Related topics: virus , aids
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
Research reveals further progress toward AIDS vaccine
Medicine & Health / HIV & AIDS
19 hours ago |
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(PHILADELPHIA) Researchers from Thomas Jefferson University are one step closer to developing a vaccine against the AIDS disease.
Hindering HIV-1-fighting immune cells
Medicine & Health / HIV & AIDS
20 hours ago |
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Immune proteins called HLA molecules help to activate killer T cell responses against pathogens. But according to a study that will be published online on December 14th in the Journal of Experimental Medicine, one partic ...
Researchers demonstrate that stem cells can be engineered to kill HIV
Medicine & Health / HIV & AIDS
Dec 08, 2009 |
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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.
Gene Hijacked By HIV Ancestor Suggests New Way to Block Viral Reproduction
Dec 07, 2009 |
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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 ...
Why Some Monkeys Don't Get AIDS
Medicine & Health / HIV & AIDS
Dec 03, 2009 |
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(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 ...
HIV-related memory loss linked to Alzheimer's protein
Medicine & Health / Neuroscience
Dec 07, 2009 |
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More than half of HIV patients experience memory problems and other cognitive impairments as they age, and doctors know little about the underlying causes. New research from Washington University School of Medicine in St. ...
New study measures HIV anti-retroviral regimens' safety and efficacy
Medicine & Health / HIV & AIDS
Dec 01, 2009 |
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A study in the New England Journal of Medicine released on World AIDS Day reports that viral failure, the point at which medication can no longer suppress the HIV infection, was twice as likely and happen ...
Researchers identify new mechanism of blocking HIV-1 from entering cells
Medicine & Health / HIV & AIDS
Nov 30, 2009 |
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Publishing in PLoS Pathogens, researchers at from the Kimmel Cancer Center at Jefferson have found a novel mechanism by which drugs block HIV-1 from entering host cells.
Availability of vaccine no guarantee public will want it
Nov 30, 2009 |
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Just because a vaccine is available doesn't mean people will choose to be inoculated, according to new UofT research published amid widespread public confusion around the merit of H1N1 flu shots.
A reductionist approach to HIV research
Medicine & Health / HIV & AIDS
Nov 30, 2009 |
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A major obstacle to HIV research is the virus's exquisite specialisation for its human host - meaning that scientists' traditional tools, like the humble lab mouse, can deliver only limited information. Now, a team of researchers ...
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 ...
HIV vaccine failure probably caused by virus used, says new research
Medicine & Health / HIV & AIDS
Nov 16, 2009 |
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The recent failure of an HIV vaccine was probably caused by the immune system reacting to the virus 'shell' used to transmit the therapy around the body, according to research published today in the Proceedings of the Na ...
A world first: Vaccine helps prevent HIV infection
Medicine & Health / HIV & AIDS
Sep 24, 2009 |
4.3 / 5 (10) |
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(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 ...
Marijuana rivals mainstream drugs for HIV/AIDS symptoms
May 29, 2009 |
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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 ...
Tailor-made HIV/AIDS treatment closer to reality
Medicine & Health / HIV & AIDS
Nov 25, 2009 |
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An innovative treatment for HIV patients developed by McGill University Health Centre researchers has passed its first clinical trial with flying colours. The new approach is an immunotherapy customized for each individual ...
