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.

Prevalence of hepatitis C virus infections among heterosexuals with multiple partners

A study among heterosexual men and women with multiple sexual partners was carried out to assess the seroprevalence of antibody against hepatitis C virus (HCV). The 468 participants were recruited among visitors to the Clinic for Sexually Transmitted Diseases in Amsterdam. Sera were tested by an enzyme-linked immunosorbent assay (ELISA; Ortho), a recombinant-based immunoblot assay (RIBA; Chiron), and the polymerase chain reaction (PCR). A total of 468 persons were tested, and seven (1.5%) were found ELISA positive. Another 25 (5%) were ELISA indeterminate. Six of the seven ELISA-positive cases were RIBA positive. Further serum samples from five HCV ELISA-positive persons were tested by PCR, and four were found to be positive. The HCV ELISA-positive/RIBA-indeterminate reaction was PCR negative. None of the 17 RIBA-tested sera of the ELISA-indeterminate group yielded a positive result. There was a good correlation between an ELISA optical density/cut-off ratio greater than 2 and a positive RIBA result. The risk factor for HCV appeared to be the type of sexual partner, i.e., belonging to a "high-risk" group for human immunodeficiency virus infection and origin from hepatitis B-endemic countries. It is concluded that HCV may be transmitted through heterosexual contact but probably with low efficiency.

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.

[Benefit of the serological screening program for syphilis in pregnant women in Amsterdam in the period 1985-1989]

The results of the serological syphilis screening programme for pregnant women in the region of Amsterdam in the period 1985-1989 are described. In addition, a cost-benefit analysis was done to determine useful effects of the programme. Every GP and obstetrician routinely takes blood samples from pregnant women to determine the blood group, rhesus factor and syphilis serology. In the period 1985-1989, a total of 37,520 serum samples were screened for syphilis in the Amsterdam region by the Central Laboratory of the Blood Transfusion Service (until mid-1986) and by the Regional Public Health Laboratory of the Municipal Health Service (from mid-1986). In 55 women (0.15%) both the Treponema pallidum haemagglutination assay (TPHA) and the venereal disease research laboratory (VDRL) tests were positive. Further evaluation of these 55 women ultimately brought to light 10 women with positive syphilis serology who had not been treated and consequently might infect their child with Treponema pallidum. Considering the various transmission percentages of the bacterium from mother to foetus, which depend on the stage of the maternal infection, the screening programme has prevented two cases of congenital syphilis. This brings the cost-benefit ratio of the syphilis screening programme for the region of Amsterdam to 1:6.2. In view of these findings there is no reason to reconsider the current screening practice in Amsterdam.

Risk of HIV infection among Dutch expatriates in sub-Saharan Africa

In order to study the prevalence of human immunodeficiency virus (HIV) infections and related risk factors, Dutch expatriates returning from sub-Saharan Africa were asked to complete a questionnaire on sexual, occupational and other risk factors, and to donate a sample of blood to test for antibodies against HIV. The 1968 participants were workers of various professions and their family members over 16 years of age posted in sub-Saharan African countries by Dutch governmental, non-governmental and commercial organizations for at least 6 months cumulative time between 1 January 1979 and 1 January 1990. Antibodies against HIV-1 were found among 4 of 1122 men (0.4%) and 1 of 846 women (0.1%). The woman and 3 of the men had had sexual contact with African partners and had been treated for sexually transmitted diseases, 2 of these 3 men also had an African life partner. One man reported occupational exposure only. Of the 1968 participants 89 men (7.9%) and 18 women (2.1%) lived with an African partner; 344 men (30.7%) and 111 women (13.1%) had heterosexual contact with other African partners. Only 22.3% (men) and 18.6% (women) of casual sexual contacts with African partners were always protected by a condom. Two hundred and thirty-two of 408 (56.9%) (para)medics reported needlesticks. Groups at risk of HIV infection through sexual exposure were identified using logistic regression models. In conclusion, the observed prevalence of HIV-1 is low. However, unprotected sexual contact with African partners and needlestick accidents were common. This study underscores the continuous need for health education of expatriates on the risks of transmission of HIV in Africa.

Trends in mortality among AIDS patients in Amsterdam, 1982-1988

In this study we evaluated the survival of 515 AIDS patients diagnosed in Amsterdam between 1982 and 1988 and followed-up until April 1990. Non-resident patients survived for a shorter period than resident patients (median survival time 10 versus 16 months). Residents had a 1-, 2- and 3-year survival of 56.1, 33.0 and 17.2%, respectively. Heterosexual intravenous drug users tended to have a better survival than homosexual men, although this was not significant. The survival time was longer for AIDS patients less than 30 years of age at diagnosis and varied for the different clinical manifestations leading to AIDS diagnosis. We calculated the 1- and 2-year survival probability by year of diagnosis for patients initially presenting with a Pneumocystis carinii pneumonia (PCP). The 1-year survival improved greatly in 1986 and continued to rise in the following years. The 2-year survival was similar in 1986 and 1987 (26.8 versus 28.2%) but increased in 1988 (38.9%). We conclude that besides better clinical experience and diagnostic methods, this improvement in prognosis could be explained by the start of secondary prophylaxis for PCP in 1985 and the introduction of zidovudine therapy in 1987.

