Understanding And Preventing AIDS: A Book for Everyone

AIDS stands for "acquired immune deficiency syndrome." A "syndrome" is a group of clinical symptoms that make up a disease or an abnormal condition. ("Clinical" means seen in the doctor's office, not discovered by laboratory tests.) In a syndrome, not all symptoms have to appear in anyone patient. Syndromes may be caused by many different things, but in AIDS the syndrome is caused by a deficiency (defect) in the body's immune system. The immune system defends the body against disease.
The diseases of the AIDS syndrome are caused by germs we encounter every day. In fact, some of these germs permanently live, in small numbers, inside the human body. When the immune (defense) system weakens, these germs have the opportunity to multiply freely, so the diseases these germs cause are called "opportunistic diseases."
AIDS first claimed national attention in 1981 when five homosexual men in Los Angeles were simultaneously hospitalized due to Pneumocystis carinii pneumonia (PCP). At that time, PCP normally occurred in kidney transplant patients whose immune systems had been chemically suppressed (blocked). PCP was usually cured by antibiotic drugs. The PCP is these men, however, resisted drug therapy.