News tagged with hiv

Related topics: aids · hiv infection · virus · immune system · human immunodeficiency virus

More secondary schooling reduces HIV risk

Longer secondary schooling substantially reduces the risk of HIV infection—especially for girls—and could be a very cost-effective way to halt the spread of the virus, according to researchers from Harvard T.H. Chan School ...

Jun 29, 2015
popularity57 comments 0

Bill Gates hopeful of AIDS vaccine in 10 years

Billionaire and philanthropist Bill Gates, who spends millions of dollars on AIDS drug development, said Friday he hoped for a vaccine against the disease within the next decade as a cure remains far off.

Jun 26, 2015
popularity12 comments 0

PrEP is not linked to greater risk for depression

A new paper out of the iPrEx study—a randomized, placebo-controlled trial of daily oral HIV pre-exposure prophylaxis (PrEP) in men and transgender women who have sex with men—reported no link between taking Truvada for ...

Jun 19, 2015
popularity50 comments 1

New model to study HIV latency in brain cells

Over 35 million people worldwide are currently infected by HIV. Antiviral therapies can keep the virus from multiplying. However, no drug can cure infection so far, because various cell types continue to carry the virus in ...

Jun 18, 2015
popularity12 comments 0


Human 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.

This text uses material from Wikipedia, licensed under CC BY-SA

Subscribe to rss feed