Serum beta 2-microglobulin levels in asymptomatic HIV-1-infected subjects during long-term zidovudine treatment

beta 2-microglobulin levels were determined in the serum of 18 initially asymptomatic HIV-1 p24 antigenaemic subjects who were treated with zidovudine (+/- acyclovir) and who were followed for 2 1/2 years. The median serum beta 2-microglobulin level at week 0 was 2.5 mg/l and decreased to 2.3 mg/l after 12 weeks of treatment (p = 0.001). A correlation was found between individual changes in serum beta 2-microglobulin levels and individual changes in serum p24 antigen levels during the first 48 weeks of treatment (p less than 0.05). Six out of 18 subjects progressed to AIDS after 60-126 weeks of treatment. In this group during a period of more than one year before disease progression median serum beta 2-microglobulin levels increased from 2.5 mg/l to 3.3 mg/l (p = 0.03) and median CD4+ cell counts decreased from 0.3 x 10(9)/l to 0.08 x 10(9)/l (p = 0.03), while in that period the pattern of serum p24 antigen levels was inconsistent. Although the variability in serum beta 2-microglobulin levels appeared to make this marker unsuitable for management decisions in individuals, a decline in beta 2-microglobulin levels was found to parallel a decline in p24 antigen levels during the early phase of zidovudine treatment. Moreover, after prolonged treatment, rising beta 2-microglobulin levels--in contrast to p24 antigen levels--were shown to have predictive value for disease progression.

Low prevalence of human T-cell leukaemia 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.

Evidence for a change in behaviour among heterosexuals in Amsterdam under the influence of AIDS

In determining the effectiveness of AIDS preventive measures among heterosexuals, trends in visits to two clinics for sexually transmitted diseases (STD) in Amsterdam between 1982 and 1989 are described. Also, data on sexual behaviour are presented that were collected in a sample of 635 heterosexual women and 947 heterosexual men at one of the clinics between September 1986 and December 1988. In 1987, when in The Netherlands for the first time extensive publicity was given to the risk of heterosexual transmission of the human immunodeficiency virus, the numbers of male and female heterosexual attenders started to decline. Exceptions to this general decline were men of Turkish nationality and foreign prostitutes, each group showing a continuing increase. At the same time, the numbers of customers reported by prostitutes in the sample declined markedly between 1986 and 1988, from a median of 35 to 15 per month (p = 0.001). Condom use with casual contacts generally increased in the sample period. We conclude that the publicity given to "heterosexual AIDS"--contributed to by the national AIDS prevention campaign--apparently led to a considerable decrease in the number of risky contacts of heterosexuals in Amsterdam in 1987 and 1988. This does not seem to apply to men with Turkish nationality. In 1989 a change appeared in several subgroups when the number of visitors started to rise. Also, the probability of an STD diagnosis increased in male attenders. This may indicate a change in the tendency towards safer sexual behaviour.

[Relatively low HIV prevalence among drug users in The Hague in spite of risky injection behavior]

Between September 1987 and January 1989 101 drug users in The Hague were studied for HIV seroprevalence and risky injecting behaviour. A comparison was made between this group and a group of 241 drug users who were studied in the same period in Amsterdam. All HIV-infected drug users, except for one homosexual man in Amsterdam, had a history of intravenous drug use. The HIV seroprevalence for 56 intravenous drug users in The Hague was 1.8% (95% CI: 0-5.3), and for 194 intravenous drug users in Amsterdam 26.8% (95% CI: 20.6-33.0). With regard to risky injecting behaviour no differences in frequency of borrowing or lending used needles and syringes were found between the two groups. Concluded is that further spread of HIV among intravenous drug users in The Hague (and Amsterdam) will be likely unless risk reduction in injecting behaviour will occur.

