1. HIV AIDS Myths and Facts Slideshow Pictures
2. Take the HIV/AIDS Quiz
3. AIDS Retrospective Slideshow Pictures

Medical Author:

Eric S. Daar, MD

Eric S. Daar, MD

Dr. Daar received his undergraduate degree from UCLA and medical degree from Georgetown University School of Medicine. He completed an internship and residency in internal medicine at Cedars-Sinai Medical Center and his clinical and research fellowship in infectious diseases at Cedars-Sinai Medical Center and UCLA.

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Medical Editor:

Jay W. Marks, MD

Jay W. Marks, MD

Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.

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In this Article

• HIV facts
• What is the history of HIV, and when was HIV discovered?
• What tests are used in the diagnosis of HIV?
• How is HIV transmitted (spread)?
• What happens after an exposure to the blood or genital secretions of an HIV-infected person?
• What are HIV symptoms and signs in men, women, and children?
• What laboratory tests are used to monitor HIV-infected people?
• What are the key principles in managing HIV infection?
• Should patients with the flu- or mono-like illness of primary HIV infection be treated?
• What about treatment for HIV during pregnancy?
• What can be done for people who have severe immunosuppression?
• What is the future for HIV-infected individuals with regards to treatment simplification and cure research?
• What is in the future for preventing HIV transmission?
• HIV-AIDS FAQs
• Patient Comments: HIV - How it's Spread
• Patient Comments: Human Immunodeficiency Virus (HIV, AIDS) - Symptoms
• Find a local Infectious Disease Specialist in your town
• Human Immunodeficiency Virus (HIV, AIDS) Index

The history of the human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) dates back to 1981, when homosexual men with symptoms of a disease that now are considered typical of AIDS were first described in Los Angeles and New York. The men had an unusual type of lung infection (pneumonia) called Pneumocystis carinii (now known as Pneumocystis jiroveci) pneumonia (PCP) and rare skin tumors called Kaposi's sarcomas. The patients were noted to have a severe reduction in a type of cell in the blood (CD4 cells) that is an important part of the immune system. These cells, often referred to as T cells, help the body fight infections. Shortly thereafter, this disease was recognized throughout the United States, Western Europe, and Africa. In 1983, researchers in the United States and France described the virus that causes AIDS, now known as HIV, belonging to the group of viruses called retroviruses. While HIV infection is required to develop AIDS, the actual definition of AIDS is the development of a low CD4 cell count (<200 cells/mm³) or any one of a long list of complications of HIV infection ranging from a variety of so-called "opportunistic infections," cancers, neurologic symptoms, and wasting syndromes.

In 1985, a blood test became available that measures antibodies to HIV that are the body's immune response to the HIV. The test used most commonly for diagnosing infection with HIV is referred to as an ELISA. If the ELISA finds HIV antibodies, the results must be confirmed, typically by a test called a Western blot. HIV antibody tests remain the best method for diagnosing HIV infection. Recently, tests have become available to look for these same antibodies in saliva, some providing results within one to 20 minutes of testing. A major advance toward increasing the number of people tested for HIV is the availability of the FDA-approved OraQuick home HIV antibody test that is self-administered using saliva. Antibodies to HIV typically develop within several weeks of infection. During this interval, patients have virus in their body but will test negative by the standard antibody test, the so-called "window period." In this setting, the diagnosis can be made if a test is used that actually detects the presence of virus in the blood rather than the antibodies, such as tests for HIV RNA or p24 antigen. Recently, a new test has been approved that measures both HIV antibodies and p24 antigen, shrinking the duration of the window period from infection to diagnosis. There also are many testing centers around the country that are routinely screening blood samples that are HIV-antibody negative for HIV RNA.

Although the tests for detecting HIV infection continue to improve, they still require that people volunteer for testing. It is estimated that approximately 20% of those infected with HIV in the United States are unaware of their infection because they have never been tested. In order to decrease the number that are unaware of their HIV infection status, in 2006, the Centers for Disease Control and Prevention recommended that all people between the ages of 13 and 64 years be provided HIV testing whenever they encounter the health care system for any reason. In addition, resources are available to facilitate people finding local HIV testing centers (http://www.hivtest.org).