AIDS: A GLOBAL ASSESSMENT : A Primer on AIDS: Questions & Answers
In the six years since UCLA medical researchers diagnosed the first AIDS cases, the deadly infection has become one of the world’s foremost public health problems. Here are some often-asked questions about the disease.
Question: What is AIDS?
Answer: AIDS is an acronym for acquired immune deficiency syndrome, an invariably fatal infectious disease that attacks the body’s immune system, leaving a person vulnerable to a variety of life-threatening infections and tumors.
Q: What causes AIDS?
A: AIDS is caused by a virus, now called the human immunodeficiency virus, or HIV for short. The virus was identified by French and American researchers in 1984.
Q: How is the virus transmitted?
A: It is transmitted by sexual contact, by exposure to contaminated blood and from an infected mother to her newborn. The virus can also be found in saliva and breast milk, but actual transmission of the virus through either of these fluids appears to be rare.
Q: Where is the AIDS virus found?
A: It is found in many human fluids, most importantly blood, semen and vaginal secretions.
Q: How can one avoid exposure to the virus?
A: The risk of contracting the AIDS virus can be eliminated by not having sexual contact with AIDS virus carriers and not being exposed to their blood, such as by sharing needles to inject intravenous drugs. In addition, many AIDS researchers and public health officials believe the risk of sexual exposure to the AIDS virus can be minimized by using condoms. It has been shown that the virus cannot pass through the microscopic pores of condoms. But condoms are not foolproof protection against sexual exposure to the virus because they may break or not be used properly.
Q: What is the risk of being exposed to the AIDS virus by receiving a blood transfusion?
A: About 12,000 people in the United States became infected with the AIDS virus through contaminated blood transfusions. Most of them were exposed before the spring of 1985, when screening of the blood supply to detect contaminated blood began. The current risk to blood recipients is estimated to be 1 in 250,000 or less, according to Dr. Joseph R. Bove of Yale University.
Q: Will everyone who is infected with the AIDS virus eventually become ill with the disease?
A: It is not yet known. The vast majority of AIDS virus carriers will not become ill until at least three years after initial exposure to the virus. Some individuals have been infected with the AIDS virus for eight years or more and yet remain healthy. But between 20% to 30% will come down with AIDS within five years of infection. Also within five years, an additional 25% to 40% of those infected will develop ARC, or the AIDS-related complex. ARC is an imprecise diagnosis that includes patients with mild symptoms, such as swollen lymph glands as well as those who are seriously ill with infections or tumors but do not meet the exact criteria for diagnosing AIDS. ARC can be as deadly as AIDS; indeed many ARC patients eventually develop AIDS.
Q: How is infection with the AIDS virus diagnosed?
A: Through blood tests. The most widely used tests do not detect the virus particles themselves. Rather, they identify proteins called AIDS antibodies that are produced by the body’s immune system in response to the presence of the virus.
Q: What are these tests called?
A: The most common screening blood test is known as the ELISA (enzyme-lined immunosorbent assay). If the ELISA test result is negative, no further tests are done. If the result is positive, it should be confirmed by a second method, most often a more expensive and time-consuming but generally more reliable procedure known as the Western blot.
Q: What are the limitations of these tests?
A: Together, the ELISA and Western blot tests have proved to be among the most accurate diagnostic tools available. But like the majority of blood tests, AIDS antibodies measurements are not foolproof. A small number of people will have positive test results even though they have never been exposed to the AIDS virus; others may have erroneous negative results, most commonly when the tests are performed too soon after a person has been infected. It usually takes a month or two for AIDS antibodies to become detectable, but in some instances this has taken as long as six months.
Q: How widespread is the AIDS epidemic in the United States?
A: As of the end of July, 39,263 Americans had been diagnosed with AIDS and 22,548 had died. In addition, between 1 and 2 million Americans are estimated to be AIDS virus carriers.
Q: What are the prospects for developing AIDS treatments?
A: AIDS remains an incurable disease. One drug, called AZT, has been shown to be partially effective in delaying the development of serious infections and tumors in some AIDS patients. But AZT is very expensive and can cause serious side effects, such as anemia.
