This transmission can involve anal, vaginal or oral sex, blood transfusion, contaminated hypodermic needles, exchange between mother and baby during pregnancy, childbirth, or breastfeeding, or other exposure to one of the above bodily fluids.

AIDS is now a pandemic.[6] In 2007, it was estimated that 33.2 million people lived with the disease worldwide, and that AIDS had killed an estimated 2.1 million people, including 330,000 children.[7] Over three-quarters of these deaths occurred in sub-Saharan Africa,[7] retarding economic growth and destroying human capital.[8]

Genetic research indicates that HIV originated in west-central Africa during the late nineteenth or early twentieth century.[9][10] AIDS was first recognized by the U.S. Centers for Disease Control and Prevention in 1981 and its cause, HIV, identified in the early 1980s.[11]

Although treatments for AIDS and HIV can slow the course of the disease, there is currently no vaccine or cure. Antiretroviral treatment reduces both the mortality and the morbidity of HIV infection, but these drugs are expensive and routine access to antiretroviral medication is not available in all countries.[12] Due to the difficulty in treating HIV infection, preventing infection is a key aim in controlling the AIDS epidemic, with health organizations promoting safe sex and needle-exchange programmes in attempts to slow the spread of the virus.

contents

* 1 Symptoms
o 1.1 Pulmonary infections
o 1.2 Gastrointestinal infections
o 1.3 Neurological and psychiatric involvement
o 1.4 Tumors and malignancies
o 1.5 Other opportunistic infections
* 2 Cause
o 2.1 Sexual transmission
o 2.2 Exposure to blood-borne pathogens
o 2.3 Perinatal transmission
o 2.4 Misconceptions
* 3 Pathophysiology
o 3.1 Cells affected
+ 3.1.1 The effect
+ 3.1.2 Molecular basis
* 4 Diagnosis
o 4.1 WHO disease staging system
o 4.2 CDC classification system
o 4.3 HIV test
* 5 Prevention
o 5.1 Sexual contact
o 5.2 Exposure to infected body fluids
o 5.3 Mother-to-child transmission (MTCT)
* 6 Treatment
o 6.1 Antiviral therapy
o 6.2 Experimental and proposed treatments
o 6.3 Alternative medicine
* 7 Prognosis
* 8 Epidemiology
* 9 History
* 10 Society and culture
o 10.1 Stigma
o 10.2 Economic impact
o 10.3 AIDS denialism
o 10.4 Active pursuit of HIV infection
* 11 Notes and references
* 12 Further reading
* 13 External links