Related topics: aids , hiv infection , vaccine , immune system , infectious diseases
HIV
hideHuman immunodeficiency virus (HIV) is a lentivirus (a member of the retrovirus family) that causes acquired immunodeficiency syndrome (AIDS), a condition in humans in which the immune system begins to fail, leading to life-threatening opportunistic infections. Infection with HIV occurs by the transfer of blood, semen, vaginal fluid, pre-ejaculate, or breast milk. Within these bodily fluids, HIV is present as both free virus particles and virus within infected immune cells. The four major routes of transmission are unsafe sex, contaminated needles, breast milk, and transmission from an infected mother to her baby at birth (Vertical transmission). Screening of blood products for HIV has largely eliminated transmission through blood transfusions or infected blood products in the developed world.
HIV infection in humans is now pandemic. From 1981 to 2006, AIDS killed more than 25 million people. HIV infects about 0.6 percent of the world's population. In 2005 alone, AIDS claimed an estimated 2.4–3.3 million lives, of which more than 570,000 were children. A third of these deaths are occurring in sub-Saharan Africa, retarding economic growth and increasing poverty. According to current estimates, HIV is set to infect 90 million people in Africa, resulting in a minimum estimate of 18 million orphans. Antiretroviral treatment reduces both the mortality and the morbidity of HIV infection, but routine access to antiretroviral medication is not available in all countries.
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.
Eventually most HIV-infected individuals develop AIDS. These individuals mostly die from opportunistic infections or malignancies associated with the progressive failure of the immune system. Without treatment, about 9 out of every 10 persons with HIV will progress to AIDS after 10–15 years. Many progress much sooner. Treatment with anti-retrovirals increases the life expectancy of people infected with HIV. Even after HIV has progressed to diagnosable AIDS, the average survival time with antiretroviral therapy (as of 2005) is estimated to be more than 5 years. Without antiretroviral therapy, death normally occurs within a year.
For more information about HIV, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with hiv
Researchers demonstrate that stem cells can be engineered to kill HIV
Medicine & Health / HIV & AIDS
Dec 08, 2009 |
4.9 / 5 (18) |
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(PhysOrg.com) -- UCLA AIDS Institute researchers have for the first time demonstrated that human blood stem cells can be engineered to target and kill HIV-infected cells.
A world first: Vaccine helps prevent HIV infection
Medicine & Health / HIV & AIDS
Sep 24, 2009 |
4.3 / 5 (10) |
7
(PhysOrg.com) -- In an encouraging development, an investigational vaccine regimen has been shown to be well-tolerated and to have a modest effect in preventing HIV infection in a clinical trial involving ...
Scientists show why anti-HIV antibodies are ineffective at blocking infection
Medicine & Health / HIV & AIDS
Apr 22, 2009 |
5 / 5 (8) |
2
Some 25 years after the AIDS epidemic spawned a worldwide search for an effective vaccine against the human immunodeficiency virus (HIV), progress in the field seems to have effectively become stalled. The ...
Researchers decode structure of an entire HIV genome
Medicine & Health / HIV & AIDS
Aug 05, 2009 |
5 / 5 (8) |
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The structure of an entire HIV genome has been decoded for the first time by researchers at the University of North Carolina at Chapel Hill. The results have widespread implications for understanding the strategies ...
Redefining DNA: Darwin from the atom up
Mar 23, 2009 |
3.9 / 5 (10) |
1
In a dramatic rewrite of the recipe for life, scientists from Florida today described the design of a new type of DNA with 12 chemical letters instead of the usual four. Presented here at the 237th National Meeting of the ...
Gates Foundation's Grand Challenges Explorations Rewards Bold Ideas
May 06, 2009 |
4.5 / 5 (8) |
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Even in troubled times, The Bill and Melinda Gates Foundation recognize innovation for the betterment of mankind takes money. The Gates Foundation is providing $100,000 to 81 cutting edge health researcher ...
Gene Hijacked By HIV Ancestor Suggests New Way to Block Viral Reproduction
Dec 07, 2009 |
4.9 / 5 (7) |
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(PhysOrg.com) -- An ancestor of the AIDS virus hijacked an entire gene, perhaps from some prehistoric cat it had infected, a gene that makes it much better able to infect humans, according to a study published ...
Researchers uncover approach for possibly eradicating HIV infection
Medicine & Health / HIV & AIDS
Jun 21, 2009 |
4.6 / 5 (7) |
0
Researchers from the newly-established VGTI Florida and the University of Montreal have uncovered a possible method for eradicating HIV infection in the human body. The researchers have also revealed new information which ...
Novel vaccine approach offers hope in fight against HIV
Medicine & Health / HIV & AIDS
May 17, 2009 |
3.9 / 5 (7) |
3
A research team may have broken the stubborn impasse that has frustrated the invention of an effective HIV vaccine, by using an approach that bypasses the usual path followed by vaccine developers. By using ...
New contraceptive device is designed to prevent sexual transmission of HIV
Medicine & Health / HIV & AIDS
May 19, 2009 |
4.2 / 5 (6) |
2
Researchers from Weill Cornell Medical College have published results showing that a new contraceptive device may also effectively block the transmission of the HIV virus. Findings show that the device prevents infection ...
New model of female condom could bring wider use
Medicine & Health / HIV & AIDS
Apr 16, 2009 |
4.2 / 5 (5) |
0
(AP) -- Advocates of the female condom are promoting a less costly, more user-friendly version that they hope will vastly expand its role in the global fight against AIDS and other sexually transmitted diseases.
New study reveals structure of the HIV protein shell
Jun 12, 2009 |
5 / 5 (4) |
1
New research by scientists at The Scripps Research Institute and other institutions provides a close-up look at the cone-shaped shell that is the hallmark of human immunodeficiency virus (HIV), revealing how ...
HIV's ancestors 'plagued first mammals'
Other Sciences / Archaeology & Fossils
Sep 18, 2009 |
4.5 / 5 (4) |
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(PhysOrg.com) -- The retroviruses which gave rise to HIV have been battling it out with mammal immune systems since mammals first evolved around 100 million years ago - about 85 million years earlier than ...
HIV: Male circumcision does not shield women
Medicine & Health / HIV & AIDS
Jul 17, 2009 |
3.6 / 5 (5) |
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Circumcision of men with HIV does not reduce the risk of infection for women, according to a study published on Friday by The Lancet.
Regulatory role of key molecule discovered
Sep 17, 2009 |
4.5 / 5 (4) |
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Discovery by Hebrew University of Jerusalem researchers of an additional role for a key molecule in our bodies provides a further step in world-wide efforts to develop genetic regulation aimed at controlling ...
