What is AIDS? What causes AIDS?

AIDS stands for Acquired Immune Deficiency Syndrome. An HIV-positive person receives an AIDS diagnosis after developing one of the CDC-defined AIDS indicator illnesses. An HIV-positive person can also receive an AIDS diagnosis on the basis of certain blood tests (CD4+ counts) and may not have experienced any serious illnesses. A positive HIV test does not mean that a person has AIDS. A diagnosis of AIDS is made by a physician according to the CDC AIDS Case Definition.

Over time, infection with HIV (Human Immunodeficiency Virus) can weaken the immune system to the point that the system has difficulty fighting off certain infections. These types of infections are known as opportunistic infections. Many of the infections that cause problems or that can be life-threatening for people with AIDS are usually controlled by a healthy immune system. The immune system of a person with AIDS has weakened to the point that medical intervention may be necessary to prevent or treat serious illness.

How long does it take for HIV to cause AIDS?

Currently, the average time between HIV infection and the appearance of signs that could lead to an AIDS diagnosis is 8-11 years. This time varies greatly from person to person and can depend on many factors including a person's health status and behaviors. Today there are medical treatments that can slow down the rate at which HIV weakens the immune system. There are other treatments that can prevent or cure some of the illnesses associated with AIDS. As with other diseases, early detection offers more options for treatment and preventative health care.

How can I tell if I'm infected with HIV? What are the symptoms of AIDS?

The only way to determine whether you are infected is to be tested for HIV infection. You can't rely on symptoms to know whether or not you are infected with HIV. Many people who are infected with HIV don't have any symptoms at all for many years.

Similarly, you can't rely on symptoms to establish that a person has AIDS. The symptoms associated with AIDS are similar to the symptoms of many other diseases. AIDS is a diagnosis made by a doctor based on specific criteria established by the Centers for Disease Control and Prevention (CDC).

How does HIV make someone sick?

Over time, infection with HIV (human immuno-deficiency virus) can weaken the immune system to the point that the system has difficulty fighting off certain infections. These infections are known as opportunistic infections. Many of the infections that cause problems or that can be life threatening for people with AIDS are usually controlled by a healthy immune system. The immune system of a person with AIDS has weakened to the point that medical intervention may be necessary to prevent or threat serious illness.

How many people have HIV and AIDS?

Worldwide: UNAIDS estimates that 47.3 million people have been infected with HIV since the start of the global epidemic (42.9 million adults and 4.4 million children under 15). An estimated 13.9 million people have died with AIDS since the epidemic began (10.7 million adults and 3.2 million children under 15).

As of December 1998, there were an estimated 33.4 million people living with HIV infection or AIDS (32.2 million adults and 1.2 million children under 15). An estimated 5.8 million new HIV infections occurred in 1998. This represents almost 16,000 new cases per day. During 1998, HIV-associated illnesses caused the deaths of an estimated 2.5 million people, including 900,000 women and 510,000 children under 15.

I n the United States: According to the Centers for Disease Control and Prevention (CDC), there are between 650,000 and 900,000 people living with HIV. Through December 1998, a total of 688,200 cases of AIDS had been reported to the CDC; of this number, 410,800 persons (representing 60% of cases) have died.

Where did HIV come from?

Scientists have different theories as to the origin of HIV but none have been proven. We now know that the virus has existed in the United States, Haiti and Africa since at least 1977-1978. In 1979 rare types of pneumonia, cancer and other illnesses were being reported by doctors in Los Angeles and New York. The common thread was that these were conditions not usually found in persons with healthy immune systems. In 1982 the Centers for Disease Control and Prevention (CDC) officially named the condition AIDS (Acquired Immune Deficiency Syndrome). In 1984 the virus responsible for weakening the immune system was identified as HIV (Human Immunodeficiency Virus).

Can I get HIV from kissing?

Casual contact through closed-mouth or "social" kissing is not a risk for transmission of HIV. Because of the potential for contact with blood during "French" or open-mouth, wet kissing, CDC recommends against engaging in this activity with a person known to be infected. However, the risk of acquiring HIV during open-mouth kissing is believed to be very low. CDC has investigated only one case of HIV infection that may be attributed to contact with blood during open-mouth kissing. In this case both partners had extensive dental problems including gingivitis (inflammation of the gums). It is likely that there was blood present in both partners' mouths making direct blood to blood contact a possibility.

Can I get HIV from casual contact (shaking hands, hugging, using a toilet, drinking from the same glass, or the sneezing and coughing of an infected person)?

No. HIV is not transmitted by day to day contact in the home, the workplace, schools, or social settings. HIV is not transmitted through shaking hands, hugging or a casual kiss. You cannot become infected from a toilet seat, a drinking fountain, a doorknob, dishes, drinking glasses, food, or pets.

HIV is a fragile virus that does not live long outside the body. HIV is not an airborne or foodborne virus. HIV is present in the blood, semen or vaginal secretions of an infected person and can be transmitted through unprotected vaginal, oral or anal sex or through sharing injection drug needles.

Source: Centers for Disease Control and Prevention

Relevant Links

Advancing HIV Prevention - Centers for Disease Control and Prevention
AIDS Education Global Information System (AEGIS)
AIDS Info - A Service of the U.S. Department of Health and Human Services
American Academy of HIV Medicine - AAHIVM
Center for Interdisciplinary Research on AIDS at Yale University
Centers for Disease Control and Prevention - Division of HIV/AIDS Prevention
Community PROMISE: Peers Reaching Out and Modeling Intervention Strategies for HIV/AIDS Risk Reduction in their Community
Drug Abuse and HIV: Learn the Link - National Institute on Drug Abuse
Minority AIDS Initiative - Centers for Disease Control and Prevention
National AIDS Hotline
National Center for HIV, STD and TB Prevention - Centers for Disease Control and Prevention
Project Inform - Information, Inspiration and Advocacy for People Living with HIV/AIDS
Street Smart: Reducing HIV Risk Among Runaway and Homeless Youth - Centers for Disease Control and Prevention
The Body - An AIDS and HIV Information Resource
The Guardian Health Association, Inc.
UNAIDS - Joint United Nations Programme on HIV/AIDS
Women, Children and HIV - Resources for Prevention and Treatment