6. Is the author optimistic about controlling AIDS in the future?
(Check the correct answer( Yes / No Give two reasons to support your answer.
Living With the Virus
When and how HIV turns into AIDS 1 We all die of something, and the only thing that changed for Magic Johnson when he tested positive for the AIDS virus is that he now knows what he will probably die from, if not necessarily when. There are, according to estimates by the Centers for Disease Control, between 1 million and 1.5 million people like Johnson in America, and roughly 10 million in the world -- people whose blood conceals a minute speck of nucleic acid with the power to lay bare their immune defenses and leave them helpless in the face of the most ordinary infections. What sets Johnson apart, other than being famous, is that he knows he has it. Most of the people with the AIDS virus don't know who they are and neither does anyone else.
2 In the decade since AIDS was first described and named, medical science has made great progress against it. Doctors have identified its cause, the human immunodeficiency virus (HIV) that infects and destroys the T-cells that are a key component of the immune system. They have devised reliable tests for the presence of HIV, thereby minimizing the risk of contracting it through contaminated blood transfusions. They have come up with drugs to slow the growth of the virus in the body and delay the onset of symptoms, and drugs to treat the complications of AIDS that actually kill. They have devised rules, which, if everyone followed them, would virtually halt the spread of the virus among people who are not yet infected. But there is one thing they have not been able to do, even once: they have never cured it. Although there are reports of a few cases of spontaneous recovery (a highly controversial assertion, to be sure), for all practical purposes a person who has been infected with HIV is infected for life.
3 Accordingly, people in Johnson's situation inhabit a kind of medical limbo, made possible by HIV's remarkably long period of latency. Except for a brief flu like illness shortly after contracting the infection, people with the AIDS virus may feel completely healthy, as Johnson does, and exhibit no medical symptoms at all. They can continue like that indefinitely, while the virus erodes the immune system "the way the surf works on a beach," according to Dr. Michael Gottleib, the Los Angeles immunologist who published the first clinical description of AIDS patients. Over time, symptoms may appear, such as weight loss or the night sweats that have been likened to a dousing with a bucket of cold water. Eventually a threshold is crossed. The immune system breaks down, the person gets sick with one of the distinctive infections that are markers for AIDS and his case is added to the 195,718 Americans who have been diagnosed with AIDS. Although some people get sick soon after infection, the median interval is between 10 and 11 years, and that includes statistics from the years before drugs such as AZT were available. The upper limit, if there is any, is unknown. That is the good news. The bad news is that once AIDS itself is diagnosed -- the full blown disease, not just the infection -- the chance of surviving more than three years is around one in 10.
4 And, of course, from shortly after someone is infected until the day he dies, he can pass the virus on to someone else. It is precisely the long latency of the AIDS virus that has enabled it to spread so widely. Despite its lethality, AIDS is actually a very difficult disease to catch. The virus cannot survive for more than a few minutes outside the human body, and has been transmitted, as far as is known, only by infected blood, semen or vaginal secretions. Hemophiliacs and surgery patients can get HIV via a contaminated transfusion of whole blood or blood products, although that is rare now that blood is routinely tested. Infants can get it from infected mothers, either in utero across the placenta or by contact in passing through the birth canal; the virus has also been found in breast milk and studies have shown that it can be transmitted that way. At least 40 and perhaps as many as several hundred health workers have acquired the virus from the blood of patients, but transmission in the other direction almost never occurs. (The case of the Florida dentist who infected Kimberly Bergalis and four others of his patients was the only reported instance of its kind.) And the virus can spread among drug users who share needles, accounting for the second largest number of total AIDS cases in America.
5 And, of course, it can spread via unprotected sexual contact -- usually, but not always, when the infected partner is a male. This is partly because more men than women have the virus in the first place. The early victims of the AIDS infection in America were mostly homosexual men, however today 20 percent of those infected are women.
Straight Talk about a Deadly Disease
can avoid the deadly risks of unprotected sex and intravenous drugs.
Who Is at Risk? * People who have unprotected sex
outside a stable, monogamous
* People who have multiple sex
partners, or partners whose HIV
status is unknown.
*Men and women who have
unprotected sex with homosexual
or bisexual men.
*Men and women who have unprotected sex with intravenous drug users, or with the partners of intravenous drug users.
* Male and female IV drug users who share their needles with others. This is the second-largest risk group.