Acquired Immunodeficiency Syndrome (AIDS), human viral

disease that ravages the immune system, undermining the

body's ability to defend itself from infection and disease. Caused

by the human immunodeficiency virus (HIV), AIDS leaves an

infected person vulnerable to opportunistic infections. Such

infections are harmless in healthy people, but in those whose

immune systems have been greatly weakened, they can prove

fatal. Although there is no cure for AIDS, new drugs are

available that can prolong the life spans and improve the quality

of life of infected people.

Infection with HIV does not necessarily mean that a person has

AIDS. Some people who have HIV infection may not develop any

of the clinical illnesses that define the full-blown disease of AIDS

for ten years or more. Physicians prefer to use the term AIDS for

cases where a person has reached the final, life-threatening

stage of HIV infection.

II. PrevalencePrint section

AIDS was first identified in 1981 among homosexual men and

intravenous drug users in New York and California. Shortly after

its detection in the United

States, evidence of AIDS

epidemics grew among

heterosexual men, women,

and children in

sub-Saharan Africa. AIDS

quickly developed into a

worldwide epidemic,

affecting virtually every

nation. By 2000 an

estimated 34.7 million

adults and 1.4 million

children worldwide were

living with HIV infection or

AIDS. The World Health

Organization (WHO), a

specialized agency of the

United Nations (UN),

estimates that from 1981

to the end of 2000 about

21.8 million people died as

a result of AIDS. More

than 4.3 million of those who died were children under the age of

15.

Word Count: 266