The genome and proteins of HIV have been the subject of extensive research since the discovery of the virus in 1983. ...

Of the nine genes that are encoded within the RNA genome, three of these genes, gag, pol, and env, contain information needed to make the structural proteins for new virus particles.^[37] env, for example, codes for a protein called gp160 that is broken down by a viral enzyme to form gp120 and gp41. The six remaining genes, tat, rev, nef, vif, vpr, and vpu (or vpx in the case of HIV-2), are regulatory genes for proteins that control the ability of HIV to infect cells, produce new copies of virus (replicate), or cause disease.^[37] The protein encoded by nef, for instance, appears necessary for the virus to replicate efficiently, and the vpu-encoded protein influences the release of new virus particles from infected cells.^[37] The ends of each strand of HIV RNA contain an RNA sequence called the long terminal repeat (LTR). Regions in the LTR act as switches to control production of new viruses and can be triggered by proteins from either HIV or the host cell.^[37]

Tropism

The term viral tropism refers to which cell types HIV infects. HIV can infect a variety of immune cells such as CD4⁺ T cells, macrophages, and microglial cells. HIV-1 entry to macrophages and CD4⁺ T cells is mediated through interaction of the virion envelope glycoproteins (gp120) with the CD4 molecule on the target cells and also with chemokine coreceptors.^[38] A helper (or TH) T cell is a T cell (a type of white blood cell) which has on its surface antigen receptors that can bind to fragments of antigens displayed by the Class II MHC molecules found on professional antigen-presenting cells (APCs). ... A macrophage of a mouse stretching its arms to engulf two particles, possibly pathogens Macrophages (Greek: big eaters, makros = long, phagein = eat) are white blood cells, more specifically phagocytes, acting in the nonspecific defense as well as the specific defense system of vertebrate animals. ... Microglia are a type of glial cell that act as the immune cells of the Central nervous system (CNS). ... Chemokines are a family of pro-inflammatory activation-inducible cytokines, or small protein signals secreted by cells. ...

Macrophage (M-tropic) strains of HIV-1, or non-syncitia-inducing strains (NSI) use the β-chemokine receptor CCR5 for entry and are thus able to replicate in macrophages and CD4⁺ T cells.^[40] This CCR5 coreceptor is used by almost all primary HIV-1 isolates regardless of viral genetic subtype. Indeed, macrophages play a key role in several critical aspects of HIV infection. They appear to be the first cells infected by HIV and perhaps the source of HIV production when CD4⁺ cells become depleted in the patient. Macrophages and microglial cells are the cells infected by HIV in the central nervous system. In tonsils and adenoids of HIV-infected patients, macrophages fuse into multinucleated giant cells that produce huge amounts of virus. In biology, a syncytium is a large region of cytoplasm that contains many nuclei. ... CCR5, short for chemokine (C-C motif) receptor 5, is a chemokine receptor. ... A diagram showing the CNS: 1. ...

T-tropic isolates, or syncitia-inducing (SI) strains replicate in primary CD4⁺ T cells as well as in macrophages and use the α-chemokine receptor, CXCR4, for entry.^[40][41][42] The α-chemokine, SDF-1, a ligand for CXCR4, suppresses replication of T-tropic HIV-1 isolates. It does this by down-regulating the expression of CXCR4 on the surface of these cells. HIV that use only the CCR5 receptor are termed R5, those that only use CXCR4 are termed X4, and those that use both, X4R5. However, the use of coreceptor alone does not explain viral tropism, as not all R5 viruses are able to use CCR5 on macrophages for a productive infection^[40] and HIV can also infect a subtype of myeloid dendritic cells,^[43] which probably constitute a reservoir that maintains infection when CD4⁺ T cell numbers have declined to extremely low levels. In biology, a syncytium is a large region of cytoplasm that contains many nuclei. ... CXCR4, also called fusin, is an alpha-chemokine receptor specific for stromal-derived-factor-1 (SDF-1). ... The R5 assault rifle is, along with the R4, one of the primary assault rifles in use by the military of South Africa. ... X4 or X-4 may be: Mega Man X4, a video game for the Playstation and Sega Saturn T cell tropic HIV are termed X4 X-4 Bantam Ruhrstahl X-4 A common name for petroleum ether Category: ... Dendritic cells (DC) are immune cells and form part of the mammalian immune system. ...

Some people are resistant to certain strains of HIV.^[44] One example of how this occurs is people with the CCR5-Δ32 mutation; these people are resistant to infection with R5 virus as the mutation stops HIV from binding to this coreceptor, reducing its ability to infect target cells. The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ...

Heterosexual intercourse is the major mode of HIV transmission. Both X4 and R5 HIV are present in the seminal fluid which is passed from partner to partner. The virions can then infect numerous cellular targets and disseminate into the whole organism. However, a selection process leads to a predominant transmission of the R5 virus through this pathway.^[45][46][47] How this selective process works is still under investigation, but one model is that spermatozoa may selectively carry R5 HIV as they possess both CCR3 and CCR5 but not CXCR4 on their surface^[48] and that genital epithelial cells preferentially sequester X4 virus.^[49] In patients infected with subtype B HIV-1, there is often a co-receptor switch in late-stage disease and T-tropic variants appear that can infect a variety of T cells through CXCR4.^[50] These variants then replicate more aggressively with heightened virulence that causes rapid T cell depletion, immune system collapse, and opportunistic infections that mark the advent of AIDS.^[51] Thus, during the course of infection, viral adaptation to the use of CXCR4 instead of CCR5 may be a key step in the progression to AIDS. A number of studies with subtype B-infected individuals have determined that between 40 and 50% of AIDS patients can harbour viruses of the SI, and presumably the X4, phenotype.^[52][53] Coition of a Hemisected Man and Woman (c. ... Male Anatomy The prostate is a gland that is part of male mammalian sex organs. ... Schematic diagram of a sperm cell, showing the (1) acrosome, (2) cell membrane, (3) nucleus, (4) mitochondria, and (5) flagellum (tail) A sperm cell, or spermatozoon ( spermatozoa) (in Greek: sperm = semen and zoon = alive), is the haploid cell that is the male gamete. ... In zootomy, epithelium is a tissue composed of a layer of cells. ...

Replication cycle

The HIV replication cycle

The immature and mature forms of HIV

Download high resolution version (1042x895, 161 KB)Source: Originally from GFDL image http://de. ... Download high resolution version (1042x895, 161 KB)Source: Originally from GFDL image http://de. ...

Entry to the cell

HIV enters macrophages and CD4⁺ T cells by the adsorption of glycoproteins on its surface to receptors on the target cell followed by fusion of the viral envelope with the cell membrane and the release of the HIV capsid into the cell.^[54][55] A glycoprotein is a macromolecule composed of a protein and a carbohydrate (a sugar). ...

