The Centers for Disease Control (CDC), has collected data on AIDS since 1981 and approximately 95% of all persons with AIDS fall into one or more of the following categories:
• Sexually active Gay and bisexual men
• Intravenous drug abusers
• Patients who have had transfusions with blood or blood products
• Persons with Hemophilia or other coagulating disorders
• Persons from Haiti and central African countries
• Male and female prostitutes and their sex partners
• Heterosexuals who have had sex with someone with AIDS
• Infants born to infected mothers
• Infants who contract AIDS nursing from infected mothers
About 5% of persons with AIDS do not fall into any of these categories, but researchers believe that they came into contact with AIDS through similar ways. Some died before accurate case histories could be developed, and others refused to provide information.