H. J. A. Van Haastrecht

Risk reduction among intravenous drug users in Amsterdam under the influence of AIDS.

We evaluated the impact of a needle/syringe exchange program among 263 drug users in the period December 1985 to April 1988. Participants in this study were asked about their risk-behavior at three different visits. We found no increase in the proportion injecting drugs or in the frequency of intravenous drug use. A strong decrease in borrowing and lending of used needle/syringes was found and this behavioral change was not dependent on learning human immunodeficiency virus (HIV) serostatus. Although use of the exchange program increased over time, reduction in needle sharing was mainly an effect of the study with only a limited impact of the exchange program. We conclude that ample provision of needles and syringes is an important starting point but in itself not enough to produce the necessary drastic change in risk behavior. Intensive counseling of the drug user is also needed.

The course of the HIV epidemic among intravenous drug users in Amsterdam, The Netherlands.

To determine if behavioral changes in intravenous drug users in Amsterdam have retarded the HIV (human immunodeficiency virus) epidemic in this group in recent years, we report that: HIV-antibody seroprevalence in annual samples of injectors has been constant over the years 1986-89; HIV-antibody incidence in a cohort of injectors appears to have decreased from 1986 to 1987 and stabilized after that until 1989; acute hepatitis B incidence in all drug users in Amsterdam declined rapidly between 1985-89. It is concluded that changes in drug use behavior so far appear to have resulted in a stabilization of the epidemic among injectors, at a level with a still disturbingly high incidence rate of 5-6 per 100 person-years.

HIV infection and STD in drug addicted prostitutes in Amsterdam: potential for heterosexual HIV transmission.

To assess the potential role of drug using prostitutes in the heterosexual transmission of human immunodeficiency virus (HIV), 117 prostitutes, recruited from December 1985 to November 1987 at a weekly evening sexually transmitted diseases (STD) clinic for drug using prostitutes only, were studied for the prevalence of HIV and STD. Intravenous drug use was reported by 96 (82%) of the women. Antibody to HIV was found in 35/117 (30%) women, all but one of whom had been using drugs intravenously. Most (73, 62%) of the prostitutes reported having had more than 2000 clients each in the preceding five years. In the six months preceding enrollment to the study they had practised mainly vaginal (106/117) and orogenital (82/117) intercourse; 90% (105/117) reported frequent use of condoms in vaginal intercourse and 65% (68/105) in orogenital intercourse. Despite frequent condom use, 81% (84/104) contracted one or more STD in this period. Considering the high incidence of HIV and STD and the finding by others that the presence of STD may facilitate transmission of HIV, we conclude that the potential for HIV transmission from these prostitutes to their clients (and vice versa) was clearly present.

HIV prevalence and risk behaviour among prostitutes and clients in Amsterdam: migrants at increased risk for HIV infection.

OBJECTIVES--To study groups of prostitutes and clients of prostitutes in order (i) to determine HIV prevalence and sexual risk behaviour, (ii) to determine differences between samples recruited within and outside a clinic for sexually transmitted diseases (STD) and (iii) to determine correlates of inconsistent condom use (ICU) among both groups. DESIGN--Participants were interviewed and anonymously tested for HIV-antibody; approximately half were recruited at a clinic for sexually transmitted diseases (STD) and half at prostitute working places. SETTING--An STD clinic and prostitute working places in Amsterdam in 1991. SUBJECTS--201 female prostitutes without a history of injecting drugs and 213 male clients of female prostitutes. MAIN OUTCOME MEASURES--antibodies to HIV, consistency of condom use in commercial vaginal contacts in the preceding 6 months. RESULTS--HIV prevalence was low: three prostitutes (1.5%; 95% CI 0.5-4.6%) and one client (0.5%; 95% CI 0.1-3.3%) were infected. All three HIV positive prostitutes originated from AIDS-endemic countries, came to the Netherlands only recently and were recruited outside the STD clinic. Large differences between subgroups resulted from the two recruitment methods: while clients of prostitutes with relatively high risk behaviour were strongly represented among the STD clinic sample, high risk prostitutes were underrepresented in this sample. Consistent condom use (with 100% of contacts) was reported by 66% of prostitutes and 56% of clients of prostitutes. Inconsistent condom use was found to be high among prostitutes who had migrated from Latin America and among migrant clients of prostitutes. CONCLUSIONS--When monitoring HIV infection one must take into account imported cases. HIV prevention efforts should be particularly focused at prostitutes from Latin America and at clients of prostitutes who migrated to the Netherlands.

Homosexual prostitution among male drug users and its risk for HIV infection.

OBJECTIVE--to assess whether male prostitution is an independent risk factor for HIV infection among male (intravenous and nonintravenous) drug users. DESIGN--a cross-sectional study. SETTING--various low-threshold methadone clinics and the sexually transmitted diseases clinic of the Municipal Health Service in Amsterdam and a drug-treatment centre in The Hague. PARTICIPANTS--343 male intravenous drug users and 106 male non-intravenous drug users. MAIN OUTCOME MEASURES--characteristics concerning drug use behaviour, sexual behaviour, and sociodemography, related to prostitution and HIV-antibodies. RESULTS--of the 449 study participants, 88 (20%) reported a history of prostitution; no differences were found between intravenous and non-intravenous drug users. Younger age, West German nationality, and having had private homosexual sex contacts, were independent predictors of a history of prostitution. Independent predictors of HIV infection were (1) longer residency in Amsterdam; (2) having had predominantly homosexual private sex contacts; (3) longer duration of intravenous drug use; and (4) frequent needle sharing. CONCLUSION--no evidence was found to suggest that male prostitution in itself contributed to the risk of HIV infection.