Differences in clinical manifestations of genital chlamydial infections related to serovars

OBJECTIVES

To study the association of serovars of Chlamydia trachomatis with clinical manifestations of genital tract infection and socio-demographic characteristics.

METHODS

In 1986-88 the C trachomatis isolates from 159 heterosexual men and 116 women attending a sexually transmitted disease (STD) clinic were collected and typed accordingly. A medical history was recorded, a physical examination took place and samples were taken for laboratory diagnostics.

RESULTS

Serovars E, F and D were the most common for both men (75%) and women (67%). Men infected with serovars of the C-complex had more often a history of STD (p = 0.06). The opposite was demonstrated in women (p = 0.07). In addition, women younger than 18 years at first intercourse were more often infected with C-complex serovars (p = 0.05). For men, the serovars F/G less often produced symptoms of urethral discharge (p = 0.01) than the serovars of the B-complex and C-complex and were less often associated with the presence of 10 or more leukocytes in a Gram-stained smear (p = 0.04).

CONCLUSIONS

In this study, infections with serovars F and G caused less obvious symptoms and signs of inflammation in men; in women no differences were found in the clinical manifestation of infections with different serovars.

Incidence and risk factors for pneumonia in HIV infected and non-infected drug users

OBJECTIVE

To study the incidence and risk factors for pneumonia in a cohort of HIV infected and non-infected drug users (DU).

DESIGN

A prospective epidemiological study.

SETTING AND PATIENTS

Injecting and non-injecting DU who attended the Municipal Health Service in Amsterdam for follow-up visits in the study.

MAIN RESULTS

203 HIV infected and 437 non-infected DU were followed for a total of 1749 person-years. HIV infected DU reported 111 episodes of pneumonia, which required hospitalization in 29 cases, and HIV negative DU reported 55 episodes, which required hospitalization in nine cases. The incidences among HIV positive and HIV negative DU were 0.19 and 0.05 per person-year respectively. With multivariate Poisson regression current injecting (RR 2.13), recent seroconversion (RR 3.92), asthmatic constitution (RR 2.72), CD4+ cell count between 200-500 (RR 1.67 compared to > 500), CD4+ cell count less than 200 (RR 2.23 compared to > 500) and a previous history of pneumonia (RR 2.43) were independently associated with self-reported pneumonia among HIV infected DU. Among HIV negative DU heroin smoking (RR 1.87), asthmatic constitution (RR 3.62) and a previous history of pneumonia (RR 2.84) were independently associated with self-reported pneumonia. Also a higher Quetelet Index (QI) appeared to be protective (QI > or = 21 RR 0.42, QI 19-21 RR 0.82 compared to QI < 19) among HIV negative DU. Risk factors for reported and hospitalized cases of pneumonia were comparable among HIV positive DU.

CONCLUSIONS

HIV infected DU are at increased risk for pneumonia and the rate increases with lower CD4 cell counts. Also behavioural characteristics, such as injecting drug use and smoking heroin, and clinical history variables, such as a history of pneumonia or an asthmatic constitution, are risk factors for pneumonia among DU. Pneumococcal vaccination should not only be focused on HIV positive DU but also on the identified risk groups among HIV negative DU.

Euthanasia and physician-assisted suicide in homosexual men with AIDS

BACKGROUND

In the Netherlands a nationwide study has shown that, in 38% of deaths, there have been medical decisions concerning the end of life (MDEL); 2.1% of all deaths were brought about by euthanasia or physician- assisted suicide (PAS). We investigated the incidence of MDEL in homosexual men with AIDS, suspecting that it might be higher, and studied the effect of euthanasia/PAS on survival time.

METHODS

The patients were 131 male homosexual participants in a cohort study in Amsterdam, diagnosed between 1985 and 1992 as having AIDS; all had died before Jan 1, 1995. Clinical and laboratory data and information on mode of death were obtained from their physicians and by review of hospital records. Those who died by euthanasia/PAS or in whom there had been other MDEL were then compared with those who died naturally.

