Using or sharing unsterile needles, cotton swabs, rinse water, and cookers, such as when injecting heroin, cocaine, or other drugs, leaves a drug abuser vulnerable to contracting or transmitting HIV. Another way people may be at risk for contracting HIV is simply by using drugs of abuse, regardless of whether a needle and syringe are involved. Research sponsored by NIDA and the National Institute on Alcohol Abuse and Alcoholism has shown that drug and alcohol use can interfere with judgment about sexual (and other) behavior and thereby affect the likelihood of engaging in unplanned and unprotected sex. This increases the risk for contracting HIV from infected sex partners.
Since the epidemic began, injection drug use has directly and indirectly accounted for more than one-third (36 percent) of AIDS cases in the United States, and an estimated 28 percent of diagnosed AIDS cases among adults and adolescents were related to injection drug use in 2002. According to a Centers for Disease Control and Prevention (CDC) analysis of HIV surveillance data, of the 859,000 cumulative AIDS cases reported through December 2002, a total of 209,920 (25 percent) were among injection drug users (IDUs).*
From 1998 to 2002, an estimated 240,268 AIDS diagnoses were due directly to injection drug use, with males accounting for roughly 72 percent of these cases. Over this same period, there has been a gradual decline in the number of new AIDS diagnoses associated with injection drug use for both males and females.
Among racial and ethnic groups, as of December 2002, 43 percent of cumulative AIDS cases reported among adult and adolescent Hispanic males were directly or indirectly related to injection drug use, as were 42 percent among African American males. The percentages were greater among females, however. Fifty-eight percent of cumulative AIDS cases reported among adult and adolescent Hispanic females were directly or indirectly related to injection drug use, as were 57 percent of cases reported among White females and 51 percent among African American females. By comparison, only 18 percent of the cumulative AIDS cases reported through 2002 among White males were directly or indirectly related to injection drug use.
The gradual decline over the period from 1998 to 2002 in the number of new AIDS diagnoses among IDUs contrasts with the steady to slightly increasing numbers of new AIDS diagnoses among men who have sex with men (MSM). However, the greater contrast is with the number of new AIDS diagnoses due to heterosexual contact, which has increased steadily from 1998 to 2002 for both adult and adolescent males (18 percent) and females (16 percent).
Noninjection drugs (such as “crack” cocaine) also contribute to the spread of the epidemic when users trade sex for money, or when they engage in high-risk sexual behaviors while under the influence of drugs. One CDC study of more than 2,000 young adults in three inner-city neighborhoods found that crack smokers were three times more likely to be infected with HIV than nonsmokers.