Epidemiology is defined as "the study of how the disease is distributed in populations and of the factors that influence or determine this distribution." Epidemiologists try to discover why a disease develops in some people and not in others.

AIDS Cases First Recognized

AIDS was first recognized in the United States in 1981. In Washington State, the first reported case of AIDS was in 1982. Since then, the number of AIDS cases has continued to increase both in the U.S. and other countries. In 1983, HIV was discovered to be the cause of AIDS (see chart below).

HIV and AIDS Cases Continued

People who are infected with HIV come from all races, countries, sexual orientations, genders, and income levels. Globally, most of the people who are infected with HIV have not been tested, and are unaware that they are living with the virus. The U.S. Centers for Disease Control and Prevention (CDC) estimates that a quarter of people with HIV are unaware that they are living with the virus. The number of HIV-infected people worldwide has grown dramatically. HIV cases only became reportable to the Department of Health in the fall of 1999. AIDS cases have been reportable since 1984.

Contact the State AIDS Hotline at 1-800-272-2437 for updated information on reported HIV and AIDS cases in Washington.

The CDC estimates that there are between 1,039,000 to 1,185,000 persons infected with HIV in the United States. Additionally, it is estimated that 40,000 persons in the United States become newly infected with HIV each year. In the U.S., there are estimated to be over 17,000 people with AIDS who are dying each year in the U.S. As therapies have improved, fewer people have died of AIDS each year. However, the treatments have not reduced the number of new infections. The United Nations AIDS Program estimates there were 38.6 million people in the world living with HIV or AIDS in 2005. An estimated 4.1 million people worldwide became infected with HIV in 2005. Half of these new infections were in people between the ages of 15-24 There were 3 million deaths worldwide from AIDS in 2000.

For current HIV and AIDS statistics, visit these websites:

http://www.doh.wa.gov/cfh/hiv.htm (go to Prevention & Education)

http://hivinsite.ucsf.edu/

http://www.cdc.gov/

http://www.unaids.org/en/HIV_data/2006GlobalReport

Decrease in AIDS Deaths

Antiretroviral therapy (ART) is the recommended treatment for HIV infection. ART involves taking a combination (regimen) of three or more anti-HIV medications daily. ART prevents HIV from multiplying and destroying infection-fighting CD4 cells. This helps the body fight off life-threatening infections and cancer. ART can’t cure HIV, but anti-HIV medications help people infected with HIV live longer, healthier lives.