FINDINGS

29 men (22%) had died by euthanasia/PAS and in 17 (13%) another MDEL had been made; thus, more than one-third of these men had made medical decisions concerning the end of life. The greatest difference between the groups was in age at time of diagnosis-72% aged 40 or more in the euthanasia/PAS group compared with 38% in the natural death group. The likelihood (relative risk) of euthanasia/PAS increased with duration of survival after AIDS diagnosis. Comparison of the groups in terms of three laboratory markers (CD4+ and CD8+ cells and phytohaemagglutinin responses) in the two years before death, and estimates of these markers at the time of death, did not indicate any substantial shortening of life by euthanasia/PAS; in the judgment of the physicians, most of these patients would have died naturally within one month.

INTERPRETATION

A possible reason for the high incidence of MDEL in this cohort was a good knowledge of the characteristics of AIDS acquired through long-term awareness of HIV infection. The higher rate of euthanasia in those with long survival from AIDS diagnosis could reflect either additional suffering or the greater opportunity to discuss this option with friends and physicians. Our findings indicate that euthanasia and other MDEL did little to shorten life; rather, they were an extreme form of palliation, applied in the terminal phase of a lethal disease.

Predictors of mortality in the Amsterdam cohort of human immunodeficiency virus (HIV)-positive and HIV-negative drug users

The impact of human immunodeficiency virus (HIV) infection and other risk factors on mortality was studied in a cohort of Dutch injection drug users and drug users who did not inject. Participants were recruited between 1985 and 1992 and followed up through 1993. Vital status was ascertained through repeat visit information, supplemented by population register data. A total of 77 deaths were recorded among 632 drug users, for a mortality rate per 1,000 person-years of 7 for HIV-negative noninjection drug users, 18 for HIV-negative injection drug users, and 64 for HIV-positive injection drug users. In multivariate analyses, limited to injection drug users, a positive HIV serostatus, age above 40 years, and using benzodiazepines several times daily were significantly associated with an elevated risk of death, both for death from all causes and for death preceding acquired immunodeficiency syndrome (AIDS) diagnosis (pre-AIDS). For pre-AIDS death, the adjusted relative risk associated with HIV infection was 2.2 (95% confidence interval 1.3-3.7). Only 38% of HIV-infected injection drug users who died were diagnosed with AIDS. However, 76% of HIV-infected injection drug users who died without AIDS diagnosis had evidence of immunosuppression (CD4 count < 500/microliters). Daily use of methadone and participation in needle and syringe exchange schemes were not associated with lower mortality rates. This study illustrates in a group of injection drug users with a 30% HIV seroprevalence and a high background mortality the profound influence on mortality that HIV infection has gained.

Development and evaluation of screening strategies for Chlamydia trachomatis infections in an STD clinic

OBJECTIVES

To identify predictors for Chlamydia trachomatis infection among visitors of an STD clinic in Amsterdam in 1986-1988. To design predictor-based screening programmes for C trachomatis. To evaluate the chosen screening strategy in 1993.

METHODS

In 1986-1988, 947 heterosexual men and 648 women participated in the study. A medical history was recorded, a physical examination took place and samples were taken for laboratory diagnostics. Information for 1993 was available from routine databases.

RESULTS

C trachomatis infections in heterosexual men in 1986-1988 (prevalence 15.8%) were independently associated with: age under 26 years, being an STD contact, coitarche below 13, last sexual contact with a non-prostitute, (muco)-purulent urethral discharge and ten or more leukocytes per microscopic field of urethral smear or urine. For women (prevalence 21.5%) independent predictors were age under 26, no history of STD, being an STD contact, cervical friability, (muco)purulent cervical discharge, presence of clue cells and ten or more leukocytes per field of urethral smear. Screening men with one anamnestic predictor for C trachomatis and ten or more leukocytes in smear or urine (59% of men) would detect 93% of the cases in 1986-1988. For females only universal screening proved to be suitable. After the introduction of a screening strategy in 1989 (universal for women, indicated by urethritis for men), a strong decline was found in the C trachomatis prevalence for all subgroups in 1993, excluding prostitute's clients and Turkish men.

CONCLUSIONS

In 1993 the overall C trachomatis prevalence had declined among the attendants of the STD clinic. It seems likely that this fall was caused both by the screening programme and the reduction of risk behaviour.

