Hopkins 24/7

Back to ABC News

This Thursday at 10/9c

This content requires javascript and flash player version 8.

Johns Hopkins Symptoms and Remedies

Johns Hopkins Medicine

Close Article Browser

AIDS (Acquired Immunodeficiency Syndrome)

What is it?

AIDS is the deadly final phase of infection with the human immunodeficiency virus (HIV). The virus, which is carried in blood, semen, and other body fluids, invades and destroys a specific type of white blood cell—the CD4 lymphocyte—a chief component of the body's immune system. The virus is spread primarily through sexual contact (homosexualand heterosexual), needle sharing among drug users, and from an infected woman to her infant. After initial infection, the virus multiplies over a period of several weeks, sometimes producing fever, fatigue, sore throat, skin rash, and other symptoms resembling a common virus like mononucleosis. Such symptoms tend to last only one or two weeks. The patient may then exhibit no symptoms for five to 10 years or more, although the virus is multiplying constantly and the patient remains infectious. As increasing numbers of CD4 lymphocytes are destroyed by the virus, symptoms such as swollen glands, fever, night sweats, diarrhea, and weight loss may appear.AIDS develops when the immune system becomes severely damaged (defined as a CD4 count less than 200 per microliter) and/or when opportunistic infections—normally kept at bay by healthy immune defenses—or unusual types of cancer (such as Kaposi's sarcoma or lymphoma) appear. Without treatment, survival after an opportunistic disease is short. Although not a cure, highly potent new drugs to treat HIV have dramatically reduced the rate of death from AIDS. When effective, these drugs reduce the amount of virus circulating in the blood (viral load) and often increase the CD4 count. Still, AIDS is a worldwide epidemic, with more than 30 million people infected.

What Causes It?

  • AIDS is caused by the human immunodeficiency virus (HIV), which is carried in the body fluids (blood, semen, female genital secretions, saliva, and breast milk) of infected patients. The virus progressively destroys the body's immune defenses, rendering the patient vulnerable to a multitude of potentially deadly secondary infections and cancers.
  • HIV is transmitted by exchange of body fluids during sexual contact with an infected partner and by exposure to contaminated blood or blood products, as occurs among intravenous drug users who share needles or hemophiliacs who've received multiple transfusions (improved testing of blood has recently eliminated HIV risk during a transfusion). An infected woman can pass the virus to her infant around the time of delivery or through breast milk. HIV is, however, a very fragile virus and does not survive long outside of the body. It is impossible to contract the virus by casual contact such as hugging, dry kissing, or drinking from the same glass as an infected person.

Prevention

  • HIV infection is preventable by practicing safe sex behaviors, including using condoms, and by limiting one's number of sexual partners over a lifetime (short of complete abstinence, an exclusive, mutually monogamous relationship is safest).
  • Do not use intravenous drugs; if you do, do not share needles.
  • Avoid contact with the blood of others.
  • Pregnant women with HIV should take medication to help prevent passing the virus to their child.

Diagnosis

  • Patient history and physical examination.
  • Blood tests. Presence of antibodies against HIV usually confirms the diagnosis. Measurement of the CD4 count indicates the extent of immune system impairment; measurement of viral levels in the blood indicates the risk of disease progression.
  • A diagnosis of AIDS is made when one or more opportunistic infections or cancers occur in someone with HIV, or when the CD4 count falls below 200 per microliter.

How to Treat It

  • Although HIV cannot be eradicated, combinations of anti-HIV drugs (protease inhibitors, nucleosides, and non-nucleosides) stop the virus from replicating and allow the immune system to function more normally. Anyone taking these drugs should be closely monitored by a physician.
  • Drug treatment should begin when immune function is being compromised and/or viral blood levels are high. Early treatment can prevent damage to the immune system for years. Even patients with late-stage AIDS can experience marked improvement in immune function, accompanied by reduced rates of illness.
  • Antibiotics may be prescribed to prevent specific infections from developing.
  • Pregnant women should be treated with combination drug therapy, which reduces the spread of HIV to the infant by 70 to 80 percent.
  • Vaccines and antibiotics are available to prevent opportunistic infections, which include pneumococcal pneumonia and Pneumocystis carinii pneumonia, two potentially life-threatening diseases that frequently affect people with AIDS.
  • Receiving a diagnosis of HIV infection is often emotionally devastating. Psychological counseling, support groups, and outreach from friends and family are invaluable.

When to Call a Doctor

  • Call a doctor if you believe you may have been exposed to HIV or if you experience any of the symptoms of HIV or AIDS.
  • Be tested if you have any reason to suspect that you have been infected with HIV. Many clinics offer confidential and anonymous testing.
  • All pregnant women should consider having an HIV test.