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HIV Infection and AIDS

(Human Immunodeficiency Virus and Acquired Immunodeficiency Syndrome)


Human immunodeficiency virus (HIV) is a virus that attacks the white blood cells called helper T cells (CD4). These cells are part of the immune system. They fight off infections and disease. As a result, an HIV infection can leave you vulnerable to severe illnesses.
AIDS is a late stage of HIV infection. It reflects severe damage to the immune system. One or more opportunistic infections will also likely exist. Opportunistic infections are a type of infection that only occur in people with compromised immune systems.


HIV is spread through contact with HIV-infected blood or other body fluids. This includes semen, vaginal fluid, and breast milk. The infection may be the result of HIV-1 or HIV-2 virus.
AIDS is caused by the destruction of T cells. The destruction is caused by the HIV virus.
Immune System
Immune system white blood cell
HIV destroys white blood cells vital to the immune system.
Copyright © Nucleus Medical Media, Inc.
HIV is most commonly spread through:
Rarely, HIV can be spread through:

Risk Factors

Factors that increase your chance of getting HIV include:
HIV infection increases the chances of getting AIDS.


HIV may not cause symptoms for a number of years.
Early symptoms may appear a month or two after becoming infected. They may last a couple of weeks and be similar to the flu or mononucleosis. These include:
After these initial symptoms pass, there may be no symptoms for months to years. The following symptoms may occur over the years:
If left untreated, HIV infection progresses to AIDS. This may happen when the number of T helper cells fall below certain levels and opportunistic infections arise. People with AIDS are susceptible to many health complications. These may include:


Your doctor will ask about your symptoms and medical history. A physical exam will be done. To confirm a diagnosis of HIV infection, your doctor will run tests. These may include:


Medications can prevent, delay, or control the development of AIDS in many people infected with HIV.

Drugs That Fight HIV

Antiviral drugs are often given in combination. Categories of these drugs include:
  • Nucleoside reverse transcriptase inhibitors
  • Nonucleoside reverse transcriptase inhibitors
  • Protease inhibitors
  • HIV-1 integrase inhibitors
  • HIV-1 fusion inhibitors
  • CC chemokine receptor 5 antagonists

Drugs That Fight AIDS-Related Infections and Cancers

People who have developed AIDS may be given other medications to help fight infections that are more likely to occur with a weak immune system. These may include antibiotics or antifungal medications.


In general, to reduce your chances of getting HIV infection, take these steps:
If you are a healthcare worker or work in a correctional facility, take these steps:
If you live in a household with an HIV-infected person, take these steps:
If you are infected with HIV, take these steps to prevent spreading HIV to others:


American Foundation for AIDS Research

Centers for Disease Control and Prevention


AIDS Committee of Toronto

Canadian AIDS Society


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3/8/2007 DynaMed's Systematic Literature Surveillance : Auvert B, Taljaard D, Lagard E, Sobngwi-Tambekou J, Sitta R, Puren A. Randomized, controlled intervention trial of male circumcision for reduction of HIV infection risk: the ANRS 1265 Trial. PLoS Med . 2005;2(11):e298. Epub Oct 25, 2005. Bailey RC, Moses S, Parker CB, et al. Male circumcision for HIV prevention in young men in Kisumu, Kenya: a randomised controlled trial. Lancet . 2007 Feb 24;369(9562):643-656. Gray RH, Kigozi G, Serwadda D, et al. Male circumcision for HIV prevention in men in Rakai, Uganda: a randomised trial. Lancet . 2007 Feb 24;369(9562):657-666.

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