Validity of self-reported sexually transmitted diseases in a cohort of drug-using prostitutes in Amsterdam: trends from 1986 to 1992

BACKGROUND

Rates of self-reported sexually transmitted diseases (STD) among drug-using prostitutes in Amsterdam have been shown to be declining. However, self reports may provide biased estimates.

METHODS

We determined the prevalence of risk indicators for and time trends in incorrect self-reported STD in a cohort of drug-using prostitutes. Rates of self-reported STD were validated with diagnosed STD from a special STD clinic for drug-using prostitutes.

RESULTS

Between 1986 and 1992, 314 STD were diagnosed in 85 (65%) of 131 studied prostitutes. Overall, 34% of diagnosed STD was not reported in the cohort, referred to as underreporting. For 40% of reported STD, no diagnosis was obtained ('overreporting'). In spite of these misclassifications, absolute numbers of reported and diagnosed STD practically balanced. Underreporting was independently associated with longer residence in Amsterdam (OR = 2.34 per 5 years), more than six clinic visits between two cohort visits (OR = 0.31), daily use of non-parenteral drug (OR = 8.45) and mainly injecting heroin (OR = 6.93); overreporting was independently associated only with a lower frequency of clinic visits. Multivariate analyses showed that trends in underreporting and overreporting were in part explained by a higher number of visits in the cohort and by lower numbers of clinic visits between two cohort visits.

CONCLUSIONS

Self-reporting of STD in our cohort is unreliable and misclassification prevalent; risk factors for and associates of self-reported STD are biased. Inferences drawn from self reports are potentially misleading and therefore such data need to be validated. Trends in misclassification can be interpreted as recall errors and as a study participation effect. For monitoring of STD prevalences in relation to trends in sexual risk behaviours, diagnosed STD should be used in preference to self reports.

[HIV surveillance in an outpatient clinic for sexually transmissible diseases in Amsterdam, 1991-1994; low and stable prevalence among heterosexual clients]

OBJECTIVE

To assess the HIV prevalence among heterosexual attenders of a clinic for sexually transmitted diseases (STD) and among subpopulations, including young gay men and ethnic minorities.

SETTING

Outpatient clinic for sexually transmitted diseases (STD) of the Municipal Health Service of Amsterdam, the Netherlands.

METHODS

Semi-annually in the period 1991-1994, blood samples given voluntarily and anonymously were tested for HIV antibodies and some characteristics were collected of approximately 1000 clinic attenders.

RESULTS

Since 1991, 6766 clinic attenders were eligible for participation, of whom 6200 (92%) were actually tested. The overall HIV prevalence decreased from 3.9% in the first half of 1991 to 2.3% in the second half of 1994. Among heterosexual clinic attenders the prevalence remained stable below 1%, due mainly to visitors from abroad rather than to Dutch heterosexuals: 20 of the 23 HIV infected heterosexuals were not Dutch. None of these 23 seropositive persons knew of their HIV infection, mostly because they had not been tested previously. The HIV prevalence among gay men decreased over the years. In addition, the number of gay male attenders younger than 30 years decreased strongly over time.

CONCLUSIONS

HIV infections among heterosexual STD clinic attenders are relatively few and are seen mainly among non-Dutch. We found no indications of an increase of the HIV prevalence among heterosexual clinic attenders. The results among young gay men are suggestive of a shift towards safer sexual behaviour in this group.

The predictive value of T cell function in vitro and pre-AIDS zidovudine use for survival after AIDS diagnosis in a cohort of homosexual men in Amsterdam

The best independent predictors of survival after AIDS diagnosis were determined in 160 homosexual men from the Amsterdam Cohort Study (1987 CDC case definition). In a Cox model, all pre-AIDS laboratory markers gathered during follow-up in the study did not independently predict survival after AIDS. A second analysis, using data available only at AIDS diagnosis, revealed that T cell reactivity after stimulation with phytohemagglutinin and monoclonal CD3 antibodies and the CD4+ cell count at diagnosis were independent predictors of survival. In an interval-based Cox model, the predictive value of pre-AIDS zidovudine use was determined. One year after AIDS diagnosis, participants with pre-AIDS zidovudine use had a worse survival probability (relative hazard = 3.99). In conclusion, the survival probability of homosexual men with AIDS can be estimate adequately using information obtained at clinical AIDS diagnosis. Analysis revealed the important predictive value of T cell function tests in vitro.