The interactions of the trimeric envelope complex (gp160 spike, discussed above) and both CD4 and a chemokine receptor (generally either CCR5 or CXCR4 but others are known to interact) on the cell surface.^[54][55] The gp160 spike contains binding domains for both CD4 and chemokine receptors.^[54][55] The first step in fusion involves the high-affinity attachment of the CD4 binding domains of gp120 to CD4. Once gp120 is bound with the CD4 protein, the envelope complex undergoes a structural change, exposing the chemokine binding domains of gp120 and allowing them to interact with the target chemokine receptor.^[54][55] This allows for a more stable two-pronged attachment, which allows the N-terminal fusion peptide gp41 to penetrate the cell membrane.^[54][55] Repeat sequences in gp41, HR1 and HR2 then interact, causing the collapse of the extracellular portion of gp41 into a hairpin. This loop structure brings the virus and cell membranes close together, allowing fusion of the membranes and subsequent entry of the viral capsid.^[54][55] CD4 (cluster of differentiation 4) is a molecule that is expressed on the surface of T helper cells (as well as regulatory T cells and dendritic cells). ...

Once HIV has bound to the target cell, the HIV RNA and various enzymes, including reverse transcriptase, integrase and protease, are injected into the cell.^[54] Ribonucleic acid (RNA) is a nucleic acid polymer consisting of nucleotide monomers. ... Neuraminidase ribbon diagram An enzyme (in Greek en = in and zyme = blend) is a protein, or protein complex, that catalyzes a chemical reaction and also controls the 3D orientation of the catalyzed substrates. ...

HIV can infect dendritic cells (DCs) by this CD4-CCR5 route, but another route using mannose-specific C-type lectin receptors such as DC-SIGN can also be used.^[56] DCs are one of the first cells encountered by the virus during sexual transmission. They are currently thought to play an important role by transmitting HIV to T cells once the virus has been captured in the mucosa by DCs.^[57] Dendritic cells (DC) are immune cells and form part of the mammal immune system. ... A C-type lectin receptor present mainly on myeloid and pre-plasmacytoid dendritic cells that mediates dendritic cell rolling interactions with blood endothelium and activation of CD4+ T cells, as well as recognition of pathogen haptens. ... The mucous membranes (or mucosa) are linings of ectodermic origin, covered in epithelium, that line various body cavities and internal organs. ...

Replication and transcription

Once the viral capsid enters the cell, an enzyme called reverse transcriptase liberates the single-stranded (+)RNA from the attached viral proteins and copies it into a complementary DNA of 9 kb size.^[58] This process of reverse transcription is extremely error-prone and it is during this step that mutations may occur. Such mutations may cause drug resistance. The reverse transcriptase then makes a complementary DNA strand to form a double-stranded viral DNA intermediate (vDNA). This vDNA is then transported into the cell nucleus. The integration of the viral DNA into the host cell's genome is carried out by another viral enzyme called integrase.^[58] Ribbon diagram of the enzyme TIM, surrounded by the space-filling model of the protein. ... In biochemistry, a reverse transcriptase, also known as RNA-directed DNA polymerase, is a DNA polymerase enzyme that transcribes single-stranded RNA into double-stranded DNA. Normal transcription involves the synthesis of RNA from DNA, hence reverse transcription is the reverse of this, as it synthesises DNA from RNA. Reverse... Ribonucleic acid (RNA) is a nucleic acid polymer consisting of nucleotide monomers. ... For other uses, see DNA (disambiguation). ... In the context of virology, resistance or drug resistance refers to the lack of response of a population of viruses to an antiviral drug or treatment. ... The eukaryotic cell nucleus. ... In biology the genome of an organism is the whole hereditary information of an organism that is encoded in the DNA (or, for some viruses, RNA). ... Integrase is a protein produced by a virus that enables genetic material that is helpful to the virus, proviral DNA, to be integrated into the DNA of the infected cell. ...

This integrated viral DNA may then lie dormant, in the latent stage of HIV infection.^[58] To actively produce the virus, certain cellular transcription factors need to be present, the most important of which is NF-κB (NF kappa B), which is upregulated when T cells become activated.^[59] This means that those cells most likely to be killed by HIV are in fact those currently fighting infection. In the context of genetics, a transcription factor is a regulatory protein that initiates the transcription of certain genes upon binding with DNA. The binding of a transcription factor to a specific DNA sequence can result in either an increased rate of transcription of the gene, known as activated transcription... NF-κB, or Nuclear Factor kappa B, is a nuclear transcription factor found in all cell types and is involved in cellular responses to stimuli such as stress, cytokines, free radicals, ultraviolet irradiation, and bacterial or viral antigens. ...

In this replication process, the integrated provirus is copied to mRNA which is then spliced into smaller pieces. These small pieces produce the regulatory proteins Tat (which encourages new virus production) and Rev. As Rev accumulates it gradually starts to inhibit mRNA splicing.^[60] At this stage, the structural proteins Gag and Env are produced from the full-length mRNA. The full-length RNA is actually the virus genome; it binds to the Gag protein and is packaged into new virus particles. A provirus is a retrovirus that has integrated itself into the DNA of a host cell. ... The interaction of mRNA in a eukaryote cell. ... In genetics, splicing is a modification of genetic information after transcription, in which introns are removed and exons are joined. ... Tat may refer to: The Tats, an Iranian ethnic group from the Caucasus. ... REV is a cd by ten foot pole. ... The interaction of mRNA in a eukaryote cell. ... In genetics, splicing is a modification of genetic information prior to translation. ...

HIV-1 and HIV-2 appear to package their RNA differently; HIV-1 will bind to any appropriate RNA whereas HIV-2 will preferentially bind to the mRNA which was used to create the Gag protein itself. This may mean that HIV-1 is better able to mutate (HIV-1 infection progresses to AIDS faster than HIV-2 infection and is responsible for the majority of global infections).

Assembly and release

The final step of the viral cycle, assembly of new HIV-1 virons, begins at the plasma membrane of the host cell. The Env polyprotein (gp160) goes through the endoplasmic reticulum and is transported to the Golgi complex where it is cleaved by protease and processed into the two HIV envelope glycoproteins gp41 and gp120. These are transported to the plasma membrane of the host cell where gp41 anchors the gp120 to the membrane of the infected cell. The Gag (p55) and Gag-Pol (p160) polyproteins also associate with the inner surface of the plasma membrane along with the HIV genomic RNA as the forming virion begins to bud from the host cell. Maturation either occurs in the forming bud or in the immature virion after it buds from the host cell. During maturation, HIV proteases cleave the polyproteins into individual functional HIV proteins and enzymes. The various structural components then assemble to produce a mature HIV virion.^[61] This cleavage step can be inhibited by protease inhibitors. The mature virus is then able to infect another cell. The endoplasmic reticulum (endoplasmic meaning within the cytoplasm, reticulum meaning little net in Latin) or ER is an organelle found in all eukaryotic cells that is an interconnected network of tubules, vesicles and cisternae that is responsible for several specialized functions: Protein translation, folding, and transport of proteins (e. ... In cell biology, the Golgi apparatus, Golgi body, Golgi complex, or dictyosome is an organelle found in most eukaryotic cells, including those of plants, animals, and fungi. ... Proteases (proteinases, peptidases, or proteolytic enzymes) are enzymes that break peptide bonds between amino acids of proteins. ... Drawing of a cell membrane A component of every biological cell, the cell membrane (or plasma membrane) is a thin and structured bilayer of phospholipid and protein molecules that envelopes the cell. ...

Genetic variability

The phylogenetic tree of the SIV and HIV (click on image for a detailed description).

Map showing HIV-1 subtype prevalence. The bigger the pie chart, the more infections are present.

