HIV and AIDS: Who Is Affected

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Topic Overview

HIV and AIDS can affect anyone. Worldwide, an estimated 33 million people are living with HIV or AIDS.footnote 1 In the United States, more than a million people are infected with HIV.footnote 2 Many of these people do not know they are infected.

Since the use of antiretroviral therapy (ART) became widespread in 1996, the incidence of AIDS has decreased. Factors responsible for the decline in the incidence of new AIDS cases include:footnote 3

  • Fewer people are becoming infected with HIV today than in the early 1980s.
  • Improved treatments for HIV infection. ART slows the rate at which HIV multiplies in the body. This helps keep a person's immune system healthy longer, which may slow the rate at which opportunistic diseases (such as pneumonia) develop.
  • More effective treatments are available to prevent HIV-related infections.



  1. United Nations Programme on HIV/AIDS (UNAIDS), World Health Organization (WHO) (2009). AIDS Epidemic Update: December 2009. Available online:
  2. U.S. Centers for Disease Control and Prevention (2008). HIV prevalence estimates—United States, 2006. MMWR, 57(39): 1073–1076.
  3. Centers for Disease Control and Prevention (2008). HIV transmission rates in the United States—CDC Fact Sheet. Available online:


ByHealthwise Staff
Primary Medical Reviewer E. Gregory Thompson, MD - Internal Medicine
Specialist Medical Reviewer Peter Shalit, MD, PhD - Internal Medicine

Current as ofNovember 14, 2014