Determinants of penicillinase producing Neisseria gonorrhoeae infections in heterosexuals in Amsterdam

BACKGROUND AND OBJECTIVES

At the STD clinic of the Municipal Health Service in Amsterdam, the annual number of infections with penicillinase-producing Neisseria gonorrhoeae (PPNG) strains remained relatively stable from 1983 until 1990, while the number of non-PPNG infections declined dramatically. To investigate the PPNG and non-PPNG epidemic, a cross sectional study was conducted in 1989 and 1990. The purpose of this study was to assess determinants of PPNG infections among heterosexuals diagnosed with gonorrhoeae.

METHODS

In addition to routinely collected data in new consultations for STDs, information on alcohol use, drug use and sexual behaviour was obtained from patients diagnosed with gonorrhoea. The diagnosis of gonorrhoea was based on a positive culture and isolates were screened for PPNG. Logistic regression analysis was used to assess independent predictors of PPNG infection.

RESULTS

Additional information was available of 328 women and 995 heterosexual men diagnosed with gonorrhoea. PPNG was diagnosed in 86/328 (26%) women and in 329/995 (33%) men. Logistic regression analysis identified a Central/South American nationality (odds ratio(OR) = 2.46) and older age (OR = 1.04 per year) as positively associated with PPNG infection in female patients. An inverse relation was found with use of hard drugs (OR = 0.29). Among men diagnosed with gonorrhoea, sexual contacts with window prostitutes (mainly women from Central/South America) (OR = 1.98) and a foreign nationality (OR = 1.78) were positively associated with PPNG infection, and sexual contact with drug using prostitutes (OR = 0.47) inversely.

CONCLUSIONS

PPNG infections were especially common among Central and South American window prostitutes and their clients, but not among hard-drug addicted prostitutes and their clients. Since window prostitutes originating from Central and South American countries are transient in Amsterdam, prevention activities targeted at these prostitutes and their clients should be continued to limit the spread of PPNG and other STDs within these groups.

Regional distribution and incidence of human papillomavirus infections among heterosexual men and women with multiple sexual partners: a prospective study

OBJECTIVE

To assess prevalence, incidence and potential risk factors of human papillomavirus (HPV) infection among heterosexual men and women with multiple partners and to identify niches of HPV-infection.

DESIGN

A prospective study of heterosexual men and women with multiple partners attending an STD clinic as participants in a study on HIV from May 1988 until January 1991. Routine STD examination and physical examination using colposcopy were performed, interviews with standardised questionnaires were administered. Specimens for HPV DNA detection by polymerase chain reaction were collected from multiple sites of the genital, anorectal and oral regions. In women cervical cytology was performed.

SETTING

The STD Clinic of the Municipal Health Service of Amsterdam.

PARTICIPANTS

162 women and 85 men entered the study, 110 women and 48 men were followed up.

RESULTS

At entry of the study 37 (23%) women and 24 (28%) men were found positive for HPV DNA at any site. Only in one woman was oral presence of HPV DNA found during follow-up. Abnormal cervical cytology was observed in four women. In multivariate analysis, diagnosis of condylomata [odds ratio (OR) 5.61, 95% confidence interval (CI) 1.86 to 16.90)], reporting genital dermatological abnormalities (OR 3.72, 95% CI 1.38 to 9.99) and age (OR per year 0.93, 95% CI 0.88 to 0.99) predicted independently the presence of HPV DNA in women at entry of the study. In women 59 of the 99 (60%) HPV infections were observed in the genital region and 40% in the anorectal region: in men these figures were 65% and 35%, respectively. The incidence of HPV infection was 47.1 and 50.5 per 100 person-years for women and men respectively. At least 20/99 (20%) infections in women were intermediate or long persistent and only 3/48 (6%) HPV infections in men (P = 0.03). No risk factor for persistency could be determined, either in women or in men.

CONCLUSIONS

HPV infection was found to be a multicentric genital and/or anorectal event both in women and men. The oral presence of HPV DNA was detected only once in one of the participants. In women persistent HPV infection was more common than in men. Independent predictors for presence of HPV DNA in women were diagnosis of condylomata acuminata, reporting genital dermatologic abnormalities and age. Incidence of HPV infection in women turned out to be 47.1 infections per 100 person-years and for men 50.5 per 100 person-years.

