AIDS was first described in 1981 in New York and Los Angeles during an unusual incidence of Pneumocystis carinii pneumonia and Kaposi’s sarcoma in homosexual men who had no known underlying immunodeficiency. In the United States, 51% of all AIDS cases have been men who reported sexual contact with other men. In central Africa and in some areas of the Caribbean, sexual transmission appears to be primarily heterosexual. Other sexually transmitted diseases such as herpes, syphilis, and chancroid may facilitate transmission of HIV through ulcerations in the mucous membranes.

Bloodborne pathogen transmission has occurred: (1) by transfusion of blood from HIV infected donors; (2) through receipt of clotting factors for treatment of hemophilia; (3) through the sharing of needles for injection of drugs; (4) through unprotected sexual intercourse with an HIV-infected person (5) through accidents in health care settings with needles or other sharps contaminated with HIV infected blood; and (6) accidental blood splashes on mucous membranes. Up to 30% of infants born to HIV infected mothers may be infected with HIV themselves. The exposure occurs either in utero or during labor and delivery. There are also reports of HIV virus transmission during breast-feeding. Post-exposure prophylaxis is available for occupational exposure to HIV. The CDC recommends that workers who have an exposure incident must be evaluated within 1-2 hour for a risk assessment and possible prophylactic treatment with antiviral drugs. All potential HIV exposures must be reported and evaluated within 1-2 hour to insure optimal treatment.

The disease is characterized by a very long incubation period, which is the time of infection to the onset of life-threatening opportunistic infections, and malignancies that signal the development of full-blown AIDS. Disease progression with HIV is divided into several stages according to types of infections or symptoms reported and are associated with progressive decline in CD4+ cells.

• Acute Infection: Within 1 to 4 weeks after infection, an individual may experience acute retroviral syndrome, which will manifest itself in a mononucleosis-like or flu-like illness. Unexplained fever, lymphadenopathy, myalgia (muscle pain), arthralgia (joint pain), headache, sore throat, unexplained diarrhea, fatigue, loss of appetite and rash are signs and symptoms of this usually self-limiting stage.

• Asymptomatic Infection: During this stage which occurs 4 to 12 weeks after infection, most individuals will develop HIV antibodies (seroconversion). These individuals may be asymptomatic for months to years but can transmit the virus to others.

• Symptomatic HIV infection/AIDS Related Complex (ARC): During this stage which may last from months to several years after infection, many of the symptoms of acute infection reemerge. Oral candidiasis (oral thrush), oral hairy leukoplakia, Herpes zoster in individuals younger than 60 years and ulcerative Herpes simplex may also occur.

• AIDS: Many HIV infected individuals go on to develop AIDS months to several years after initial infection. Their immune systems become severely weakened turning normally mild, opportunistic or rare infections into potentially fatal diseases. Indicator diseases of AIDS include: Pneumocystic carinii pneumonia, the most common cause of death; fungal diseases of the esophagus, trachea, bronchi or lungs especially with Candida or Cryptococcus; Cytomegalovirus (CMV) retinitis; Kaposi’s sarcoma; primary brain lymphoma; extrapulmonary disseminated mycobacteria tuberculosis; any mycobacterial disease caused by mycobacteria other than Mycobacterium tuberculosis, especially Mycobacterium avium complex or Mycobacterium kansasii; pulmonary tuberculosis; recurrent pneumonia; invasive cervical cancer; brain toxoplasmosis; disseminated fungal diseases, especially coccidioidomycosis and histoplasmosis; HIV associated encephalopathy (AIDS dementia); HIV associated wasting syndrome (slim disease); HIV disease progression is often associated with decrease of CD4 + cell count throughout.