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 ...
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 ...
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 ...
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 ...
Marijuana rivals mainstream drugs for HIV/AIDS symptoms
May 29, 2009 |
5 / 5 (3) |
0
Those in the United States living with HIV/AIDS are more likely to use marijuana than those in Kenya, South Africa or Puerto Rica to alleviate their symptoms, according to a new study published in Clinical Nursing Research, publis ...
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 ...
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 ...
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 ...
A natural approach for HIV vaccine
Medicine & Health / HIV & AIDS
Mar 15, 2009 |
4 / 5 (1) |
0
(PhysOrg.com) -- For 25 years, researchers have tried and failed to develop an HIV vaccine, primarily by focusing on a small number of engineered "super antibodies" to fend off the virus before it takes hold. So far, these ...
AIDS: Microbicide gel 'highly encouraging' in lab tests
Medicine & Health / HIV & AIDS
Mar 04, 2009 |
4.5 / 5 (2) |
0
The dogged search for a vaginal gel to thwart the AIDS virus earned some good news on Wednesday as scientists announced that a cheap, commonly-used compound shielded monkeys from a lethal cousin of HIV.
Biological catch-22 prevents induction of antibodies that block HIV
Medicine & Health / HIV & AIDS
Dec 15, 2009 |
4.5 / 5 (2) |
2
Scientists seeking to understand how to make an AIDS vaccine have found the cause of a major roadblock. It turns out that the immune system can indeed produce cells with the potential to manufacture powerful HIV-blocking ...
Gene Hijacked By HIV Ancestor Suggests New Way to Block Viral Reproduction
Dec 07, 2009 |
4.9 / 5 (7) |
0
(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 ...
Why Some Monkeys Don't Get AIDS
Medicine & Health / HIV & AIDS
Dec 03, 2009 |
not rated yet |
0
(PhysOrg.com) -- Two studies published this month in the Journal of Clinical Investigation provide a significant advance in understanding how some species of monkeys such as sooty mangabeys and African green ...
Imaging study shows HIV particles assembling around its genome
Medicine & Health / HIV & AIDS
Nov 17, 2009 |
5 / 5 (1) |
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(PhysOrg.com) -- The genesis of one the planet's most lethal viruses, HIV, has been caught on tape. New imaging experiments show individual HIV genomes -- strands of RNA — docking on the inner membrane of an infected cell ...