Frequent injecting impairs lymphocyte reactivity in HIV-positive and HIV-negative drug users

To investigate whether drug use affected immunological parameters, we conducted a cross-sectional study of 321 drug users. Absolute numbers of CD4+ lymphocytes and the T-cell reactivity were lower in HIV-positive than in HIV-negative people. The functional capacity of the T-cell system as measured after stimulation with a monoclonal antibody directed against CD3 was found to be strongly associated with the frequency of injecting, while no relationship was found between the frequency of injecting and the total number of lymphocytes or T-cell subsets. HIV-negative and HIV-positive drug users who had injected a mean of three times a day in the preceding 4-6 months had a T-cell reactivity which was 40-50% lower compared with seronegative and with seropositive drug users who had not injected in the preceding months. We conclude that lymphocyte reactivity is depressed by frequent injecting in HIV-negative and HIV-positive drug users.

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.

Limited changes in sexual behaviour of heterosexual men and women with multiple partners in The Netherlands

To study changes in sexual behaviour, heterosexuals with multiple sexual partners were recruited through an STD-clinic and asked to return every 4 months for follow-up. Between October 1987 and June 1989, 512 heterosexuals entered the study and 140 men and 200 women had at least one follow-up visit. No changes were found between 3 visits in the kind of sexual techniques practiced. Condom use during vaginal intercourse with commercial partners (prostitutes or clients) was relatively high and remained high, but was low and remained at that level with private partners. Men and women reduced their number of private sexual partners by 50%, but the decline in the number of commercial partners was nonsignificant. Although more information is needed about the underlying social-psychological aspects of behavioural change, it seems necessary to redesign prevention activities to stress the effectiveness of condoms and to encourage condom use especially among heterosexuals with multiple private partners.

[Prognosis concerning HIV-infection and AIDS epidemic in The Netherlands based on mathematical analysis]

In the Netherlands by the 1st of January 1990 1074 AIDS patients have been reported to the Department of the Chief Medical Officer. In the last few years the proportion of intravenous drug users increased and the proportion of homo/bisexual men decreased. After adjustment for the effect of delay in reporting the total number of AIDS patients by 1st January 1990 is estimated to be 1173. It appears that the reporting delay outside Amsterdam is longer than in this city. The time required for doubling of the half-yearly incidence of new AIDS patients (doubling time, dt) increased from 9 months in the beginning of the epidemic to 34 months. It is expected on the assumption of constant dt that 1120 new AIDS patients will be diagnosed in 1990 and 1991 together. The present growth among the homo/bisexual men (dt 34 months) is smaller than the one among the intravenous drug users (dt 23 months). The growth in Amsterdam (dt 36 months) is less than that in the rest of the Netherlands (dt 32 months). Based on the course of the AIDS epidemic the number of HIV infected (including the AIDS patients) is estimated as 9,000-12,000 by the 1st of January 1990.

Prevalence of human T-cell leukemia virus antibody among heterosexuals living in Amsterdam, The Netherlands

To determine the heterosexual spread of human T-cell leukemia virus (HTLV-I) infections, a cohort of 472 individuals with more than 5 heterosexual partners in the 6 months before entry was studied. They were recruited from visitors to the Clinic for Sexually Transmitted Diseases of the Municipal Health Service. Half of the study group was born in the Netherlands, 13% in Surinam or the Dutch Antilles, and 8% in Turkey or Morocco. Seventy percent were involved in commercial sex. Three persons were positive for HTLV-I, with serum antibodies against p19, p24, p28, gp46, and gp61 in Western immunoblot (WIB) and radio-immunoprecipitation assay (RIPA). Two of them originated from Surinam and the third was a Dutch woman. Two other individuals were HIV-positive, 19% had hepatitis B virus (HBV)-markers and 6% Treponema pallidum reacted in the hemagglutination assay (TPHA). It is concluded that HTLV-I circulates in the Surinamese population in Amsterdam and there was no evidence of appreciable heterosexual transmission.

Herpes simplex virus type 2 and other genital ulcerative infections as a risk factor for HIV-1 acquisition

We studied the role of genital ulcerative infections for acquisition of human immunodeficiency virus type 1 (HIV-1) infection in a cohort of 989 homosexual men in Amsterdam between October 1984 and December 1988. Among 53 HIV-1 seroconverters serological and anamnestic data were gathered regarding herpes simplex virus type 2 (HSV-2) and syphilis in the 6 months before seroconversion. For statistical analysis a control who remained seronegative during the same interval was selected at random for each HIV-1 seroconverter. A significant difference between the prevalence of HSV-2 antibodies among HIV-1 seroconverters and controls was found (72% vs 38%). HSV-2 seroconversions among men initially seronegative for HSV-2 were found among three of 18 HIV-1 seroconverters and among three of 36 controls. (O.R. = 2.2, 95% C.I. 0.4-12.1). Self-reported cases of anogenital herpes were found more frequently among HIV-1 seroconverters (8) than among controls (4). One case of syphilis was diagnosed among HIV-1 seroconverters, and one among controls. Summing up these cases we assessed the total number of genital ulcerative infections: 12 among HIV-1 seroconverters and eight among controls (23 vs 15%, O.R. 1.7, C.I. 0.6-4.62). These data suggest little evidence for genital ulcerative infections being an important independent risk factor for HIV-1 acquisition among homosexual men in Amsterdam during the time period studied.

