Health status in Europe: comparison of 24 urban areas to the corresponding 10 countries (EURO-URHIS 2).

Background: : In Europe, over 70% of the population live in urban areas (UAs). Most international comparative health research is done using national level data, as reliable and comparable urban data are often unavailable or difficult to access. This study aims to investigate whether population health is different in UAs compared with their corresponding countries. : Routinely available health-related data were collected by the EURO-URHIS 2 project, for 10 European countries and for 24 UAs within those countries. National and UA level data for 11 health indicators were compared through the calculation of relative difference, and geographical patterns within Europe were investigated using the Mann Whitney U test. Linear regression modelling was used to adjust for population density, gross domestic product and urbanicity. : In general, the urban population in Eastern Europe is less healthy than the Western European urban population. However, people in Eastern Europe have significantly better broad health outcomes in UAs as compared with the corresponding country as a whole, whereas people in Western Europe have generally worse broader health outcomes in UAs. : For most European countries and UAs that were investigated, the national level health status data does not correspond with the health status at UA level. In order to identify health problems in UAs and to provide information for local health policy, health monitoring and international benchmarking should also be conducted at the local level.

Risk of travelling to the country of origin for tuberculosis among immigrants living in a low-incidence country.

SETTING: Two thirds of tuberculosis (TB) patients in the Netherlands are foreign-born. OBJECTIVE: To determine if travelling to the country of origin is a risk factor for TB among two different immigrant groups that have lived in the Netherlands for at least 2 years. DESIGN: In this unmatched case-control study, the frequency and duration of travel to the country of origin in the preceding 12 months were compared between adult Moroccan and Turkish TB patients and community controls. RESULTS: Moroccan patients had travelled more often (26/32 = 81%) in the preceding year than Moroccan controls (472/816 = 58%). The travel-associated odds ratio (OR) for TB among Moroccans was 3.2 (95%CI 1.3-7.7), and increased to 17.2 (95%CI 3.7-79) when the cumulative duration of travel exceeded 3 months. The corresponding population fraction of Moroccan TB cases attributable to recent travel was 56% (95%CI 19-71). Among Turkish immigrants TB was not associated with travel (OR 0.9, 95%CI 0.3-2.4). CONCLUSION: Travel to the country of origin was a risk factor for TB among Moroccans, but not among Turkish people living in the Netherlands. The difference in travel-associated OR between these two immigrant groups is probably related to differences in TB incidence in these countries.

[Considerable comorbidity in overweight adults: results from the Utrecht Health Project]. / Aanzienlijke comorbiditeit bij volwassenen met overgewicht: resultaten uit het 'Leidsche Rijn Gezondheidsproject'.

OBJECTIVE: To determine the association between overweight, physical and mental health conditions and health-related quality of life in an adult community population upon entering a new primary care practice. DESIGN: Cross-sectional study. METHOD: Baseline data from 4825 participants (mean age: 39 years; 55% women) in the Utrecht Health Project; a dynamic primary care population study with a response rate of over 50%, were used to determine and compare the prevalence of diagnosed medical conditions, complaints and quality of life between individuals of normal weight (BMI 18.5-< 25 kg/m2) and those who were overweight (BMI 25-< 30 kg/m2) or obese (BMI > or = 30 kg/m2). Normal weight was used as the reference category. RESULTS: Overweight individuals were approximately twice as likely to have cardiovascular risk factors and had a 20-60% increased risk of back pain, arthrosis, migraine, dyspepsia and respiratory symptoms than those of normal weight. Obese individuals were almost twice to four times more likely to have these conditions and were additionally at increased risk of obstructive pulmonary disease, cardiovascular disease and arthritis (range of odds ratios (ORs): 1.9-3.3). Somatization and reduced physical well-being were more common among both overweight (ORs: 1.2-1.5) and obese (ORs: 1.7-3.7) individuals, whereas only obese individuals demonstrated a 30-50% increased risk of mental health conditions and reduced mental well-being. CONCLUSION: Overweight was associated with a broad range of physical and mental health conditions and a reduced health-related quality of life. Routine measurement of BMI upon entering a primary care practice is relatively simple and may contribute to the identification of individuals at high risk of comorbidity.

[Smoking, alcohol and drug use in Utrecht, The Netherlands, risk groups and socioeconomic differences in 1999 and 2003]. / Roken, alcohol-en druggebruik in Utrecht, risicogroepen en sociaal-economische verschillen in 1999 en 2003.

OBJECTIVE: To investigate trends in socio-economic inequalities in smoking, alcohol and drug use in the community of Utrecht, the Netherlands. DESIGN: Repeated cross-sectional population surveys. METHOD: Questionnaires were used to collect information about smoking, (problematic) alcohol use and the use of cannabis, ecstasy and other drugs in the general population aged 15-64 years in Utrecht, the Netherlands. Data were collected in 1999 on 2485 responders (response: 56%) and in 2003 on 1840 responders (54%). The male-female ratio was 4:6. RESULTS: The percentage of smokers was 43 in 1999 and 34 in 2003. Excessive use of alcohol was reported by 21% in both 1999 and 2003, cannabis use was reported in 13% and 14%, respectively, and use of hard drugs was reported in 1-3% in both 1999 and 2003. Native Dutch people, men, unmarried people and people with a low education or income level were at increased risk for drinking, smoking and using drugs. People with a low socio-economic status were just as likely to smoke in 1999 as in 2003, while the use of alcohol, cannabis and ecstasy increased. Those with a higher socio-economic status were much less likely to smoke in 2003 than in 1999, while fewer used cannabis and ecstasy use remained the same. CONCLUSION: Socio-economic inequalities in substance abuse were greater in 2003 than in 1999 in the studied population in Utrecht. People with a low socio-economic status showed an increase in unhealthy behaviour concerning the use of alcohol, cannabis and ecstasy.