Risk factors for the transition from noninjection to injection drug use and accompanying AIDS risk behavior in a cohort of drug users

Although injection drug users have been shown to reduce high-risk injection behaviors in response to the epidemic of human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS), the total elimination of risk behaviors has not been achieved. A more fundamental preventive measure may be to keep drug users from starting to inject at all. The authors selected 184 drug users from a cohort study in Amsterdam, the Netherlands, from 1985 to 1992, who had reported at entry to the study that they either had never injected drugs or had injected for the last time more than 1 year before the initial visit. Over a 5-year follow-up period, impressively high cumulative rates of transition to injection drug use were found in both groups. Among drug users who had never injected drugs, 30% began injecting; among those who had injected drugs 1-5 years before their entry into the study, 70% started injecting again. These rates were stable over time. The authors also confirmed that new injectors are at high risk of acquisition of HIV infection. With the use of a survival and a nested case-control analysis, the following independent risk factors that increased the likelihood of starting to inject were found: previous injecting history, ethnicity other than Surinamese/Antillean, regular long-term use of cocaine, current use of heroin, and a current steady sexual relationship with a partner who injects drugs. Given the high and stable incidence of initiation of injection among drug users within the cohort study, the prevention of this behavior appears to be difficult. Additional studies are needed to determine effective prevention strategies.

Enzyme immunoassay with enhanced specificity for detection of antibodies to Chlamydia trachomatis

Two different methods for preventing the binding of cross-reacting antibodies to the genus-reactive chlamydial lipopolysaccharide (LPS) were used to improve the specificity of an enzyme immunoassay for the determination of antibodies to Chlamydia trachomatis. Coated elementary bodies were treated with either sodium periodate, to oxidize the antigenic sites of the LPS, or Triton X-100, to extract the LPS. By using these new enzyme immunoassays, the standard enzyme immunoassay, and the whole inclusion fluorescence (WIF) assay, antibodies to C. trachomatis were determined in sera from different groups of patients and controls. Paired serum samples from patients with culture-proven urogenital C. trachomatis infections showed similar responses in all three assays. Paired serum samples from patients with Chlamydia psittaci infections showed similar responses in the WIF assay and the standard enzyme immunoassay, whereas significantly reduced titers were obtained in the enzyme immunoassays with treated antigen, especially in the convalescent-phase serum samples. Serum samples from patients with symptoms suggestive of infection with C. trachomatis, pregnant women, and blood donors were evaluated by all three types of assays. Eighty percent of the significant reductions in immunoglobulin G (IgG), IgA, and IgM titers were observed in sera with WIF assay titers in the lower classes (IgG, 1: < or = 256; IgA, 1: < or = 32; IgM, 1: < or = 16). From these results we conclude that oxidation of the antigen by sodium periodate is a simple and effective method of producing an enzyme immunoassay with enhanced specificity that could be useful for diagnostic purposes and seroepidemiological studies.

[Survival of patients following the diagnosis of AIDS in the Amsterdam region, 1982-1991]

OBJECTIVE

To evaluate the survival of 975 AIDS patients diagnosed in the Amsterdam region between 1982 and 1991, with follow-up until December 31st, 1992.

METHODS

Analysis of data from the active AIDS surveillance system for the Amsterdam region at the Municipal Health Service.

RESULTS

Amsterdam region residents had 1, 2 and 3-year survivals of 69.8%, 42.6% and 21.2%, respectively. The 5-year survival was 7.7%. The median survival probability for all patients showed great improvement, from 9 months in 1982-1985 to 26 months in 1990. For patients initially presenting with only Pneumocystis carinii pneumonia (PCP) the greatest improvement occurred between the period 1982-1985 and the year 1986. For patients without PCP the most important improvement occurred one year later. From 1988 onwards no important improvement in the 1-year survival is noticed. The 2-year survival, however, appears still to be increasing. In a Cox proportional hazards model the following variables were found to be independent predictors for survival: age at diagnosis, earliest clinical AIDS manifestations, year of diagnosis and HIV risk group. No differences were seen in the 1 and 2-year survival probabilities for men and women with AIDS. Heterosexual men and women tended to have a poorer survival than intravenous drug users and homosexual and bisexual men.

