Drug Users In Amsterdam Research Articles

HIV, sexually transmitted diseases and gynaecologic disorders in women

To determine the incidence of sexually transmitted diseases (STD; gonorrhoea, early syphilis, Chlamydia trachomatis infection, trichomoniasis and primary genital herpes) and gynaecologic disorders (vaginal candidiasis, anaerobic vaginosis, genital ulcerations of unknown cause, pelvic inflammatory disease, recurrent genital herpes, recurrent genital warts) in a cohort of HIV-infected and non-infected drug-using prostitutes in Amsterdam between 1986 and 1992. A subgroup of 212 female drug users with a history of prostitution, who made at least one visit to a special STD clinic for drug-using prostitutes was selected from an ongoing cohort study of drug users in Amsterdam. Using Poisson regression, the relative risk (RR) for each outcome was calculated for HIV-positive women compared with HIV-negative women. To determine potential causal relations with immune suppression, associations between disease incidence and immunologic markers (CD4 cell count and anti-CD3 response) were assessed in HIV-positive women. Adjusted for number of clients and frequency of condom use, HIV-positive women were at strong and significantly increased risk for primary genital herpes (RR, 7.64), recurrent herpes (RR, 8.33) and recurrent genital warts (RR, 15.93); moderately (significantly) increased risks were found for gonorrhoea (RR, 1.43), trichomoniasis (RR, 1.39), vaginal candidiasis (RR, 2.11) and genital ulcers of unknown aetiology (RR, 2.60). Of these HIV-related outcomes, the risk for recurrent genital herpes and genital warts were strongly associated with decreased CD4 cell counts. HIV-infected women experience an excess morbidity of STD and gynaecologic disorders. The strongly increased risk for genital herpes and warts in HIV-seropositive women indicates a causal relation with HIV. This study emphasizes the need for accessible medical care for drug-using prostitutes.

Injecting risk behavior among drug users in Amsterdam, 1986 to 1992, and its relationship to AIDS prevention programs.

Serial, cross-sectional trends in injecting risk behavior were studied among drug users from 1986 to 1992. From a cohort study in Amsterdam, 616 intake visits of drug users who had injected in the 6 months preceding intake were selected. The proportion of drug users who reported borrowing and lending used injection equipment and reusing needles/syringes (in the previous 6 months), continuously declined from 51% to 20%, from 46% to 10% and from 63% to 39%, respectively. In multivariate analysis, it appeared unlikely that a selective recruitment of participants over time was responsible for these trends. Participants, recruited later in time, had been previously tested for human immunodeficiency virus (HIV) more often, had received daily methadone less often, and had obtained a higher proportion of new needles via exchange programs. Indications were found that (1) voluntary HIV testing and counseling leads to less borrowing, lending, and reusing equipment; and (2) obtaining needles via exchange programs leads to less reusing needles/syringes. It appeared that nonattenders of methadone and exchange programs have reduced borrowing and lending to the same extent as attenders. Methodologically, evaluating specific measures is difficult. However, the combination of various preventive measures in Amsterdam is likely to be responsible for the observed decrease in injecting risk behavior.

A longitudinal study on the incidence and transmission patterns of HIV, HBV and HCV infection among drug users in Amsterdam

In the present study data on the incidence of HBV and HCV were used to indicate the prevalence of and trends in risk behavior, assuming that drug users (DUs) who become infected with HBV or HCV are also at risk for infection with HIV. In addition, we determined to that extent the transmission patterns of HIV, HBV and HCV differed. DUs were selected from a cohort study in Amsterdam, had at least one follow-up visit between December 1985 and September 1989 and reported never to have had homosexual contacts. Among 305 DUs, of whom 70% injected recently, the prevalence of HIV, HBV and HCV were 31%, 68% and 65% respectively. These prevalences were strongly interrelated and the same risk factors were found. The cumulative incidence of either HIV or HBV or HCV was 30% among prevalent HIV-negatives. Despite a previously reported reduction in risk behavior, only the HIV incidence tended to decrease initially, and after 1986 the incidences of HIV, HBV and HCV remained disturbingly high and stable (mean: 4, 9 and 10 per 100 person-years, respectively). As at present HBV appears to be transmitted more heterosexually than HIV in our study group and the HIV-epidemic may follow the HBV-epidemic in its transmission patterns, preventive activities targeted at both injecting and sexual behavior should be expanded.