HIV differs from many other viruses as it has very high genetic variability. This diversity is a result of its fast replication cycle, with the generation of 10⁹ to 10¹⁰ virions every day, coupled with a high mutation rate of approximately 3 x 10^-5 per nucleotide base per cycle of replication and recombinogenic properties of reverse transcriptase.^[62] This complex scenario leads to the generation of many variants of HIV in a single infected patient in the course of one day.^[62] This variability is compounded when a single cell is simultaneously infected by two or more different strains of HIV. When simultaneous infection occurs, the genome of progeny virions may be composed of RNA strands from two different strains. This hybrid virion then infects a new cell where it undergoes replication. As this happens, the reverse transcriptase, by jumping back and forth between the two different RNA templates, will generate a newly synthesized retroviral DNA sequence that is a recombinant between the two parental genomes.^[62] This recombination is most obvious when it occurs between subtypes.^[62]. Image File history File links Download high resolution version (1681x1460, 173 KB)Source: Theoretical Biology and Biophysics Group, Los Alamos National Laboratory. ... Image File history File links Download high resolution version (1681x1460, 173 KB)Source: Theoretical Biology and Biophysics Group, Los Alamos National Laboratory. ... Image File history File links Download high resolution version (960x720, 46 KB)Map shows HIV-1 subtype prevalence in 2003. ... Image File history File links Download high resolution version (960x720, 46 KB)Map shows HIV-1 subtype prevalence in 2003. ... Human immunodeficiency virus or HIV is a retrovirus that causes Acquired Immunodeficiency Syndrome (AIDS), a condition in which the immune system begins to fail, leading to life-threatening opportunistic infections. ... It has been suggested that chromosomal crossover be merged into this article or section. ...

The closely related simian immunodeficiency virus (SIV) exhibits a somewhat different behavior: in its natural hosts, African green monkeys and sooty mangabeys, the retrovirus is present in high levels in the blood, but evokes only a mild immune response^[63], does not cause the development of simian AIDS^[64], and does not undergo the extensive mutation and recombination typical of HIV^[65]. By contrast, infection of heterologous hosts (rhesus or cynomologus macaques) with SIV results in the generation of genetic diversity that is on the same order as HIV in infected humans; these heterologous hosts also develop simian AIDS^[66]. The relationship, if any, between genetic diversification, immune response, and disease progression is unknown. To meet Wikipedias quality standards, this article or section may require cleanup. ... Species Chlorocebus sabaceus Chlorocebus aethiops Chlorocebus djamdjamensis Chlorocebus tantalus Chlorocebus pygerythrus Chlorocebus cynosuros The vervet monkeys or green monkeys are primates from the family of Old World monkeys. ... Binomial name Cercocebus atys (Audebert, 1797) The Sooty Mangabey (Cercocebus atys), also called the White-collared Mangabey, is an Old World monkey of Guinea Bissau, Gabon, and Cameroon. ...

Three groups of HIV-1 have been identified on the basis of differences in env: M, N, and O.^[67] Group M is the most prevalent and is subdivided into eight subtypes (or clades), based on the whole genome, which are geographically distinct.^[68] The most prevalent are subtypes B (found mainly in North America and Europe), A and D (found mainly in Africa), and C (found mainly in Africa and Asia); these subtypes form branches in the phylogenetic tree representing the lineage of the M group of HIV-1. Coinfection with distinct subtypes gives rise to circulating recombinant forms (CRFs). In 2000, the last year in which an analysis of global subtype prevalence was made, 47.2% of infections worldwide were of subtype C, 26.7% were of subtype A/CRF02_AG, 12.3% were of subtype B, 5.3% were of subtype D, 3.2% were of CRF_AE, and the remaining 5.3% were composed of other subtypes and CRFs.^[69] Most HIV-1 research is focused on subtype B; few laboratories focus on the other subtypes.^[70]

The genetic sequence of HIV-2 is only partially homologous to HIV-1 and more closely resembles that of SIV than HIV-1.

The clinical course of infection

For more details on this topic, see AIDS Diagnosis, AIDS Symptoms and Complications and WHO Disease Staging System for HIV Infection and Disease

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.

CD4+ T cell count (cells per µL)

HIV RNA copies per mL of plasma

Infection with HIV-1 is associated with a progressive decrease of the CD4⁺ T cell count and an increase in viral load. The stage of infection can be determined by measuring the patient's CD4⁺ T cell count, and the level of HIV in the blood. Acquired immune deficiency syndrome or acquired immunodeficiency syndrome (AIDS or Aids) is a collection of symptoms and infections resulting from the specific damage to the immune system caused by the human immunodeficiency virus (HIV). ... Acquired immune deficiency syndrome or acquired immunodeficiency syndrome (AIDS or Aids) is a collection of symptoms and infections resulting from the specific damage to the immune system caused by the human immunodeficiency virus (HIV). ... WHO Disease Staging System for HIV Infection and Disease are produced by the World Health Organisation. ... Graph showing HIV copies and CD4 counts over course of HIV infection File links The following pages link to this file: HIV Categories: GFDL images ... Graph showing HIV copies and CD4 counts over course of HIV infection File links The following pages link to this file: HIV Categories: GFDL images ... Viral load is a measure of the severity of a viral infection, and can be estimated by calculating the amount of virus in an involved body fluid, e. ...

The initial infection with HIV generally occurs after transfer of body fluids from an infected person to an uninfected one. The first stage of infection, the primary, or acute infection, is a period of rapid viral replication that immediately follows the individual's exposure to HIV leading to an abundance of virus in the peripheral blood with levels of HIV commonly approaching several million viruses per mL.^[71] This response is accompanied by a marked drop in the numbers of circulating CD4⁺ T cells. This acute viremia is associated in virtually all patients with the activation of CD8⁺ T cells, which kill HIV-infected cells, and subsequently with antibody production, or seroconversion. The CD8⁺ T cell response is thought to be important in controlling virus levels, which peak and then decline, as the CD4⁺ T cell counts rebound to around 800 cells per mL (the normal value is 1200 cells per mL ). A good CD8⁺ T cell response has been linked to slower disease progression and a better prognosis, though it does not eliminate the virus.^[72] During this period most individuals (80 to 90%) develop an influenza-like illness with symptoms of fever, malaise, lymphadenopathy, pharyngitis, headache, myalgia, and sometimes a rash.^[73] Because of the nonspecific nature of these illnesses, it is often not recognized as a sign of HIV infection. Even if patients go to their doctors or a hospital, they will often be misdiagnosed as having one of the more common infectious diseases with the same symptoms. Consequently, these primary symptoms are not used to diagnose HIV infection as they do not develop in all cases and because many are caused by other more common diseases. However, recognizing the syndrome can be important because the patient is much more infectious during this period. A cytotoxic (or TC) T cell is a T cell (a type of white blood cell) which has on its surface antigen receptors called T-cell receptors (TCRs) that can bind to fragments of antigens displayed by the Class I MHC molecules of virus (or other intracellular pathogen) infected somatic... Seroconversion is the development of detectable specific antibodies to microorganisms in the serum as a result of infection or immunization. ... An analogue medical thermometer showing the temperature of 38. ... Malaise is a term used to refer to a general state of discomfort, tiredness, or illness. ... Lymphadenopathy is swelling of one or more lymph nodes. ... Pharyngitis is a painful inflammation of the pharynx, and is colloquially referred to as a sore throat. ... A headache (medically known as cephalalgia, sometimes spelled as cephalgia) is a condition of pain in the head; sometimes neck or upper back pain may also be interpreted as a headache. ... Myalgia means muscle pain and is a symptom of many diseases and disorders. ...

