Magic Johnson's announcement yesterday that he is retiring from professional basketball because he tested positive for the human immunodeficiency virus is a complex situation. What follows are some questions and answers to help explain the issues.
Question: What causes AIDS, the acquired immune deficiency syndrome?
Answer: AIDS is caused by a virus known as human immunodeficiency virus, or HIV. Unlike the viruses that cause colds and flu, HIV does not leave the body after attacking the cells. HIV permanently combines its genetic material with the genetic material of the body's host cells. Then it uses those cells to make copies of itself. Each cell becomes, in effect, a little virus factory.
Q: Does Johnson have AIDS?
A: He has tested HIV positive, but Johnson said he does not yet have fully developed AIDS.
Q: If Johnson does not have fully developed AIDS, why doesn't he continue playing?
A: Johnson's physician, Michael Mellman, said that the sport is too physically demanding. The medical field has debated how much a person who is HIV positive can and cannot do. Because NBA players sometimes get hurt and bleed, there is a remote chance of exposing someone to infected blood.
Q: How did Johnson contract the virus?
A: Neither Johnson nor his physician offered any explanation.
Q: How long does it take before an infected person gets sick?
A: Sometimes only a few months, but more often several years. The virus can remain silent in the body for 10 years or longer -- and a person can look and feel perfectly healthy. Scientists do not know what triggers the disease, but eventually the virus begins to wear away at the immune system.
Q: What are some symptoms?
A: They include fatigue, fever, night sweats, unexplained weight loss, swollen lymph glands, shingles, diarrhea or yeast infections. As the disease progresses, the person also might develop rare cancers or a serious respiratory infection known as pneumocystis carinii pneumonia.
Q: Has Johnson suffered from any of the symptoms above?
A: In October of 1985, Johnson was temporarily out because he suffered from shingles.
Q: How is AIDS transmitted?
A: The virus is passed through unprotected (meaning, without a condom) anal and vaginal sexual intercourse. It also is transmitted by intravenous drug abusers who use -- and then share -- hypodermic needles. It can be passed by a woman to her fetus during pregnancy, and through breast milk. In the past, it also was transmitted through blood transfusions, which are now tested for the virus. The virus cannot be passed through casual contact with others, or through the air.
Q: What drugs are available to treat AIDS?
A: Two drugs have been approved to treat the underlining viral condition, AZT or zidovudine, and DDI, also known as dideoxyinosine or didanosine. The drugs seem to prolong the lives of individuals who already have AIDS. They also delay symptoms in infected people who are not sick yet, and slows the progress of the disease in those with early symptoms. AZT can produce some serious side effects in people with fully developed AIDS. But appears to be less toxic in those who do not yet have symptoms or who only show early signs of the disease.
Several other drugs also are available to treat the many conditions caused by AIDS. Among these are foscarnet and gancyclovir, which help prevent Cytomegalovirus retinitis, an eye infection that often leads to blindness. Also, the Food and Drug Administration recently approved another drug to combat the severe anemia associated with AZT, thus avoiding the need for blood transfusions. This drug is called EPO, or R-erythropoietin.
Q: What else can be done?
A: In addition to taking AZT, medical authorities have recommended preventive measures for infected persons who do not have symptoms but whose immune systems show some damage. A test can determine whether the number of helper T-cells has dropped to dangerous levels. Doctors suggest taking "aerosol pentamidine" to prevent pneumocystis carinii pneumonia, which can be fatal. Also, there is growing evidence that daily doses of an antibiotic sold under the names Bactrim and Septra are more effective in preventing pneumocystis.
Q: What medication is Johnson taking?
A: His physician said no medications have been administered yet.
Q: Will there ever be a cure for AIDS?
A: Probably not; researchers are convinced that someday drugs will be available to control AIDS the same way diseases such as diabetes or high blood pressure are controlled.