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.
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) |
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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 ...
Research reveals further progress toward AIDS vaccine
Medicine & Health / HIV & AIDS
Dec 14, 2009 |
3 / 5 (2) |
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(PHILADELPHIA) Researchers from Thomas Jefferson University are one step closer to developing a vaccine against the AIDS disease.
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 ...
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.
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.
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 ...
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 ...
UNL research aims to understand homelessness among women
Other Sciences / Social Sciences
Dec 23, 2009 |
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(PhysOrg.com) -- Women make up nearly one-third of the homeless population in the United States. Yet little is known about how they become homeless or how they live. University of Nebraska-Lincoln sociologist Les Whitbeck ...
Researchers creating model of HIV care for developing nations
Medicine & Health / HIV & AIDS
Dec 21, 2009 |
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(PhysOrg.com) -- Expanding Michigan State University's global health outreach, a team of researchers is working in the Dominican Republic to establish a model for HIV/AIDS care that can be exported to other resource-limited ...
Routine HIV screening in community health centers boosts HIV testing
Medicine & Health / HIV & AIDS
Dec 15, 2009 |
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UCSF researchers have that found routinely offering rapid HIV tests to patients in community health centers can significantly increase the number of patients screened for HIV.
New insight into selective binding properties of infectious HIV
Medicine & Health / HIV & AIDS
Dec 15, 2009 |
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Free infectious HIV-1 is widely thought to be the major form of the virus in the blood of infected persons. U.S. Military HIV Research Program (MHRP) researchers, however, have demonstrated that essentially all of the infectious ...
