On June 1981 American scientists informed about the first clinical case of the decease after the illness that later was called the acquired immune deficiency syndrome (AIDS). In 1983 they found out the cause of the decease - human immunodeficiency virus (HIV). 30 years later the epidemic of AIDS has spread all over the world. More than 60 million people were infected with HIV. As on March 1, 2011 in the Republic of Belarus 11929 HIV cases are reported (194 are children).