Sex workers and their clients represent traditional "core" transmitters of STDs (Plummer and Ngugi, 1990). Extremely high rates of STDs, including HIV infection, have been reported among sex workers in the United States (Darrow, 1992). For example, in a national study of more than 1,300 female sex workers, 56 percent had serological evidence of past or current hepatitis B virus infection (Rosenblum et al., 1992). Studies in the late 1970s and early 1980s found that up to 22 percent of sex workers screened in some U.S. cities were infected with gonorrhea (Plummer and Ngugi, 1990). As mentioned previously, exchanging sex for drugs is a major factor in the recent upsurge in syphilis infections in several large cities. In addition to unprotected sex with multiple partners, female sex workers also are likely to have other factors that increase their risk for STDs, such as intravenous drug use, a history of being victims of sexual abuse and violence, and inadequate access to health care (Rosenblum et al., 1992).
Policies related to sex workers have ranged from punitive interventions such as criminalizing prostitution, as in the United States, to legalizing and controlling it, as is the case in many European countries. In those European countries, sex workers must submit to periodic health examinations and testing for STDs (Plummer and Ngugi, 1990). Studies indicate that screening and treatment programs to reduce the prevalence of STDs among sex workers, while ignoring the legal and moral debates regarding prostitution, may be effective in controlling outbreaks of treatable STDs, such as syphilis and chancroid, but less effective for untreatable STDs or STDs that are more widespread in the general population (Plummer and Ngugi, 1990). More recent approaches combine peer health educators, promotion of barrier methods, screening and treatment, and counseling (CDC, 1996a).
Estimates of the number of runaway and homeless adolescents in the United States vary from hundreds of thousands to millions (AMA, Council on Scientific Affairs, 1989). Adolescents living on the streets are at risk for many health problems, including STDs (Sherman, 1992). One study showed that approximately one-third of runaways in Los Angeles detention facilities had an STD at the time of detention (Manov and Lowther, 1983). Runaways and homeless adolescents are at increased risk for STDs because they tend to be more sexually active than other adolescents (Hein et al., 1978); have multiple high-risk sexual behaviors that include trading sex for drugs or money (AMA, Council on Scientific Affairs, 1989; Sugerman et al., 1991; Sherman, 1992; Forst, 1994); have high levels of substance use (Manov and Lowther, 1983; Sugerman et al., 1991; Sherman, 1992); and are frequently sexually and physically abused by others (AMA, Council on Scientific Affairs, 1989). A survey of states regarding pregnancy