HIV Risk Behavior and Beliefs of HIV-Seropositive Drug Users

To assess HIV risk behavior, beliefs, attitudes and intentions among HIV-seropositive drug users (DUs), we studied 122 HIV-positive DUs (including ninety-five current injectors) participating in a longitudinal HIV-study among DUs in Amsterdam. All were familiar with their serostatus. Over a period of four months, 20% of the sample put others at risk of HIV infection, mainly through unsafe sex. Forty-nine percent think they might infect someone with HIV in the future, again mainly through unsafe sex. Although the majority intends to use condoms, self-efficacy and response efficacy is low; that is, many do not think they are able to use condoms when necessary and many have limited confidence in the efficacy of condoms in preventing HIV transmission. Correlates of HIV risk behavior were non-Dutch nationality and being a female prostitute. The results suggest that, next to efforts which aim to prevent new infections among HIV-negative injectors or sexual partners of injectors, prevention efforts should focus on HIV-seropositive DUs or former DUs.

The Harm Reduction Approach and Risk Factors for Human Immunodeficiency Virus (HIV) Seroconversion in Injecting Drug Users, Amsterdam

To assess risk factors for seroconversion to human immunodeficiency virus, the authors studied a cohort of human immunodeficiency virus-seronegative injecting drug users in Amsterdam, the Netherlands, between December 1985 and November 1991. The behaviors of 31 seroconverters were compared with those of 202 seronegative injecting drug users (controls). Three independent risk factors for seroconversion were found in logistic regression: 1) living greater than 10 years in Amsterdam (odds ratio (OR) = 2.45, 95% confidence interval (CI) 1.09-5.53); 2) first injection less than or equal to 2 years ago (OR = 3.43, 95% CI 1.20-9.81); and 3) injecting mainly at home (OR = 0.39, 95% CI 0.18-0.88). No evidence was found that receiving daily methadone treatments at methadone posts and obtaining new needles/syringes via the exchange program were protective. However, the data suggest that exchanging needles may have been protective at the start of this program. Influencing injecting drug users to modify behavior to prevent new infections appears to be very difficult, and it may, therefore, be important to increase preventive efforts targeted at the sexual partners of injecting drug users.

Little Change in Sexual Behavior in Injecting Drug Users in Amsterdam

To assess heterosexual behavior of injecting drug users (IDUs) over time, we studied 174 IDUs with regard to their steady, casual, and commercial partners over a 1-year period. Within this year a large national AIDS prevention campaign had been implemented in the Netherlands. In addition, condom use was discussed with participants during various follow-up visits. We found a large turnover in IDUs who reported having steady, casual, or commercial partners. Limited change in sexual behavior occurred: the frequent use of condoms increased only with casual partners (from 30 to 49%), and the proportion of female IDUs working as prostitutes decreased (from 56 to 41%). At both measurements IDUs who knew that they were HIV infected used condoms more frequently with their steady partners and tended to report fewer casual partners than those who knew they were not infected. In addition, HIV-infected women tended to be less active in prostitution than noninfected women. We conclude that large-scale voluntary testing of IDUs, together with repeatedly discussing the risks of sexual transmission of HIV and the use of condoms as a preventive measure (counseling) may, at least among HIV-infected IDUs, result in some risk reduction. Health education to increase the use of condoms should also be directed at IDUs who at present do not have steady, casual, or commercial partners.

Increasing morbidity without rise in non-AIDS mortality among HIV-infected intravenous drug users in Amsterdam.