CONCLUSION

A noticeable improvement in the survival probability with time occurred for AIDS patients living in the Amsterdam region through the years 1982-1991, although the overall survival after AIDS diagnosis is still poor. The 1-year survival appears to have reached a plateau, the 2-year survival is still increasing. Improved clinical experience, awareness of HIV related complaints in high risk groups, better diagnostic methods and the availability of proper medication (prophylactic and treatment) are the most likely explanations of the improvement in survival.

Do bisexual men play a significant role in the heterosexual spread of HIV?

BACKGROUND AND OBJECTIVES

To assess the potential role of bisexual men in the transmission of HIV to women.

STUDY DESIGN

The study population consisted of homosexual men participating in a longitudinal cohort study on HIV and AIDS in Amsterdam, the Netherlands, which started in 1984. Between April and November 1991, an additional questionnaire was administered concerning sexual behavior with both male and female partners in the last 6 months.

RESULTS

Of these men, 27% described their sexual preference as bisexual or heterosexual. In the last 6 months, 23 (3%) had heterosexual contacts. Vaginal intercourse was the sexual technique most practiced. Anal intercourse with a female partner was rare. Four heterosexual active HIV positive men always used condoms when having heterosexual contact (1 missing). Of the 18 heterosexually active HIV seronegative men, 12 did not use condoms consistently with their female partner(s). Two of these 12 men also had unprotected insertive anogenital intercourse with male partners, which conveys a small transmission risk in the window period in the case of a seroconversion.

CONCLUSION

Widespread transmission of HIV from these homosexual men in this study is not likely. However, the studied men are most probably not representative for homosexual men in Amsterdam, the Netherlands. Further study on the potential role that bisexual men play in the HIV transmission to women is therefore needed.

[HIV infection and unsafe sexual behavior among young homosexual men in Amsterdam, 1992]

OBJECTIVE

To determine the prevalence of sexual behaviour with the risk of HIV transmission among young homosexual men in Amsterdam.

DESIGN

Point prevalence study.

SETTING

Amsterdam.

METHODS

Participants were recruited through advertisements and in gay bars and a STD clinic in the period October 1991-1992. A questionnaire regarding sexual behaviour was completed, and blood samples were drawn to test for presence of serological markers of HIV infection, hepatitis B and syphilis.

RESULTS

Enrolled in the study were 154 men (mean age: 25 years). The prevalence of antibodies against HIV was 5% and that of hepatitis B 22%. Receptive anogenital intercourse with steady partners in the previous six months was reported by 60% (74% sometimes without a condom), with non-steady partners by 41% (40% without a condom). The figures for insertive anogenital intercourse were: steady partners: 45% (74%); non-steady partners: 49% (41%). Overall 43% (66/153) reported at least one unprotected anogenital contact in the previous six months. The presence of HIV antibodies was correlated with the number of partners with whom anogenital sexual intercourse was practised.

CONCLUSION

The HIV prevalence (5%) was relatively low. Considering the high prevalence of unsafe sexual behaviour further spread of HIV infection among young homosexual men is to be expected.

[HIV prevalence among Surinam and Antillean drug users in Amsterdam]

OBJECTIVE

To determine the HIV prevalence and the frequency of injecting drugs among drug users from Surinam and the Netherlands Antilles in Amsterdam.

DESIGN

Descriptive study.

SETTING

Amsterdam streets.

METHOD

Participants were recruited in 1992 in the street and interviewed about their drug use behaviour, sexual life style and previous HIV test results. Blood or saliva samples were collected for HIV antibody testing.

RESULTS

Of 198 participants recruited, 185 (93%) were males. The mean age was 38 years. The mean duration of stay in the Netherlands was 19 years and mean duration of drug use 14 years. Sixty-eight percent of the participants received methadone treatment. Injecting drugs at any time was reported by 29 (15%) participants. Injecting drug users (IDU) more often had a steady partner who also injected or otherwise used drugs. Nearly one-quarter reported having had sex with a steady or casual IDU partner. HIV prevalence among IDU was 17% (5/29; 95%-CI 7.4-35%), among heterosexual male non-IDU 4.5% (7/156; 95%-CI 2.1-9.1%) and among female non-IDU 9.1% (1/11; 95%-CI 1.3-44%). HIV positive heterosexual non-IDU reported a higher mean number of heterosexual partners in the past 6 months (7.1 versus 1.3), more often had had hepatitis and more often were blood transfusion recipients than HIV negative heterosexual non-IDU.

