HIV & AIDS

Major gaps in HIV programs in Africa

HIV management in developing countries varies with socioeconomic and structural circumstances, with two Flinders University studies finding examples of key ways to close the gap for those worst affected in developing countries.

Diseases, Conditions, Syndromes

Looking at the social side of COVID-19 through HIV research

While the COVID-19 pandemic is often described as unprecedented, there is a recent viral epidemic that researchers in UConn's Institute for Collaboration on Health, Intervention and Policy (InCHIP) say can offer lessons about ...

HIV & AIDS

Results of 'highly significant' HIV transmission study published

A new Liverpool led study, published in The Lancet HIV, addresses an important knowledge gap around the management of women who start HIV treatment in late pregnancy, with the ultimate aim of reducing mother to child transmission ...

Obstetrics & gynaecology

Microbiome therapy protects against recurrent bacterial vaginosis

A product containing healthy vaginal bacteria has proved effective against recurrent bacterial vaginosis (BV), an extremely common vaginal infection that is associated with preterm birth, HIV infection and problems with in ...

HIV & AIDS

Researchers discover how HIV hides from treatment

Even after successful antiretroviral therapy, HIV can hide dormant in a tiny number of immune system cells for decades and re-emerge to threaten the life of its host. Now Yale University researchers have discovered a molecular ...

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HIV

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.

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