We determined pneumonia, endocarditis, hospitalizations and death rates in a group of HIV-infected and non-infected IVDU recruited at low-threshold methadone programmes in Amsterdam, The Netherlands to examine the influence of HIV infection on morbidity and non-AIDS mortality in intravenous drug users (IVDU) without AIDS. A prospective epidemiologic study among HIV-infected and non-infected IVDU in Amsterdam. We analysed patients attending the Municipal Health Service of Amsterdam. The patient group consisted of 197 HIV-seropositive IVDU and 193 HIV-seronegative IVDU as controls. We analysed incidence rates per person-year of bacterial pneumonia; hospitalizations and non-AIDS mortality; and relative risks for HIV-infected IVDU compared to non-infected IVDU. The incidence of bacterial pneumonia rose from 0.1 in 1986 to 0.29 in 1989 in HIV-infected IVDU. The overall relative risk for this group was 4.0 (95% confidence interval, 1.7-9.7) compared with non-infected controls. HIV-infected IVDU were more frequently hospitalized for bacterial pneumonia than non-infected IVDU (50 versus 13%). In contrast, non-AIDS mortality rates remained stable for both HIV-infected and non-infected IVDU. HIV seropositivity was not found to be an independent risk factor for non-AIDS mortality. We found a high and rising incidence of bacterial pneumonia among HIV-infected IVDU in Amsterdam without any consequential rise in non-AIDS mortality. This contrasts with reports from studies conducted in New York City, New York, USA, where bacterial pneumonia-related mortality has been found to increase markedly, coincident with the AIDS epidemic. Early detection of bacterial pneumonia and easy access to both inpatient and outpatient medical care may be important factors in preventing early death due to common bacterial pathogens in IVDU without AIDS.

Changes over time in heroin and cocaine use among injecting drug users in Amsterdam, The Netherlands, 1985–1989

Three hundred and eighty six injecting drug users entered into an HIV study through methadone programs over a 40 month period. Differences in oral, intranasal and parenteral use of heroin and cocaine were assessed between four consecutive 10 month intake groups. Heroin smoking and cocaine freebasing were increased in the later intake groups, while there were no significant changes in injecting variables. No relationship between sexual risk behaviour and cocaine freebasing was found. HIV seropositivity was less among cocaine freebasers at 19% compared to 32% among non freebasers. The increase in heroin smoking and cocaine freebasing may have a favourable preventive effect on the spread of HIV among this high risk group.

Low prevalence of human T‐cell leukemia virus‐I and ‐II infection among drug users in Amsterdam, the Netherlands

The prevalence of human T-cell leukaemia virus-I and -II infection was studied in a cohort of 346 intravenous and nonintravenous drug users in Amsterdam. Three participants (0.86%) had antibodies to HTLV-I by two commercially available HTLV-I enzyme immunoassays (EIA). Infection in these three subjects was confirmed by radioimmunoprecipitation assay. In the immunoblot study, only two of the three subjects were considered positive, since the serum of the third subject had antibodies to p24 only. By means of the polymerase chain reaction two participants (male intravenous drug users infected with human immunodeficiency virus; HIV) appeared to be infected with HTLV-I and one subject (a male nonintravenous drug user from Surinam) with HTLV-II. It is concluded that HTLV-I and HTLV-II circulate sporadically among drug users in Amsterdam and that risky injecting behaviour, which led to an HIV epidemic among intravenous drug users, has not led so far to an appreciable transmission of the other retroviruses among this group.

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.

Prevalence, Incidence, and Risk Factors of Hepatitis C Virus Infection among Drug Users in Amsterdam

The prevalence, risk factors, and incidence of hepatitis C virus (HCV) infection were studied in a cohort of drug users in Amsterdam. In intravenous drug users, the seroprevalence was 74% (224/304) versus 10% (4/42) in nonintravenous drug users. Risk factors independently associated with HCV antibody seropositivity were history and duration of intravenous drug use and frequency of injections. Daily smoking of heroin in the previous 6 months was independently associated with the absence of HCV antibodies. Periods of fever, tiredness, and diarrhea in the preceding 6 months were associated with HCV antibodies even after correction for human immunodeficiency virus infection. The incidence rate of HCV infection appeared high and stable over the years 1986 to 1989. Thus, HCV infections are common among intravenous drug users and are mainly due to the intravenous use of drugs.

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.