CONCLUSION

HIV prevalence among IDU in this study did not differ from the prevalences found among other IDU in Amsterdam. However, HIV prevalence among heterosexual non-IDU originating from Surinam and the Netherlands Antilles was high when compared with other non-IDU heterosexuals in Amsterdam and may indicate the presence of heterosexual transmission of HIV. Underreporting of risk behaviour or transmission through blood transfusion however, cannot be excluded completely.

Increasing antigenic and genetic diversity of the V3 variable domain of the human immunodeficiency virus envelope protein in the course of the AIDS epidemic

Population-wide variation in genomic RNA of human immunodeficiency virus type 1 (HIV-1) encompassing the V3 loop of the envelope protein was studied in serum samples of 74 newly infected individuals from three Dutch cohorts: 30 homosexual men, 32 drug users, and 12 hemophiliacs. During acute infection, HIV-1 RNA sequences present in serum are relatively homogeneous, which makes direct sequencing feasible. This offered an opportunity to study the infecting virus variants before mutations had accumulated in the new host. The sampling dates ranged from 1980 to 1991, thus spanning the entire AIDS epidemic in The Netherlands. The diversity in the sequenced region increased over time in both the homosexual and the drug-user risk groups. Furthermore, this increase was associated with an increase in antigenic variation, as witnessed by serum reactivity to a V3 peptide panel. Despite this diversification, some 1990 sequences still closely resembled the earliest 1980 sequence, making ancestral inferences problematic. No evidence was found of a change in the master sequence of the virus quasi-species over time. At the amino acid level, no risk-group-associated variation was found, but at the nucleotide level, the drug-user and homosexual/hemophiliac sequences could be distinguished on the basis of a single silent nucleotide change in the sequence encoding the tip of the V3 loop. Hemophiliac sequences could not be distinguished from those of homosexuals. In spite of the large and increasing genetic variability, all sequences were more similar to the European/American HIV consensus sequence than to that of non-Western strains.

Increase in unprotected anogenital intercourse among homosexual men

Results are presented from two sources, data of which indicate an increase in high-risk sexual behaviors for human immunodeficiency virus infection among homosexual men. The number of cases of gonorrhea among homosexual and bisexual visitors to municipal sexually transmitted disease clinics in Amsterdam, The Netherlands, is increasing. An increase was also observed in unprotected anogenital intercourse among homosexual participants in the Amsterdam cohort. These findings indicate that a rebound in the behavior change process among homosexual men is occurring. Furthermore, longitudinal behavioral data show that lapse and relapse into unsafe sex are prevalent in the Amsterdam cohort.

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.

The HIV epidemic and its effect on the tuberculosis situation in The Netherlands

To determine the influence of the HIV (human immunodeficiency virus) epidemic on the tuberculosis situation in the Netherlands, we made a retrospective analysis of all reported tuberculosis cases from 1984 through 1990. We studied the course of the tuberculosis incidence in the Netherlands among the group at highest risk for HIV infection (Dutch males, 25-49 years of age, in Amsterdam). This was compared with the course among same-age Dutch males in areas with lower risk for HIV infection and among other-age Dutch males in Amsterdam. The tuberculosis incidence among Dutch males aged 25-49 years in Amsterdam increased from 16.1 in 1984 to 34.7 per 100,000 in 1990 (chi 2 for trend, P < 0.01). The incidences among Dutch males in other places of residence in this age group and among other-age Dutch males in Amsterdam remained stable or decreased during the same period. As this increase could not be ascribed to tuberculosis among other risk groups, it appears to be related to the HIV epidemic among male homosexuals. Our results indicate that, even in a country where the prevalence of tuberculous infection is low, an increase of tuberculosis among certain subgroups can be observed as the result of the HIV epidemic.