Gale Encyclopedia of Medicine.

Definition

Acquired immune deficiency syndrome (AIDS) is an infectious disease caused by the human immunodeficiency virus (HIV). There are two variants of the HIV virus, HIV-1 and HIV-2, both of which ultimately cause AIDS.

Description

AIDS was first recognized in the United States 1981 in homosexual men. Today is seen in both homosexual and heterosexual men and women. AIDS is the advanced form of infection with HIV virus. This virus may not cause recognizable symptoms for a long period after the initial exposure (latent period). As of early 2009, no vaccine was available to prevent HIV infection. Until such a vaccine is developed, all forms of HIV/AIDS therapy are focused on improving the quality and length of life for people who are infected by slowing or halting the replication of the virus and treating or preventing infections and cancers that often develop in people with AIDS. AIDS is one of the most devastating worldwide public health problems in recent history. The United States Centers for Disease Control and Prevention (CDC) estimated that in 2006 944,000 people in the United States had been diagnosed with AIDS since the disease was identified in 1981. In 2006, an additional 1-1.2 million Americans were diagnosed as infected with HIV but not yet showing symptoms (HIV positive). However, in early 2009, the CDC issued a statement that they now thought that earlier the HIV-positive estimates were too low, as many more people than were originally estimated are living with unreported or undiagnosed HIV infection. According to the August 2008 report issued by the Joint United Nations Programme on HIV/AIDS (visit website), as of 2007, approximately 33 million people worldwide are HIV positive. Over half of the 33 million are women and this statistic has remained stable for several years. The highest number of cases is found in sub-Saharan Africa and Southeast Asia. More than 70% of HIV infections are transmitted through sexual contact. Traditionally in the United States, the majority of cases were found in homosexual or bisexual men. In 2007, about half of new HIV cases were acquired by men having sex with other men. Fewer than 20% of HIV-positive Americans were women. However, this is not the case worldwide, where transmission by heterosexual individuals is common.

Prevention

As there is no cure for AIDS, prevention of HIV infection becomes extremely important in controlling the disease. Efforts to prevent the spread of AIDS include:

* Restricting sexual activity to a single partner and practicing safer sex (i.e., always using a condom). Besides avoiding the risk of HIV infection, condoms are successful in reducing other sexually transmitted diseases and unwanted pregnancies. Before engaging in a sexual relationship with someone, getting tested for HIV infection is recommended.

* Avoiding needle sharing among intravenous drug users.

* Donating one’s own blood before planned major surgery to prevent risk of infection from a blood transfusion, although blood supplies are extremely safe in the developed world.

* Practicing universal safety precautions when handling body fluids or needles. Healthcare professionals, first responders, and teachers, for example, are now trained in these precautions.

* Testing for HIV infection by anyone how suspects infection. If treated aggressively and early, the development of AIDS may be postponed. If HIV infection is confirmed, it is also vital to let past sexual partners know so that they can be tested and receive medical attention.