HIV

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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.

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

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Antiretroviral therapy associated with increase in pregnancy in sub-Saharan Africa

Medicine & Health / HIV & AIDS

19 hours ago | not rated yet | 0

In PLoS Medicine this week a study conducted in a multi-country HIV treatment program in sub-Saharan Africa has found that pregnancy rates increase in HIV-infected women after they start antiretroviral therapy (ART).

Study suggests when dealing with fungi, it's best to attack from both sides

Biology / Cell & Microbiology

Feb 08, 2010 | not rated yet | 0

(PhysOrg.com) -- Each year, 83,000 life-threatening fungal infections cost us $2.6 billion. And this number will only go up as HIV infection, cancer chemotherapy, and organ transplants bump up the immune-compromised population ...

For HIV-infected children, quality of caregiver relationship is crucial

Medicine & Health / HIV & AIDS

Feb 05, 2010 | not rated yet | 0

A new study of children in Ukraine has found that for the growing number of HIV-infected children, the quality of care and the relationship between children and their caregivers play an important role in their development. ...

High-risk populations may not accept an HIV vaccine, study finds

Medicine & Health / HIV & AIDS

Feb 04, 2010 | not rated yet | 0

(PhysOrg.com) -- While study participants were only moderately accepting of an HIV vaccine overall, researchers hope social marketing and education can help address some of the stumbling blocks to acceptance.

Scientists find two compounds that lay the foundation for a new class of AIDS drug

Medicine & Health / HIV & AIDS

Feb 03, 2010 | 5 / 5 (3) | 0 |

A team of scientists at The Scripps Research Institute has identified two compounds that act on novel binding sites for an enzyme used by the human immunodeficiency virus (HIV), the virus that causes AIDS. The discovery lays ...

FDA liver risk warning for Bristol-Myers HIV drug

Medicine & Health / Medications

Feb 01, 2010 | not rated yet | 0

(AP) -- Federal health officials say patients taking a Bristol-Myers Squibb drug for HIV have reported a rare, but potentially fatal liver disorder.

HIV researchers solve key puzzle after 20 years of trying (w/ Video)

Medicine & Health / HIV & AIDS

Jan 31, 2010 | 4.9 / 5 (24) | 2 |

Researchers have made a breakthrough in HIV research that had eluded scientists for over 20 years, potentially leading to better treatments for HIV, in a study published today in the journal Nature.

New vaccine effective in preventing TB in African patients with HIV infection

Medicine & Health / HIV & AIDS

Jan 29, 2010 | not rated yet | 0

Investigators from Dartmouth Medical School (DMS) have reported results of a clinical trial showing that a new vaccine against tuberculosis, Mycobacterium vaccae (MV), is effective in preventing tuberculosis in people with ...

New compound could be alternative strategy for preventing HIV infection

Medicine & Health / HIV & AIDS

Jan 25, 2010 | not rated yet | 0

With the help of effective drug therapies, HIV patients are living longer, healthier lives. Now, researchers want to improve these drug therapies and develop alternative preventative strategies, such as vaginal ...

Study predicts HIV drug resistance will surge

Medicine & Health / HIV & AIDS

Jan 25, 2010 | not rated yet | 0 |

(PhysOrg.com) -- New research predicts that a wave of drug-resistant HIV strains will emerge in San Francisco within the next five years, hampering efforts to control the pandemic.

Control of herpes symptoms does not reduce HIV transmission, international study found

Medicine & Health / HIV & AIDS

Jan 25, 2010 | not rated yet | 0

Research from a five-year international clinical study shows that acyclovir, a commonly prescribed drug used to suppress symptoms of the herpes virus, does not affect HIV transmission by people with both viruses.

HIV infection prematurely ages the brain

Medicine & Health / HIV & AIDS

Jan 22, 2010 | not rated yet | 0 |

HIV infection or the treatments used to control it are prematurely aging the brain, researchers at Washington University School of Medicine in St. Louis and the University of California-San Diego have found.

PrEP treatment prevented HIV transmission in humanized mice

Medicine & Health / HIV & AIDS

Jan 21, 2010 | not rated yet | 0 |

Systemic pre-exposure administration of antiretroviral drugs provides protection against intravenous and rectal transmission of HIV in mice with human immune systems, according to a new study published January 21, 2010 in ...

Herpes medication does not reduce risk of HIV transmission

Medicine & Health / HIV & AIDS

Jan 20, 2010 | 1 / 5 (1) | 1 |

A five-year international multi-center clinical trial has found that acyclovir, a drug widely used as a safe and effective treatment taken twice daily to suppress herpes simplex virus-2 (HSV-2), which is the most common cause ...

HIV: Positive lessons from home-based care

Medicine & Health / HIV & AIDS

Jan 19, 2010 | not rated yet | 0

Intensive home-based nursing in HIV/AIDS patients significantly improves self-reported knowledge of HIV, awareness of medications, and self-reported adherence to medication programmes, according to a new Cochrane Systematic ...