HIV & AIDS 101


Acquired Immune Deficiency Syndrome (AIDS) is the end-stage result of HIV infection. By the time someone develops AIDS, the virus has significantly damaged the body's defenses (immune system). Thus, people with AIDS develop diseases that most healthy people can normally resist or control. Since the virus can enter the brain and other organs throughout the body, many people with AIDS have trouble with movement, memory and body functions.

  • Acquired: A disease which is acquired through specific actions or behaviors. Not innate.
  • Immune: The body's basic defense system, which helps regulate organisms in the body, defend against new infections, and help us to rebound when sickness does occur.
  • Deficiency: AIDS causes a weakening of a person's immune response.
  • Syndrome: A group of symptoms or illnesses that affect people with AIDS. AIDS is not a disease itself, only a classification of HIV disease.


Human Immunodeficiency Virus (HIV), is the virus that causes AIDS.

  • Human: HIV is a human virus. It can only be acquired through HUMAN contact. It is not spread to or from any animal.
  • Immunodeficiency: HIV attacks a person's immune system and causes a deficiency in a person's immune response.
  • Virus: HIV is a virus. Viruses are the smallest known disease causing agents.


  • A Person With AIDS (PWA) is simply a person living with this disease, and should not be referred to as an AIDS "victim" or "patient."

Disease Progression

  • Initial Infection: The point of infection is when the virus enters the body and takes hold. A person is infectious to others the moment she/he becomes infected. Most healthy people have between 800 and 1200 T-cells at this time.
  • Window Period: A person can be infected with HIV and still test negative if they test during the window period. The window period is the time between potential exposure to HIV infection and the point when the test will give an accurate result. For the 4th Generation Alere Determine™ HIV-1/2 Ag/Ab Combo test, the window period is 4 weeks.
  • Asymptomatic HIV: This is the period of time when a person is infected with HIV but shows no obvious signs or symptoms. A person with HIV infection is often completely healthy throughout this period with a T-cell count of over 500. This period is variable in length, but can often last from 8 - 15 years.
  • Symptomatic HIV: During this period a person develops clear symptoms of immune deficiency that are not severe enough for an AIDS diagnosis. These symptoms don't appear in everyone and begin to occur when a person's T-cell count drops below 500. This period is extremely variable in length. Some common symptoms include swollen lymph nodes, fever, fatigue, rashes, and weight loss.
  • AIDS: AIDS is the end stage of HIV disease and is characterized by major defects in the immune system and/or the presence of opportunistic infections. An AIDS diagnosis occurs when a person's T-cell levels drop below 200 or one or more opportunistic infections occur. Some opportunistic infections include: Kaposi's Sarcoma, Tuberculosis, cancers, CMV, and PCP (pneumocystis carinii pneumonia). These infections often lead to death in a person with AIDS.


HIV can be transmitted when an infected body fluid from one individual enters the bloodstream of another. Five body fluids have been identified as the primary source of HIV transmission. These fluids are: blood, penile secretions, rectal fluid, vaginal secretions, and breast milk. The most common way that people become infected with HIV include:

  • Unprotected Sex: Vaginal, oral or anal intercourse with someone who has the virus.
  • Sharing Needles: Using needles that have been used by someone else.
  • Mother to Infant: Exposure of a baby to an infected mother's blood during pregnancy or delivery, or through breast feeding.
  • Blood Transfusions: Blood transfusions are largely a historical concern. Blood transfusions, blood components or blood clotting factors or organ transplants have been very safe since HIV testing of these procedures began in 1992.

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