The HIV epidemic has shifted over the past 30 years, from the first reported cases in the early s, to an estimated high of 3. An estimated 2. Estimated HIV incidence by region in adults 15 to 49 years of age, and Accessed May 9, Accessed May 9, ; with permission.
The previously healthy men had contracted pneumonia, and two died. Today, more than a million Americans have the virus. Being diagnosed with HIV was once a death sentence. Now, a year-old with HIV who begins treatment early can expect to live to their early 70s. The disease, which attacks the immune system, can be controlled by modern-day antiretroviral medications. Around 1. An estimated 39, Americans were newly diagnosed with HIV in
The human immunodeficiency virus HIV targets the immune system and weakens people's defence systems against infections and some types of cancer. As the virus destroys and impairs the function of immune cells, infected individuals gradually become immunodeficient. Immune function is typically measured by CD4 cell count. Immunodeficiency results in increased susceptibility to a wide range of infections, cancers and other diseases that people with healthy immune systems can fight off. The most advanced stage of HIV infection is acquired immunodeficiency syndrome AIDS , which can take from 2 to 15 years to develop if not treated, depending on the individual.
Approximately 1. About 15 percent of them 1 in 7 are unaware they are infected. Gay, bisexual, and other men who have sex with men bear the greatest burden by risk group, representing an estimated 26, of new HIV infections per year. Some people may have HIV but not know it. After about 5 years of substantial declines, the number of annual HIV infections began to level off in , to about 39, infections per year.