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.

[Analysis of antibodies against human immunodeficiency virus on a voluntary basis in healthy persons in Amsterdam 1988 and 1989]

At the Municipal Health Service of Amsterdam it is possible to be tested for HIV antibodies after signing an informed consent. In 1988, 1247 persons were tested (797 men, 450 women) and in 1989, 1400 persons (869 men, 531 women). Fifty-eight persons were identified as HIV-seropositive for the first time (1988: 24 men, 3 women; 1989: 28 men, 3 women). All but one woman belonged to a risk group or had had sexual contact with a person from a known risk group. In 1989 no increase in the percentage of HIV-seropositive persons was seen. In our (selected) group of persons in 1988 and 1989 we saw no transmission of HIV outside the known risk groups.

Risk factors and changes in sexual behavior in male homosexuals who seroconverted for human immunodeficiency virus antibodies

In Amsterdam, The Netherlands, a cohort of 982 homosexual and bisexual men has been studied since 1984. Of these, 238 men had antibodies to the human immunodeficiency virus at the onset of the study, and 84 men seroconverted while under study. For each of these seroconversions, two participants who remained seronegative were chosen for comparison, taking the seroconversion date as a reference. This offered an opportunity to study any changes that may have occurred longitudinally, i.e., over time. Risk factors for seroconversion were studied along with changes in sexual behavior relative to the moment of seroconversion. The number of different partners in anogenital receptive intercourse and a history of syphilis or anogenital herpes simplex were found to be predictors for human immunodeficiency virus seroconversion. The data suggest that, prior to seroconversion, there is a peak in riskful sexual behavior and that the "decline" often observed immediately after seroconversion is, in fact, an indication of a return to "normal" sexual activity.

Serum p24 antigen levels in untreated and zidovudine-treated HIV-1 infected subjects

HIV-1 p24 antigen levels were determined in sequential serum samples from 71 subjects with persistent p24 antigenaemia, obtained over a period of 6-36 months during which no antiretroviral treatment was given. Fifty-six subjects were initially symptom free: 39 remained so during follow-up and 17 developed AIDS. Fifteen subjects were studied from the moment AIDS was diagnosed. Median serum p24 levels rose in all groups. In 50/71 individuals, p24 levels rose with time; in 21 they declined. The mean change in p24 levels was +194%. Twelve of the symptom-free subjects were subsequently treated with 1000 mg zidovudine daily for 12 months, over which period p24 levels declined in all 12 (mean change -56%). The difference in number of subjects with rising and declining p24 antigen levels between the untreated and zidovudine treated group was significant (P less than 0.001). Triton X-100 pretreatment (which presumably enables detection of virion-associated p24 in addition to free p24) of serum samples from 2 subjects who seroconverted for p24 antigen, from 2 AIDS patients who did not receive antiretroviral treatment and from 2 zidovudine-treated symptom-free subjects, did not lead to a substantial increase in p24 levels, except in the case of one of the p24 antigen seroconverters. It is concluded that the decline in serum p24 levels reported to occur during treatment with putative antiretroviral drugs can largely be ascribed to this treatment.

Risk factors for progression of human immunodeficiency virus (HIV) infection among seroconverted and seropositive homosexual men

For identification of risk factors for progression of human immunodeficiency virus (HIV) infection, 746 homosexual men participating in a cohort study in Amsterdam, The Netherlands, were studied since October 1984. A total of 234 of these men were HIV antibody-positive at baseline, and 52 seroconverted during follow-up. These 286 individuals were categorized as high- and low-risk for progression to the acquired immunodeficiency syndrome (AIDS) on the basis of the presence or absence of HIV antigenemia, antibody to HIV core antigen, or a number of T helper lymphocytes less than 0.5 x 10(9)/liter during three or more subsequential blood samples. Ninety-six (41%) of the seropositives and 32 (62%) of those who seroconverted remained low-risk throughout the study period. Bivariate analyses revealed that educational level and a history of herpes zoster were associated with a low- and high-risk status, respectively. In multivariate analyses, a history of herpes zoster and a history of sexual intercourse with a person who had AIDS were associated with a more rapid disease progression. While herpes zoster is considered to be a marker of progressive immunodeficiency, a history of having sexual intercourse with a person who had AIDS points to the more virulent properties of HIV in these persons. Because both seropositives and seroconverters who had sexual intercourse with a person with AIDS had a more rapid disease progression, it seems plausible that being infected by a person with AIDS is a risk factor for a relative short incubation period.