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.
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News tagged with hiv virus
Scientists explain binding action of 2 key HIV antibodies; could lead to new vaccine design
Nov 09, 2009 |
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A very close and detailed study of how the most robust antibodies work to block the HIV virus as it seeks entry into healthy cells has revealed a new direction for researchers hoping to design an effective vaccine.
An HIV-blocking gel for women
Medicine & Health / HIV & AIDS
Aug 10, 2009 |
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University of Utah scientists developed a new kind of "molecular condom" to protect women from AIDS in Africa and other impoverished areas. Before sex, women would insert a vaginal gel that turns semisolid ...
MicroRNAs help control HIV life cycle
Jun 25, 2009 |
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Scientists at Burnham Institute for Medical Research (Burnham) have discovered that specific microRNAs (non-coding RNAs that interfere with gene expression) reduce HIV replication and infectivity in human T-cells. In particular, ...
Researchers develop game for HIV+ youth
Medicine & Health / HIV & AIDS
Jun 23, 2009 |
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Researchers at The University of Texas School of Public Health have developed a game for HIV-positive youth, +CLICK, designed to reduce secondary transmission of the virus.
Researchers uncover approach for possibly eradicating HIV infection
Medicine & Health / HIV & AIDS
Jun 21, 2009 |
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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 ...
HIV's march around Europe mapped
Medicine & Health / HIV & AIDS
May 20, 2009 |
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Those travelling abroad should take seriously advice to pack their condoms and keep their needles to themselves: research published today in the open access journal Retrovirology shows that tourists, travel ...
New contraceptive device is designed to prevent sexual transmission of HIV
Medicine & Health / HIV & AIDS
May 19, 2009 |
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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 ...
Herpes medication does not reduce risk of HIV transmission
Medicine & Health / HIV & AIDS
May 08, 2009 |
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A recently completed international multi-center clinical trial has found that acyclovir, a drug widely used as a safe and effective treatment to suppress herpes simplex virus-2 (HSV-2), which is the most common cause of genital ...
New technology opens gateway to studying HIV-specific neutralizing antibodies
Medicine & Health / HIV & AIDS
Mar 16, 2009 |
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Many scientists believe a vaccine that prevents HIV infection will need to stimulate the body to make neutralizing antibodies, infection-fighting proteins that prevent HIV from entering immune cells. Previous research has ...
Report says 3 percent in DC have HIV or AIDS
Medicine & Health / HIV & AIDS
Mar 16, 2009 |
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(AP) -- A new report by D.C. health officials says that at least 3 percent of residents in the nation's capital are living with HIV or AIDS and every mode of transmission is on the rise.
Researchers' new goal: Drug-free remission for HIV infection
Medicine & Health / HIV & AIDS
Mar 05, 2009 |
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A group including leading academic and industry scientists has issued a challenge to researchers in the field of HIV/AIDS: find a way to effectively purge latent HIV infection and eliminate the need for chronic, suppressive ...
Using hair to manage HIV/AIDS and predict treatment success
Medicine & Health / HIV & AIDS
Mar 03, 2009 |
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UCSF researchers have found that examining levels of antiretroviral drugs in hair samples taken from HIV patients on therapy strongly predicts treatment success.
HIV is evolving to evade human immune responses
Medicine & Health / HIV & AIDS
Feb 26, 2009 |
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(PhysOrg.com) -- HIV is evolving rapidly to escape the human immune system, an international study led by Oxford University has shown. The findings, published in Nature, demonstrate the challenge involved ...