A strong immune defense reduces the number of viral particles in the blood stream, marking the start of the infection's clinical latency stage. Clinical latency can vary between two weeks and 20 years. During this early phase of infection, HIV is active within lymphoid organs, where large amounts of virus become trapped in the follicular dendritic cells (FDC) network.^[74] The surrounding tissues that are rich in CD4⁺ T cells may also become infected, and viral particles accumulate both in infected cells and as free virus. Individuals who are in this phase are still infectious. During this time, CD4⁺ CD45RO⁺ T cells carry most of the proviral load.^[75] Incubation period is the time elapsed between exposure to a pathogenic organism and when symptoms and signs are first apparent. ... The human lymphatic system The lymphatic system is a complex network of lymphoid organs, lymph nodes, lymph ducts, and lymph vessels that produce and transport lymph fluid from tissues to the circulatory system. ... Dendritic cells (DC) are immune cells and form part of the mammal immune system. ... A helper (or TH) T cell is a T cell (a type of white blood cell) which has on its surface antigen receptors that can bind to fragments of antigens displayed by the Class II MHC molecules found on professional antigen-presenting cells (APCs). ...

When CD4⁺ T cell numbers decline below a critical level, cell-mediated immunity is lost, and infections with a variety of opportunistic microbes appear. The first symptoms often include moderate and unexplained weight loss, recurring respiratory tract infections (such as sinusitis, bronchitis, otitis media, pharyngitis), and oral ulcerations. Common opportunistic infections and tumors, most of which are normally controlled by robust CD4⁺ T cell-mediated immunity then start to affect the patient. Typically, resistance is lost early on to oral Candida species and to Mycobacterium tuberculosis, which leads to an increased susceptibilty to oral candidiasis (thrush) and tuberculosis. Later, reactivation of latent herpes viruses causes patients to suffer from shingles from Epstein-Barr virus-induced B-cell lymphomas, and from Kaposi's sarcoma, a tumor of endothelial cells that occurs when HIV proteins such as Tat interact with Human Herpesvirus-8. Pneumonia caused by the fungus Pneumocystis jiroveci is common and often fatal. In the final stages of AIDS, infection with cytomegalovirus (another herpes virus) or Mycobacterium avium complex is more prominent. Not all patients with AIDS get all these infections or tumors, and there are other tumors and infections that are less prominent but still significant. Sinusitis is inflammation of the paranasal sinuses from either bacterial, fungal, viral, allergic or autoimmune issues. ... This article is not about asthma. ... Otitis media is an inflammation of the middle ear segment of the ear. ... Pharyngitis is a painful inflammation of the pharynx, and is colloquially referred to as a sore throat. ... Oral candidiasis, also oral thrush, is an infection of yeast fungus, Candida albicans, (or, less commonly, Candida glabrata or Candida tropicalis) in the mucous membranes of the mouth. ... Tuberculosis (abbreviated as TB for Tubercle Bacillus) is a common and deadly infectious disease caused by the bacterium Mycobacterium tuberculosis, which most commonly affects the lungs (pulmonary TB) but can also affect the central nervous system, lymphatic system, circulatory system, genitourinary system, bones and joints. ... Genera Subfamily Alphaherpesvirinae    Simplexvirus    Varicellovirus    Mardivirus    Iltovirus Subfamily Betaherpesvirinae    Cytomegalovirus    Muromegalovirus    Roseolovirus Subfamily Gammaherpesvirinae    Lymphocryptovirus    Rhadinovirus Unassigned    Ictalurivirus The Herpesviridae are a family of DNA viruses that cause diseases in humans and animals. ... Herpes zoster, colloquially known as shingles, is the reactivation of varicella zoster virus, leading to a crop of painful blisters over the area of a dermatome. ... The Epstein-Barr virus (EBV), also called Human herpesvirus 4 (HHV-4), is a virus of the herpes family (which includes Herpes simplex virus and Cytomegalovirus), and is one of the most common viruses in humans. ... Tumor (American English) or tumour (British English) originally means swelling, and is sometimes still used with that meaning. ... The endothelium is the layer of thin, flat cells that lines the interior surface of blood vessels, forming an interface between circulating blood in the lumen and the rest of the vessel wall. ... Kaposis sarcoma-associated herpesvirus (KSHV) is the eighth human herpesvirus; its formal name according to the International Committee on Taxonomy of Viruses is HHV-8. ... Binomial name Pneumocystis jiroveci J.K.Frenkel Pneumocystis jiroveci, sometimes called by its former name Pneumocystis carinii, is a fungus (earlier classified as a protozoa) that causes pneumocystis jiroveci pneumonia (PCP). ... Species see text Cytomegalovirus (CMV), is a genus of Herpes viruses; in humans the species is known as Human herpesvirus 5 (HHV-5). ... Mycobacterium avium complex refers to infection by two species of bacteria, Mycobacterium avium and Mycobacterium intracellulare. ...

HIV test

Main article: HIV test

Many people are unaware that they are infected with HIV.^[76] For example, less than 1% of the sexually active urban population in Africa have been tested and this proportion is even lower in rural populations.^[76] Furthermore, only 0.5% of pregnant women attending urban health facilities are counselled, tested or receive their test results.^[76] Again, this proportion is even lower in rural health facilities.^[76] Since donors may therefore be unaware of their infection, donor blood and blood products used in medicine and medical research are routinely screened for HIV.^[77] Randal Tobias, U.S. Global AIDS Coordinator, being publicly tested for HIV/AIDS in Ethiopia in an effort to reduce the stigma of being tested. ...

HIV-1 testing consists of initial screening with an enzyme-linked immunosorbent assay (ELISA) to detect antibodies to HIV-1. Specimens with a nonreactive result from the initial ELISA are considered HIV-negative unless new exposure to an infected partner or partner of unknown HIV status has occurred. Specimens with a reactive ELISA result are retested in duplicate.^[78] If the result of either duplicate test is reactive, the specimen is reported as repeatedly reactive and undergoes confirmatory testing with a more specific supplemental test (e.g., Western blot or, less commonly, an immunofluorescence assay (IFA)). Only specimens that are repeatedly reactive by ELISA and positive by IFA or reactive by Western blot are considered HIV-positive and indicative of HIV infection. Specimens that are repeatedly ELISA-reactive occasionally provide an indeterminate Western blot result, which may be either an incomplete antibody response to HIV in an infected person, or nonspecific reactions in an uninfected person.^[79] Although IFA can be used to confirm infection in these ambiguous cases, this assay is not widely used. Generally, a second specimen should be collected more than a month later and retested for persons with indeterminate Western blot results. Although much less commonly available, nucleic acid testing (e.g., viral RNA or proviral DNA amplification method) can also help diagnosis in certain situations.^[78] In addition, a few tested specimens might provide inconclusive results because of a low quantity specimen. In these situations, a second specimen is collected and tested for HIV infection. The Enzyme-Linked Immunosorbent Assay (ELISA or EIA for short) is a biochemical technique used in immunology to detect the presence of an antibody or an antigen in a sample. ... Picture of a western blot with 5 vertical lanes A western blot (a. ...

