AIDS, Living with

Acquired immunodeficiency syndrome (AIDS) is a collection of symptoms and infections resulting from specific damage to the immune system. It is caused by the human immunodeficiency virus (HIV). HIV is transmitted through direct contact with mucous membranes or bodily fluids, such as blood, semen, preseminal fluid, vaginal fluid, and breast milk. Transmission can occur through vaginal, anal, or oral sex; blood transfusions; hypodermic needles; childbirth; or breast-feeding.

HIV is thought to have originated in sub-Saharan Africa during the 20th century and first appeared in the United States in 1981. It is currently a pandemic of enormous magnitude, with an estimated 38.6 million people infected worldwide. According to the Joint United Nations Programme on HIV/AIDS (UNAIDS) [Page 45]and the World Health Organization (WHO), as of January 2006, AIDS has killed more than 25 million people. In 2005 alone, AIDS claimed an estimated 2.4 to 3.3 million lives, of which more than 570,000 were children. One-third of these deaths have occurred in sub-Saharan Africa, retarding economic growth and destroying human capital in the region.

HIV targets specific cells in the human immune system, namely CD4+ T-cells, dendritic cells, and macrophages. When initially infected with the virus, a person may experience flu-like symptoms. As the body responds to the infection, there is often a clinically latent phase lasting a median of nine to 10 years. However, the rate of clinical progression varies widely between individuals, ranging from two weeks up to 20 years. The late stage of the condition leaves an individual's immune system severely compromised—often defined as having a CD4$+ count of less than 200 cells per microliter (normal is between 500–1,800 cells/μL). At this level of immunodeficiency, people become susceptible to opportunistic infections, such as Pneumocystis jiroveci pneumonia, tuberculosis, cryptosporidiosis, cryptococcus neoformans, toxoplasmosis, cytomegalovirus (CMV), and mycobacterium avium complex (MAC). Additionally, people are at increased risk of developing certain cancers, for example, Kaposi's sarcoma and lymphoma.

Although there is no cure for HIV and AIDS, treatments do exist that have effectively slowed the virus's progression. Antiretroviral treatment reduces both the mortality and the morbidity of HIV infection. Access remains a compelling issue, as antiretroviral medications are not available in many countries. To further complicate the matter, an HIV/AIDS diagnosis brings with it a stigma that is frequently as severe as the associated life-threatening conditions, making prevention campaigns and treatment exceedingly difficult.