AIDS

AIDS, or acquired immunodeficiency syndrome, is a serious disease. Millions of people have died from AIDS since the 1980s. Scientists have not yet found a cure, but they can treat the disease effectively.
Causes

Tiny particles called viruses cause many diseases. The particular virus that causes AIDS is called human immunodeficiency virus (HIV). HIV enters the body through contact with infected blood or other body fluids. Coughing, sneezing, and handshaking do not spread the virus.
HIV kills helper T cells in the body. Helper T cells are a type of white blood cell. They are part of the body's immune system, which fights off disease. The body loses its ability to fight off disease when its helper T cells die.
Symptoms

A new HIV infection often causes symptoms, or signs, that are similar to those of influenza (flu). They usually last only a week or two. After they clear up, an infected person may show no signs of illness for years. However, such a person can still pass the virus to other people.

Because of their weak immune systems, most HIV-infected people eventually come down with other infections. A person who has these infections is said to have AIDS. The most common infections include tuberculosis and a certain type of pneumonia. People with AIDS also frequently develop a cancer called Kaposi sarcoma. The AIDS virus may also attack the nervous system and cause brain and eye damage. Death often follows.

Prevention and Treatment

Despite much research, no cure or effective vaccine for HIV infection has yet been found. However, people can prevent HIV infection. The main way to do this is to keep out of contact with possibly infected blood or body fluids.

Researchers have developed a number of drugs that can stop HIV from doing damage. Drug treatment has added years to the lives of many people with HIV infections.

History

AIDS probably started in Africa., where it existed for many years without being recognized. The disease was first identified in the United States in 1981. Most of the early AIDS cases in the United States affected homosexual men. Other early AIDS patients were drug users who got the disease from needles. HIV was identified as the cause of the disease in 1983. By 1985 tests to detect the virus had been developed. Within a decade of the first AIDS case, the disease spread all over the world. It became clear that all kinds of people could get the disease. People with AIDS included patients infected during blood transfusions, women infected by their male sexual partners, and children infected by their mothers before birth. Public awareness of AIDS spread as famous people became victims of the disease, including the movie star Rock Hudson and the tennis champion Arthur Ashe.

By the early years of the 21st century well over 20 million people had died of AIDS worldwide, and nearly 40 million were living with HIV or AIDS. Nearly 3 million people died from AIDS in 2003 alone. African countries south of the Sahara accounted for about two thirds percent of all infections. The region of Asia and the Pacific accounted for another 20 percent. Experts estimated that about 14,000 people were becoming infected every day.