Currently, more than 1 million people in the United States are living with HIV/AIDS, according to the National Institute of Allergy and Infectious Diseases, or NIAID. HIV stands for human immunodeficiency virus, and AIDS stands for acquired immunodeficiency syndrome. AIDS is the end stage of HIV infection. It has no cure, but antiretroviral drugs suppress the virus, making it possible for infected persons to live for many years.
Features
You can be infected with HIV for years and not be aware of it, but eventually HIV levels build up in the blood and begin to attack your immune system. Specifically, the virus destroys CD4 positive T cells, the white blood cells that your body uses to fight off infections. Without sufficient levels of these T cells, your immune system weakens and can no longer fight off infections and diseases properly, allowing AIDS to develop. An AIDS diagnosis occurs, according to the NIAID, when someone infected with HIV has "one or more opportunistic infections, such as pneumonia or tuberculosis, and has a dangerously low number of CD4+ T cells." The Institute defines a dangerously low number as "less than 200 cells per cubic millimeter of blood."
History
In 1959, doctors diagnosed the first known case of HIV-1, the predominant strain of HIV, in a human, according to the Centers for Disease Control and Prevention, or CDC. A blood sample from a man in Kinshasa, Democratic Republic of the Congo, contained the virus, but how he was infected is unknown. Documentation by the CDC shows that HIV has been in the United States since at least the late 1970s. From 1979 to 1981, reports of unusual types of cancer, pneumonia and other diseases started to come from doctors in New York and Los Angeles. The patients were primarily men who had sex with other men.
The number of HIV-1 infections in the United States continued to rise. In 1982, public health officials first used the term "acquired immunodeficiency virus" to describe the rare types of cancer, pneumonia and other illnesses in people who were previously healthy. In that same year, health officials began formal tracking of AIDS cases. In 1983, researchers discovered the virus that leads to AIDS. Eventually, the official name for the virus became human immunodeficiency virus, or HIV. Scientists now believe that the virus originated in chimpanzees in West Africa and transferred to humans when hunters were exposed to blood.
Prevalence
In 2007, the number of people living with HIV/AIDS worldwide was approximately 33 million, reports the NIAID, and that same year 2.7 million others became newly infected with HIV. In the United States, more than 1 million people have HIV/AIDS, and 21 percent of those are unaware of the infection. Since the AIDS epidemic began in the United States in 1981, the number of people dying from AIDS totals 565,927.
Symptoms
Within one to two months after initial exposure to HIV, you may experience flulike symptoms, such as headache, fever, tiredness and enlarged lymph nodes in the area around the neck and groin. Many people fail to connect these symptoms to HIV and attribute them to the flu or some other viral infection. Some have no symptoms at all. When the virus eventually weakens the immune system and AIDS develops, typical symptoms include rapid weight loss, fevers and night sweats, extreme fatigue for no reason and diarrhea for longer than a week. Lymph glands in the groin, neck or armpits may stay swollen, you may have develop sores around the mouth, genitals or anus, and you may develop pneumonia. Pink, red, purple or brown blotches may develop on or under the skin or inside the nose, mouth or eyelids, and you may have depression, memory loss and other neurological problems.
Risk Factors
HIV travels in the blood, semen and vaginal fluid of persons who have the virus. The virus spreads through exchange of these bodily fluids---such as in unprotected vaginal, oral or anal sex---or by injecting drugs using a shared needle. AIDS has no cure, and no vaccine exists to prevent HIV infection. The best way to protect against HIV/AIDS is to practice safe sex, do not share needles and do not have multiple sex partners.