Treatment

Abacavir - a nucleoside analog reverse transcriptase inhibitors (NARTIs or NRTIs)

The chemical structure of Abacavir

There is currently no vaccine or cure for HIV or AIDS. The only known method of prevention is avoiding exposure to the virus. However, an antiretroviral treatment, known as post-exposure prophylaxis is believed to reduce the risk of infection if begun directly after exposure.^[80] Current treatment for HIV infection consists of highly active antiretroviral therapy, or HAART.^[81] This has been highly beneficial to many HIV-infected individuals since its introduction in 1996, when the protease inhibitor-based HAART initially became available.^[82] Current HAART options are combinations (or "cocktails") consisting of at least three drugs belonging to at least two types, or "classes," of anti-retroviral agents. Typically, these classes are two nucleoside analogue reverse transcriptase inhibitors (NARTIs or NRTIs) plus either a protease inhibitor or a non-nucleoside reverse transcriptase inhibitor (NNRTI). Because AIDS progression in children is more rapid and less predictable than in adults, particularly in young infants, more aggressive treatment is recommended for children than adults.^[83] In developed countries where HAART is available, doctors assess their patients thoroughly: measuring the viral load, how fast CD4 declines, and patient readiness. They then decide when to recommend starting treatment.^[84] Image File history File linksMetadata Download high resolution version (1074x1074, 263 KB) Summary Ziagen (Abacavir) Licensing File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Abacavir AIDS Metadata This file contains additional information, probably added from the digital camera... Image File history File linksMetadata Download high resolution version (1074x1074, 263 KB) Summary Ziagen (Abacavir) Licensing File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Abacavir AIDS Metadata This file contains additional information, probably added from the digital camera... Abacavir (ABC) is extremely potent reverse transcriptase inhibitor, meant for the treatment of AIDS. ABC is capable of crossing the blood-brain barrier. ... Image File history File links Abacavir. ... Image File history File links Abacavir. ... An HIV vaccine is a hypothetical vaccine against HIV, the etiological agent of AIDS. As there is no known cure for AIDS, the search for a vaccine has become part of the struggle against the disease. ... Post-exposure prophylaxis (PEP) is any prophylactic treatment started immediately after exposure to a disease (such as a disease-causing virus), in order to prevent the disease from breaking out. ... The term antiretroviral drugs is used to describe drugs used against HIV infection (HIV is an RNA retrovirus). ... The term antiretroviral drugs is used to describe drugs used against HIV infection (HIV is an RNA retrovirus). ... Reverse transcriptase inhibitors (RTIs) are a class of antiretroviral drug used to treat HIV infection. ... Protease inhibitors are a class of medication used to treat or prevent viral infections. ... Antiretroviral drugs are medications for the treatment of infection by retroviruses, primarily HIV. Different classes of antiretroviral drugs act at different stages of the HIV life cycle. ... Viral load is a measure of the severity of a viral infection, and can be estimated by calculating the amount of virus in an involved body fluid, e. ...

HAART allows the stabilisation of the patient’s symptoms and viremia, but it neither cures the patient, nor alleviates the symptoms, and high levels of HIV-1, often HAART resistant, return once treatment is stopped.^[85][86] Moreover, it would take more than a lifetime for HIV infection to be cleared using HAART.^[87] Despite this, many HIV-infected individuals have experienced remarkable improvements in their general health and quality of life, which has led to a large reduction in HIV-associated morbidity and mortality in the developed world.^[82][88][89] A computer based study in 2006 projected that following the 2004 United States treatment guidelines gave an average life expectancy of an HIV infected individual to be 32.1 years from the time of infection if treatment was started when the CD4 count was 350/µL.^[90] This study was limited as it did not take into account possible future treatments and the projection has not been confirmed within a clinical cohort setting. In the absence of HAART, progression from HIV infection to AIDS has been observed to occur at a median of between nine to ten years and the median survival time after developing AIDS is only 9.2 months.^[91] However, HAART sometimes achieves far less than optimal results, in some circumstances being effective in less than fifty percent of patients. This is due to a variety of reasons such as medication intolerance/side effects, prior ineffective antiretroviral therapy and infection with a drug-resistant strain of HIV. However, non-adherence and non-persistence with antiretroviral therapy is the major reason most individuals fail to benefit from HAART.^[92] The reasons for non-adherence and non-persistence with HAART are varied and overlapping. Major psychosocial issues, such as poor access to medical care, inadequate social supports, psychiatric disease and drug abuse contribute to non-adherence. The complexity of these HAART regimens, whether due to pill number, dosing frequency, meal restrictions or other issues along with side effects that create intentional non-adherence also contribute to this problem.^[93][94][95] The side effects include lipodystrophy, dyslipidaemia, insulin resistance, an increase in cardiovascular risks and birth defects.^[96][97] In medicine, epidemiology and actuarial science, the term morbidity can refer to the state of being diseased (from Latin morbidus: sick, unhealthy), the degree or severity of a disease, the prevalence of a disease: the total number of cases in a particular population at a particular point in time, the... In probability theory and statistics, a median is a number dividing the higher half of a sample, a population, or a probability distribution from the lower half. ... In medicine, lipodystrophy is a condition characterized by abnormal or degernative conditions of the bodys fat tissue. ... Hypercholesterolemia (literally: high blood cholesterol) is the presence of high levels of cholesterol in the blood. ... Insulin resistance is the condition in which normal amounts of insulin are inadequate to produce a normal insulin response from fat, muscle and liver cells. ... The circulatory system or cardiovascular system is the organ system which circulates blood around the body of most animals. ... A congenital disorder is a medical condition or defect that is present at or before birth (for example, congenital heart disease). ...

The timing for starting HIV treatment is still debated. There is no question that treatment should be started before the patient's CD4 count falls below 200, and most national guidelines say to start treatment once the CD4 count falls below 350; but there is some evidence from cohort studies that treatment should be started before the CD4 count falls below 350.^[98][88] There is also evidence to say that treatment should be started before CD4 percentage falls below 15%.^[99] In those countries where CD4 counts are not available, patients with WHO stage III or IV disease^[100] should be offered treatment.

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.^[101] 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. Unfortunately, only a vaccine is thought to be able to halt the pandemic. This is because a vaccine would cost less, thus being affordable for developing countries, and would not require daily treatment.^[101] However, after over 20 years of research, HIV-1 remains a difficult target for a vaccine.^[101]

Epidemiology

Main article: AIDS pandemic

Prevalence of HIV among adults per country at the end of 2005 ██ 15–50% ██ 5–15% ██ 1–5% ██ 0.5–1.0% ██ 0.1–0.5% ██ <0.1% ██ no data

UNAIDS and the WHO estimate that AIDS has killed more than 25 million people since it was first recognized in 1981, making it one of the most destructive pandemics in recorded history. Despite recent, improved access to antiretroviral treatment and care in many regions of the world, the AIDS pandemic claimed an estimated 2.8 million (between 2.4 and 3.3 million) lives in 2005 of which more than half a million (570,000) were children.^[3] Acquired Immune Deficiency Syndrome (AIDS) has killed more than 25 million people since it was first recognized in 1981, making it one of the most destructive epidemics in recorded history. ... Image File history File links Download high-resolution version (1357x628, 32 KB) I modifyed GrCampbells exsisting Wikipeadia H.I.V. map of the same name (less the x2 at the end of it). ... Image File history File links Download high-resolution version (1357x628, 32 KB) I modifyed GrCampbells exsisting Wikipeadia H.I.V. map of the same name (less the x2 at the end of it). ...

