Of the 47,106 AIDS cases reported to the CDC in 1992 from the United States, Puerto Rico, and the territories, 16,218 (34.4 percent) were associated with drug injection (injection drug user IDU-associated AIDS cases). In 1992, IDU-associated AIDS cases included heterosexual IDUs (70.4 percent), male IDUs who also reported having sex with other men (15.0 percent), non-IDU heterosexual partners of IDUs (12.4 percent), and children born to mothers who were either IDUs or the sex partners of IDUs (2.2 percent).

In 1992, IDU-associated AIDS cases made up 49 percent and 48 percent of all AIDS cases for blacks and Hispanics, respectively, compared with 19 percent for whites. Also, there are major differences in the percentages of reported IDU-associated AIDS cases in different regions of the United States. In 1992, the highest percentage of IDU-associated AIDS cases (as a percentage of total reported AIDS cases from each area) occurred in Puerto Rico (67 percent) and the Northeast (52 percent). Percentages reported in the South (30 percent), North Central region (25 percent) and West (19 percent) were substantially lower.

How HIV Is Transmitted by Injection Drug Use

HIV can be transmitted through injection drug use when the blood of an HIV-infected drug user is transferred to a drug user who is not yet HIV infected. Needles and syringes are the primary drug injection equipment involved in transferring HIV-infected blood between drug injectors. This transfer of HIV-infected blood occurs almost exclusively through the multiperson use, or sharing, of drug injection equipment. There are two drug injection activities that involve introducing blood into the needle and syringe. The first activity is to draw blood into the syringe to verify that the needle is inside a vein (so the drug can be injected intravenously). The second, following drug injection, is to refill the syringe several times with blood from the vein to "wash out" any heroin, cocaine, or other drug left in the syringe after the initial injection. If even a tiny amount of HIV-infected blood is left in the syringe, even an amount too small to be visible, the virus can be transmitted to the next user.

The Significance of HIV Transmission Among Drug Injectors

In recent years, adult and adolescent IDUs have represented approximately one quarter of all people testing positive for human immunodeficiency virus (HIV) at publicly funded HIV counseling and testing sites. Persons who inject drugs and share drug injection equipment are at high risk of acquiring HIV because HIV is transmitted very efficiently through such sharing. HIV transmission among IDUs and their sex and needle-sharing partners, and to their newborns, is a major factor in the continuing spread of HIV, especially among racial/ethnic minority populations.

The Role of Alcohol and Non-Injection Drug Use in HIV Transmission

HIV transmission also is occurring among people who trade sex for non-injected drugs, particularly "crack" cocaine, and their partners. Trading sex for drugs often is associated with unprotected sex and having multiple sex partners. Further, the use of non-injected drugs or alcohol can place a person at risk for HIV transmission in part because these substances lessen inhibitions and reduce reluctance to engage in unsafe sex.

Recent reports suggest that crack cocaine smokers may be at high risk of acquiring HIV infection heterosexually. Preliminary data from a CDC-sponsored study revealed a very high prevalence of HIV infection in New York City and Miami among street-recruited young adults (ages 18-29) who smoked crack, but never injected drugs or had male homosexual intercourse -- especially among those who traded sex for crack. In these two cities, HIV infection rates were higher among the female study participants than among the males (32 percent vs. 11 percent in New York; 45 percent vs. 11 percent in Miami). Analysis of the data attributed the high prevalence of HIV infection to the likelihood of exchanging sex for drugs and of having genital ulcer diseases, particularly syphilis and herpes. HIV transmission may be facilitated by the presence of open genital sores that are caused by these diseases.

The practice of trading sex for drugs has contributed not only to the spread of HIV infection, but also to large increases in rates of sexually transmitted diseases (STD) in recent years. There is a clear relationship between "crack" use and the current syphilis epidemic, which has led to a parallel epidemic among the nation's newborns. In 1992, in New York City alone, nearly 900 babies were born infected with syphilis.

CDC Prevention Efforts

Current CDC prevention efforts for IDUs include support and evaluation of street outreach programs in a variety of settings that help encourage drug users to discontinue drug use and seek treatment. These programs further emphasize the importance of never sharing drug injection equipment, using sterile needles and syringes, or, if sterile needles and syringes are not available, using bleach to disinfect needles and syringes that will be reused.

CDC, the Center for Substance Abuse Treatment (Substance Abuse and Mental Health Services Administration), and the National Institute on Drug Abuse (National Institutes of Health) released a joint bulletin on April 19, 1993, that contains provisional recommendations on how bleach disinfection should be done. This bulletin indicates that (1) sterile, never-used needles and syringes are safer than bleach-disinfected, previously used needles and syringes, and (2) bleach disinfection of needles and syringes continues to have an important role in reducing the risk of HIV transmission for injecting drug users who have no other safer option than to reuse or share needles or syringes. Copies of the bulletin can be obtained from the CDC National AIDS Clearinghouse or the National Clearinghouse for Alcohol and Drug Information.

CDC also supports HIV counseling and testing of drug users in drug treatment centers and other sites (including STD clinics and approximately 430 correctional facilities in 42 states, the District of Columbia, and Puerto Rico), thereby reaching drug users both in and out of treatment programs. Additionally, programs that are designed to prevent sexual HIV transmission are often aimed at high-risk populations in communities where drug use is common.

For more information, contact:
CDC National AIDS Hotline: 1-800-342-AIDS (2437)
Spanish: 1-800-344-7432
Deaf: 1-800-243-7889

U.S. Department of Health and Human Services
Public Health Service
Centers for Disease Control and Prevention
November 1993