Diseases, Conditions, Syndromes

Undiagnosed and untreated disease identified in rural South Africa

A comprehensive health-screening program in rural northern KwaZulu-Natal, South Africa, has found a high burden of undiagnosed or poorly controlled non-communicable diseases, according to a study published in The Lancet Global ...

HIV & AIDS

AI app could help diagnose HIV more accurately

Pioneering technology developed by UCL and Africa Health Research Institute (AHRI) researchers could transform the ability to accurately interpret HIV test results, particularly in low- and middle-income countries.

Diseases, Conditions, Syndromes

A better molecular test to detect tuberculosis

The 'Xpert Ultra' molecular test has a greater capacity than its predecessor ('Xpert MTB/RIF') in detecting tuberculosis cases, either passively (i.e. people who attend the hospital with disease symptoms) or actively (searching ...

HIV & AIDS

40 years of HIV/AIDS: Will the epidemic end?

June marks the 40th anniversary of the first scientific report describing pneumocystis pneumonia, which later became known as acquired immune deficiency syndrome (AIDS). More than 32 million people have died worldwide from ...

HIV & AIDS

HIV has detrimental effect on children's growth and bone strength

Children growing up with HIV infection have concerning deficits in skeletal strength which become more apparent towards the end of pubertal growth, finds the largest study to date to investigate the link between HIV and skeletal ...

Diseases, Conditions, Syndromes

Start-up launches India's first COVID home test kit

Indian start-up Mylab Discovery Solutions hopes that its inexpensive COVID-19 home test kit—the country's first—will help the massive South Asian nation better track the pandemic's spread among its 1.3-billion people.

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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.

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