Globally, between 33.4 and 46 million people currently live with HIV.^[3] In 2005, between 3.4 and 6.2 million people were newly infected and between 2.4 and 3.3 million people with AIDS died, an increase from 2004 and the highest number since 1981.

Sub-Saharan Africa remains by far the worst-affected region, with an estimated 21.6 to 27.4 million people currently living with HIV. Two million [1.5–3.0 million] of them are children younger than 15 years of age. More than 64% of all people living with HIV are in sub-Saharan Africa, as are more than three quarters of all women living with HIV. In 2005, there were 12.0 million [10.6–13.6 million] AIDS orphans living in sub-Saharan Africa 2005.^[3] South & South East Asia are second-worst affected with 15% of the total. AIDS accounts for the deaths of 500,000 children in this region. Two-thirds of HIV/AIDS infections in Asia occur in India, with an estimated 5.7 million infections (estimated 3.4–9.4 million) (0.9% of population), surpassing South Africa's estimated 5.5 million (4.9–6.1 million) (11.9% of population) infections, making India the country with the highest number of HIV infections in the world.^[102] In the 35 African nations with the highest prevalence, average life expectancy is 48.3 years—6.5 years less than it would be without the disease.^[103] Acquired Immune Deficiency Syndrome (AIDS) has killed more than 25 million people since it was first recognized in 1981, making it one of the most destructive epidemics in recorded history. ... Acquired Immune Deficiency Syndrome (AIDS) has killed more than 25 million people since it was first recognized in 1981, making it one of the most destructive epidemics in recorded history. ... World map showing the location of Asia. ... World map of life expectancy Life expectancy is a statistical measure defined as the expected (mean) survival of human beings based upon a number of criteria such as gender and geographic location. ...

The latest evaluation report of the World Bank's Operations Evaluation Department assesses the development effectiveness of the World Bank's country-level HIV/AIDS assistance defined as policy dialogue, analytic work, and lending with the explicit objective of reducing the scope or impact of the AIDS epidemic.^[104] This is the first comprehensive evaluation of the World Bank's HIV/AIDS support to countries, from the beginning of the epidemic through mid-2004. Because the Bank aims to assist in implementation of national government programmes, their experience provides important insights on how national AIDS programmes can be made more effective. The World Bank Group is a group of five international organizations responsible for providing finance and advice to countries for the purposes of economic development and poverty. ...

The development of HAART as effective therapy for HIV infection and AIDS has substantially reduced the death rate from this disease in those areas where these drugs are widely available. This has created the misperception that the disease has gone away. In fact, as the life expectancy of persons with AIDS has increased in countries where HAART is widely used, the number of persons living with AIDS has increased substantially. In the United States, the number of persons with AIDS increased from about 35,000 in 1988 to over 220,000 in 1996.^[105] The term antiretroviral drugs is used to describe drugs used against HIV infection (HIV is an RNA retrovirus). ...

In Africa, the number of MTCT and the prevalence of AIDS is beginning to reverse decades of steady progress in child survival. Countries such as Uganda are attempting to curb the MTCT epidemic by offering VCT (voluntary counselling and testing), PMTCT (prevention of mother-to-child transmission) and ANC (ante-natal care) services, which include the distribution of antiretroviral therapy.

Alternative hypotheses

Main article: AIDS reappraisal

A small minority of scientists and activists question the connection between HIV and AIDS,^[106] the existence of HIV itself,^[107] or the validity of current testing methods. These claims are considered unsupported by most of the scientific community, who accuse the dissenters of selectively ignoring evidence in favor of HIV's role in AIDS and irresponsibly posing a threat to public health by discouraging HIV testing and proven treatments.^[108][109] The AIDS reappraisal movement (or AIDS dissident movement) is a loosely connected group of activists — journalists, scientists, HIV-positive persons, and concerned citizens — who dispute the scientific consensus that the human immunodeficiency virus (HIV) is the cause of acquired immune deficiency syndrome (AIDS). ... Public health is concerned with threats to the overall health of a community based on population health analysis. ...

AIDS dissidents assert that the current mainstream approach to AIDS, based on HIV causation, has resulted in inaccurate diagnoses, psychological terror, toxic treatments, and a squandering of public funds.^[110] Dissident views have been widely rejected,^[111][112] and are considered pseudoscience by the mainstream scientific community. Phrenology is regarded today as a classic example of pseudoscience. ...

Proteins Involved in Treatment

• APOBEC3G

APOBEC3G is a human protein that interferes with the replication of HIV. It was first identified by Ann Sheehy in 2002 as a cellular factor able to restrict replication of HIV-1 lacking the viral accessory protein Vif. ...

