Acquired immune deficiency syndrome (AIDS)
AIDS is a syndrome (many symptoms and manifestations) caused by the human immunodeficiency virus (HIV). HIV compromises the functioning of the human immunologic system, preventing it from adequately perform its function of protecting the human organism against external aggressions, such as bacteria, other virus, parasites and carcinogen cells.
Even though a person is HIV-positive, this person may not be with AIDS. AIDS represents the most advanced stage of HIV infection, when the immunologic system is severely compromised and several infections known as opportunist infections may appear.
HIV infection is a long term process that goes through several stages. The duration and severity of each stage depend on many factors related to both the virus and the infected person and it may present many different symptoms. In general, the elapsed time between exposition to HIV and the beginning of symptoms varies from 5 to 3 months. The symptoms may result in persistent flu, progressive weight loss, physical strength decrease, intermittent fever, muscular pains, nocturnal sweating, diarrhea, and other reactions. When a HIV infection is in a very advanced stage, some opportunistic diseases start to arise such as: tuberculosis, pneumonia, chronic diarrhea.
Forms of infection:
Unprotected sexual intercourse with a seropositive person; direct contact with contaminated blood (which includes sharing needles for the use of injectable drugs, blood and/or blood-derived products transfusions, accidents with biological materials, occupational or not, that generate direct contact from these with mucous membranes, wounded or hurt skin and deep tissues of the body, allowing access to sanguineous flow); from a HIV-positive mother to her child, during pregnancy, labor and delivery and through breast feeding.
Prevention:
Safer sex practices (monogamous relationship with HIV-negative partner and condom use in all sexual intercourses).
When handling blood it is also recommended extreme care (use of disposable syringe, blood transfusion only after HIV blood test, use of gloves when manipulating potentially contaminated wounds or liquids). At present, there isn't an effective vaccine for preventing HIV infection.