Scientists believe that HIV, human immunodeficiency virus, originally mutated in Africa in the late 1800s before it was identified in the United States in 1981. The term AIDS, or acquired immunodeficiency syndrome, was created shortly thereafter to describe the collage of symptoms that develop with progression of HIV infection. The U.S. Centers for Disease Control and Prevention estimates that the total number of people infected with HIV in the U.S. is around 1.1 million.
Initial HIV Infection
According to MayoClinic.com, when first infected with HIV, many people feel no initial symptoms, although they are still able to transmit the virus to others. HIV infection occurs only from infected blood, semen or vaginal secretions entering the host. HIV is classified as a retrovirus that destroys CD-4 cells, which are a type of white blood cell and a crucial part of the immune system. Symptoms of HIV infection are related to a weakened immune system unable to fight opportunistic microorganisms that would normally pose no health risk.
Early HIV Infection Symptoms
Many people who become infected with HIV eventually develop flu-like symptoms two to four weeks post exposure. Typically, these symptoms include mild fever, headache, sore throat, swollen lymph nodes, muscle and joint pain, rashes and mild diarrhea, as cited in "Professional Guide to Diseases." These flu-like symptoms can last up to a few months, but typically disappear for a significant portion of time, sometimes 10 or more years.
Later HIV Infection Symptoms
The symptoms of HIV infection eventually return, which is sometimes referred to as the acute HIV phase. The symptoms of the acute phase can be identified by the areas of the body most affected; mainly the immune system, the gastrointestinal tract, the lungs, the nervous system and the skin and mucous membranes, as cited in "AIDS in the Twenty-First Century."
The main symptoms of a compromised immune system from HIV infection include swollen lymph nodes in the neck, underarms and groin, as well as high fevers, night sweats and profound fatigue. Gastrointestinal symptoms occur because of bacterial proliferation and include severe and chronic diarrhea, nausea, reduced appetite and rapid weight loss. Bacterial pneumonia from Pneumocystis carinii is a serious respiratory condition that often stems from HIV infection, causing shortness of breath and a dry, unproductive cough. With a compromised immune system, a variety of viral and fungal infections proliferate on the skin and mucous membranes, such as candidiasis of the mouth, also known as oral thrush. Aside from the depression, anxiety and fear caused by becoming aware of the HIV infection, other nervous system symptoms can include peripheral neuropathy, confusion and muscle weakness.
AIDS Symptoms
According to MayoClinic.com, without treatment for HIV infection, the disease typically progresses to AIDS in about 10 years. By the time AIDS develops, the immune system has been almost completely destroyed and the body is susceptible to a great variety of opportunistic infections. Symptoms are similar to the acute HIV phase, but more advanced.
Technically, an AIDS diagnosis is made when a person's CD-4 cell count falls below 200 and they experience an "AIDS-defining complication," such as Pneumocystis jiroveci pneumonia, cytomegalovirus, tuberculosis, toxoplasmosis, or cryptosporidiosis. These are all diseases that signify a severely injured immune system.
References
- Avert.org: HIV and AIDS Timeline
- The U.S. Centers for Disease Control and Prevention: HIV Prevalence Estimates 2006
- MayoClinic.com: HIV and AIDS Symptoms
- "Professional Guide to Diseases - 8th Edition"; Springhouse; 2008
- "AIDS in the Twenty-First Century, Fully Revised and Updated Edition: Disease and Globalization"; Tony Barnett et al; 2006