Notes and references

2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... August 24 is the 236th day of the year in the Gregorian Calendar (237th in leap years), with 129 days remaining. ... The Joint United Nations Programme on HIV and AIDS, or UNAIDS, is the main advocate for accelerated, comprehensive and coordinated global action on the HIV epidemic. ... PDF is an abbreviation with several meanings: Portable Document Format Post-doctoral fellowship Probability density function There also is an electronic design automation company named PDF Solutions. ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... June 8 is the 159th day of the year in the Gregorian Calendar (160th in leap years), with 206 days remaining. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... The Joint United Nations Programme on HIV and AIDS, or UNAIDS, is the main advocate for accelerated, comprehensive and coordinated global action on the HIV epidemic. ... PDF is an abbreviation with several meanings: Portable Document Format Post-doctoral fellowship Probability density function There also is an electronic design automation company named PDF Solutions. ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... February 28 is the 59th day of the year in the Gregorian calendar. ... CDC is an abbreviation which can mean any of the following: Centers for Disease Control and Prevention Community of Democratic Choice, a group of nine Eastern-European states Change data capture, in data warehousing Clock Domain Crossing, or simply clock-crossing in computing. ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... January 17 is the 17th day of the year in the Gregorian calendar. ... This page is a candidate to be copied to Wikisource. ... The National Institutes of Health (NIH) is the primary agency of the United States government responsible for medical research. ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... February 28 is the 59th day of the year in the Gregorian calendar. ... This page is a candidate to be copied to Wikisource. ... The National Institutes of Health (NIH) is the primary agency of the United States government responsible for medical research. ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... February 28 is the 59th day of the year in the Gregorian calendar. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... May 25 is the 145th day of the year in the Gregorian calendar (146th in leap years). ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... 1987 (MCMLXXXVII) was a common year starting on Thursday of the Gregorian calendar. ... October 28 is the 301st day of the year (302nd in leap years) in the Gregorian Calendar, with 64 days remaining. ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... June 19 is the 170th day of the year (171st in leap years) in the Gregorian Calendar, with 195 days remaining. ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... October 23 is the 296th day of the year (297th in leap years) in the Gregorian calendar. ... Who can refer to: WHO, World Health Organization The Who, a British rock band The Guess Who, a Canadian rock band who (pronoun), an English language interrogative pronoun. ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... March 28 is the 87th day of the year in the Gregorian Calendar (88th in leap years). ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... March 28 is the 87th day of the year in the Gregorian Calendar (88th in leap years). ... PDF is an abbreviation with several meanings: Portable Document Format Post-doctoral fellowship Probability density function There also is an electronic design automation company named PDF Solutions. ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... September 1 is the 244th day of the year (245th in leap years) in the Gregorian calendar. ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... September 14 is the 257th day of the year in the Gregorian calendar (258th in leap years). ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... PDF is an abbreviation with several meanings: Portable Document Format Post-doctoral fellowship Probability density function There also is an electronic design automation company named PDF Solutions. ... Los Alamos is an unincorporated townsite in Los Alamos County, New Mexico. ... Los Alamos National Laboratory, aerial view from 1995. ... PDF is an abbreviation with several meanings: Portable Document Format Post-doctoral fellowship Probability density function There also is an electronic design automation company named PDF Solutions. ... Los Alamos is an unincorporated townsite in Los Alamos County, New Mexico. ... Los Alamos National Laboratory, aerial view from 1995. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... September 1 is the 244th day of the year (245th in leap years) in the Gregorian calendar. ... Nickname: City on the Hill, Beantown, The Hub (of the Universe)1 Location in Massachusetts, USA Counties Suffolk County Mayor Thomas M. Menino (D) Area    - City 232. ... The United States Department of Health and Human Services, often abbreviated HHS, is a Cabinet department of the United States government with the goal of protecting the health of all Americans and providing essential human services. ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... January 17 is the 17th day of the year in the Gregorian calendar. ... The United States Department of Health and Human Services, often abbreviated HHS, is a Cabinet department of the United States government with the goal of protecting the health of all Americans and providing essential human services. ... November 3 is the 307th day of the year (308th in leap years) in the Gregorian Calendar, with 58 days remaining. ... 2005 (MMV) was a common year starting on Saturday of the Gregorian calendar. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... January 17 is the 17th day of the year in the Gregorian calendar. ... The United States Department of Health and Human Services, often abbreviated HHS, is a Cabinet department of the United States government with the goal of protecting the health of all Americans and providing essential human services. ... October 6 is the 279th day of the year (280th in leap years). ... 2005 (MMV) was a common year starting on Saturday of the Gregorian calendar. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... January 17 is the 17th day of the year in the Gregorian calendar. ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... December 27 is the 361st day of the year in the Gregorian Calendar (362nd in leap years). ... The Joint United Nations Programme on HIV and AIDS, or UNAIDS, is the main advocate for accelerated, comprehensive and coordinated global action on the HIV epidemic. ... PDF is an abbreviation with several meanings: Portable Document Format Post-doctoral fellowship Probability density function There also is an electronic design automation company named PDF Solutions. ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... June 8 is the 159th day of the year in the Gregorian Calendar (160th in leap years), with 206 days remaining. ... PDF is an abbreviation with several meanings: Portable Document Format Post-doctoral fellowship Probability density function There also is an electronic design automation company named PDF Solutions. ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... June 15 is the 166th day of the year in the Gregorian calendar (167th in leap years), with 199 days remaining. ... The World Bank Group is a group of five international organizations responsible for providing finance and advice to countries for the purposes of economic development and poverty. ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... January 17 is the 17th day of the year in the Gregorian calendar. ... The Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia, is recognized as the leading United States agency for protecting the public health and safety of people. ... PDF is an abbreviation with several meanings: Portable Document Format Post-doctoral fellowship Probability density function There also is an electronic design automation company named PDF Solutions. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... August 13 is the 225th day of the year in the Gregorian Calendar (226th in leap years), with 140 days remaining. ... PDF is an abbreviation with several meanings: Portable Document Format Post-doctoral fellowship Probability density function There also is an electronic design automation company named PDF Solutions. ... The Henry J. Kaiser Family Foundation (KFF), or just Kaiser Family Foundation, is a U.S.-based non-profit philanthropic private operating foundation headquartered in Menlo Park, California. ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... December 7 is the 341st day (342nd in leap years) of the year in the Gregorian calendar. ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... June 19 is the 170th day of the year (171st in leap years) in the Gregorian Calendar, with 195 days remaining. ... National Institute of Allergy and Infectious Diseases (NIAID) is a component of the National Institutes of Health (NIH), which is an agency of the United States Department of Health and Human Services. ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... September 7 is the 250th day of the year (251st in leap years). ... Acquired immune deficiency syndrome or acquired immunodeficiency syndrome (AIDS or Aids) is a collection of symptoms and infections resulting from the specific damage to the immune system caused by the human immunodeficiency virus (HIV). ... The genome and proteins of HIV have been the subject of extensive research in the twenty years since the discovery of the virus. ... Randal Tobias, U.S. Global AIDS Coordinator, being publicly tested for HIV/AIDS in Ethiopia in an effort to reduce the stigma of being tested. ... This classification system is how the United States agency, the Centers for Disease Control and Prevention (CDC) classifies HIV disease and infection. ... This article needs to be cleaned up to conform to a higher standard of quality. ... An HIV vaccine is a hypothetical vaccine against HIV, the etiological agent of AIDS. As there is no known cure for AIDS, the search for a vaccine has become part of the struggle against the disease. ... WHO Disease Staging System for HIV Infection and Disease are produced by the World Health Organisation. ... AIDS dementia complex (ADC; also known as HIV dementia, HIV encephalopathy and HIV-associated dementia) has become a common neurological disorder associated with HIV infection and AIDS. It is is a metabolic encephalopathy induced by HIV infection and fueled by immune activation of brain macrophages and microglia. ... Antiretroviral drugs are medications for the treatment of infection by retroviruses, primarily HIV. Different classes of antiretroviral drugs act at different stages of the HIV life cycle. ... Scanning electron micrograph of HIV-1 budding from cultured lymphocyte. ... Acquired Immune Deficiency Syndrome (AIDS) has killed more than 25 million people since it was first recognized in 1981, making it one of the most destructive epidemics in recorded history. ... A United States HIV/AIDS Memorial Museum, to be located in Newark, New Jersey, is being planned for opening in 2006. ... This is a timeline of AIDS. 1959 The first known case of HIV in a human was found in a person who died in the Congo (Zhu et al. ... According to the oral polio vaccine (OPV) AIDS hypothesis, the AIDS pandemic originated from live polio vaccines prepared in chimpanzee tissue cultures (at least some of which were almost certainly contaminated with chimpanzee SIV) which were administered to up to one million Africans between 1957 and 1960. ... The AIDS reappraisal movement (or AIDS dissident movement) is a loosely connected group of activists — journalists, scientists, HIV-positive persons, and concerned citizens — who dispute the scientific consensus that the human immunodeficiency virus (HIV) is the cause of acquired immune deficiency syndrome (AIDS). ... The Duesberg hypothesis is the claim, initially put forward by Peter Duesberg, that various non-infectious factors including recreational and pharmaceutical drug use are the cause of AIDS, and that HIV (human immunodeficiency virus) is a harmless passenger virus. ... The International AIDS Society is the custodian of the International AIDS Conferences, the paramount gathering of all disciplines in HIV/AIDS now held every two years. ... The International AIDS Society (IAS) is the worlds professional society for scientists, health care and public health workers, and others engaged in HIV/AIDS prevention, control and care. ... The Red Ribbon is the global symbol for solidarity with HIV-positive people and those living with AIDS. World AIDS Day, observed December 1 each year, is dedicated to raising awareness of the global AIDS pandemic caused by the spread of HIV infection. ... The Treatment Action Campaign is a South African grassroots pressure group which was founded by Zackie Achmat, an HIV-positive activist who refused anti-retroviral treatment (ARVs) until they were universally available. ... The Joint United Nations Programme on HIV and AIDS, or UNAIDS, is the main advocate for accelerated, comprehensive and coordinated global action on the HIV epidemic. ... The AIDS Quilt The AIDS Memorial Quilt is an enormous quilt made as a memorial to and celebration of the lives of people who have died of AIDS-related causes. ... Because the worldwide spread of AIDS has had such a great effect on millions of people worldwide, a number of misconceptions have arisen surrounding the disease. ... Television star Pedro Zamora did much to promote understanding of people living with HIV in the USA This is an incomplete list, which may never be able to satisfy certain standards for completeness. ... The People With AIDS (PWA) Self-Empowerment Movement was a movement of those diagnosed with AIDS and grew out of San Francisco. ... Acquired Immune Deficiency Syndrome (AIDS) has killed more than 25 million people since it was first recognized in 1981, making it one of the most destructive epidemics in recorded history. ... AIDS education at a school in Uganda. ... This article or section is in need of attention from an expert on the subject. ... This article or section is in need of attention from an expert on the subject. ... This article or section is in need of attention from an expert on the subject. ... This article or section is in need of attention from an expert on the subject. ... This article or section is in need of attention from an expert on the subject. ... // History In the early 1980s, doctors in Los Angeles, New York City, and San Francisco began seeing young men with Kaposis Sarcoma, a cancer usually associated with elderly men of Mediterranean ethnicity. ... This is a list of countries and territories by HIV/AIDS adult prevalence rate, based on The World Factbook, accessed in September 2005. ... (STDs) — also known as sexually transmissible diseases, sexually transmitted infections (STIs) or (infrequently) venereal diseases (VD) or social disease — are diseases or infections that have a significant probability of transmission between humans by means of sexual contact, vaginal intercourse, oral sex, and/or anal sex. ... Phyla Actinobacteria Aquificae Chlamydiae Bacteroidetes/Chlorobi Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Lentisphaerae Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Verrucomicrobia Bacteria (singular: bacterium) are unicellular microorganisms. ... Chancroid is a sexually transmitted disease characterized by painful sores on the genitalia. ... Binomial name Haemophilus ducreyi A chancroid is an STD characterized by painful sores on the genitalia. ... Chlamydia is a common term for infection with any bacteria belonging to the phylum Chlamydiae. ... Binomial name Chlamydia trachomatis Busacca, 1935 Chlamydia trachomatis is a species of the chlamydiae, a group of obligately intracellular bacteria. ... Granuloma inguinale or Donovanosis is a bacterial disease caused by the organism Calymmatobacterium granulomatis. ... Lymphogranuloma venereum (LGV), also known as lymphopathia venerea, tropical bubo, climatic bubo, strumous bubo, poradenitis inguinales, Durand-Nicolas-Favre disease and lymphogranuloma inguinale, is a sexually transmitted disease caused by the invasive serovars L1, L2, or L3 of Chlamydia trachomatis. ... Binomial name Chlamydia trachomatis Busacca, 1935 Chlamydia trachomatis is a species of the chlamydiae, a group of obligately intracellular bacteria. ... Gonorrhoea (gonorrhea in American English; formally acute gonococcal perihepatitis), is among the most common sexually-transmitted diseases in the world and is caused by Gram-negative bacterium Neisseria gonorrhoeae. ... Binomial name Neisseria gonorrhoeae Zopf, 1885 Neisseria gonorrhoeae is a species of Gram-negative (see also Gram Stain) bacteria responsible for the disease gonorrhoea. ... Syphilis is a sexually transmitted infection (STI) caused by a spirochaete bacterium, Treponema pallidum. ... Binomial name Treponema pallidum Schaudinn & Hoffmann, 1905 Treponema pallidum is a gram-negative spirochaete bacterium and is considered to be metabolically crippled. ... Binomial name Ureaplasma urealyticum Shepard et al. ... Wikisource has an original article from the 1911 Encyclopædia Britannica about: Protozoa Protozoa (in Greek proto = first and zoa = animals) are single-celled eukaryotes (organisms whose cells have nuclei) that commonly show characteristics usually associated with animals, most notably mobility and heterotrophy. ... Trichomoniasis, sometimes referred to as trich or the ping pong disease, is a common sexually transmitted disease that affects 2 to 3 million Americans yearly. ... Binomial name Trichomonas vaginalis (Donné 1836) Trichomonas vaginalis, an anaerobic, parasitic flagellated protozoan, is the causative agent of trichomoniasis, and is the most common pathogenic protozoan infection of humans in industrialized countries. ... Mites parasitising a harvestman Parasitism is one version of symbiosis (living together), a phenomenon in which two organisms which are phylogenetically unrelated co-exist over a prolonged period of time, usually their entire life. ... Crab lice (singular, louse), scientific name Phthirus pubis and commonly called crabs due to their resemblance to the crab, are one of three kinds of human lice in the large group of lice families, the others being head lice and body lice, which live in clothing. ... Groups I: dsDNA viruses II: ssDNA viruses III: dsRNA viruses IV: (+)ssRNA viruses V: (-)ssRNA viruses VI: ssRNA-RT viruses VII: dsDNA-RT viruses A virus (Latin, poison) is a microscopic particle that can infect the cells of a biological organism. ... Acquired immune deficiency syndrome or acquired immunodeficiency syndrome (AIDS or Aids) is a collection of symptoms and infections resulting from the specific damage to the immune system caused by the human immunodeficiency virus (HIV). ... Cervical cancer is a malignancy of the cervix. ... Genital warts (or condyloma, or condylomata acuminata) is a highly contagious sexually transmitted infection. ... The naked protein coat (capsid) of a papillomavirus HPV redirects here. ... Hepatitis B is a disease of the liver caused by the Hepatitis B virus (HBV), a member of the Hepadnavirus family[1] and one of several unrelated viral species which cause viral hepatitis. ... It has been suggested that this article or section be merged with Herpes simplex virus. ... This article is about the virus. ... Molluscum contagiosum are wart-like tumors of the skin caused by the molluscum contagiosum virus (MCV-1 to -4), a DNA poxvirus. ... Inflammation of the tissues of the cervix is known as cervicitis. ... Epididymitis is a medical condition in which the epididymis becomes inflamed. ... Infertility is the inability to naturally conceive a child or to carry a pregnancy to full term. ... Non-gonococcal urethritis (NGU) is an inflammation of the urethra which is not caused by gonorrheal infection. ... Pelvic inflammatory disease (or disorder) (PID) is a generic term for infection of the female uterus, fallopian tubes, and/or ovaries. ... Premature birth (also known as preterm birth) is defined medically as childbirth occurring earlier than 37 completed weeks of gestation. ... Proctitis (Noun) Inflammation of the rectum. ... Prostatitis is any form of inflammation of the prostate gland. ... Reactive arthritis is a condition with symptoms similar to arthritis or rheumatism. ... Urethritis is an inflammation of the urethra. ...

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