[Increased consultations and numbers of sexually transmitted diseases at the STD clinic of Utrecht, 1994-2002]. / Toename van het aantal bezoeken en seksueel overdraagbare aandoeningen op de soa-polikliniek van Utrecht, 1994-2002.

OBJECTIVE: To determine trends in numbers of visitors and their demographic characteristics, reasons for visit, number of STDs and high-risk groups. DESIGN: Secondary analysis of registration data. METHOD: Data of every client that visited the STD clinic in Utrecht, the Netherlands, were aggregated from 1994 to 2002 in order to analyse trends. RESULTS: The number of visitors as well as the number of STDs rose strongly over the period investigated. The age of the visitors decreased. In 1994 17% of the visitors was born outside the Netherlands, in 2002 6%. The majority of the clients (56%) visited the STD clinic to get themselves tested preventively and 27% came because of symptoms. Visitors with symptoms or who were warned by others had a three-fold increased risk of having an STD. Other risk groups were: homosexual men, visitors born outside the Netherlands and visitors who have had an STD before. Groups with an increased risk of having a Chlamydia trachomatis infection were: visitors aged under 34 years old and visitors born in Morocco, Surinam and the Antilles. The number of Chlamydia infections rose sharply among homosexual male visitors. CONCLUSION: The increase in the number of visitors and of STD requires an increase in STD prevention, aimed at high-risk groups. More research is needed into the limited help-seeking behaviour of immigrants and more attention needs to be paid to Chlamydia trachomatis infections among homosexual men.

Risk factors of HIV infection and needle sharing among injecting drug users in Ho Chi Minh City, Vietnam.

OBJECTIVE: We sought to identify risk factors for needle sharing and HIV infection among injecting drug users (IDUs) in Ho Chi Minh City (HCMC), Vietnam. METHODS: Three cross-sectional surveys among IDUs, both on the street (in 11 urban districts) and in the rehabilitation center for IDUs in HCMC, were carried out in April of 1995, 1997, and 1998. Outreach workers interviewed IDUs about socio-demographic characteristics, drug use and sexual practices, and HIV knowledge and perceptions. The IDUs were also tested for seropositivity to HIV. Independent predictors for HIV positivity and needle sharing were determined by univariate and multivariate logistic regression for the study sample within the rehabilitation center in 1997 and for that on the street in 1998. RESULTS: The HIV prevalence in 1998 among IDUs was 44% for those on the street and 38.5% for those in the rehabilitation center. Independent predictors for HIV infection in IDUs were being injected by drug dealers (for the 1997 sample), injecting on the street, and sharing the drug pots (for the 1998 sample). The reported rate of needle sharing was low and decreased significantly from 20% in 1995 to 12% in 1998 for the sample of IDUs at the street. In the multivariate analysis, predictors for needle sharing for both study samples were injecting on the street, injecting at shooting galleries, and having shared needles in the past. Adequate and easy access to sterile needles and syringes, and a supportive environment of behavior change, especially in street and shooting gallery could reduce risks of virus transmission in the Vietnamese IDU community.

The impact of harm-reduction-based methadone treatment on mortality among heroin users.

OBJECTIVES: The purpose of this study was to investigate the impact of harm-reduction-based methadone programs on mortality among heroin users. METHODS: A prospective cohort investigation was conducted among 827 participants in the Amsterdam Cohort Study. Poisson regression was used to identify methadone maintenance treatment characteristics (dosage, frequency of program attendance, and type of program) that are significantly and independently associated with mortality due to natural causes and overdose. RESULTS: From 1985 to 1996, 89 participants died of natural causes, and 31 died as a result of an overdose. After adjustment for HIV and underweight status, there was an increase in natural-cause mortality among subjects who left methadone treatment (relative risk [RR] = 2.38, 95% confidence interval [CI] = 1.28, 4.55). Leaving treatment was also related to higher overdose mortality, but only among injection drug users (RR = 4.55, 95% CI = 1.89, 10.00). CONCLUSIONS: Harm-reduction-based methadone treatment, in which the use of illicit drugs is tolerated, is strongly related to decreased mortality from natural causes and from overdoses. Provision of methadone in itself, together with social-medical care, appears more important than the actual methadone dosage.

Large decline in injecting drug use in Amsterdam, 1986-1998: explanatory mechanisms and determinants of injecting transitions.

OBJECTIVES: To study community wide trends in injecting prevalence and trends in injecting transitions, and determinants. DESIGN: Open cohort study with follow up every four months (Amsterdam Cohort Study). Generalised estimating equations were used for statistical analysis. SETTING: Amsterdam has adopted a harm reduction approach as drug policy. PARTICIPANTS: 996 drug users who were recruited from 1986 to 1998, mainly at methadone programmes, who paid 13620 cohort visits. MAIN RESULTS: The prevalence of injecting decreased exponentially (66% to 36% in four to six monthly periods). Selective mortality and migration could maximally explain 33% of this decline. Instead, injecting initiation linearly decreased (4.1% to 0.7% per visit), cessation exponentially increased (10.0% to 17.1%), and relapse linearly decreased (21.3% to 11.8%). Non-injecting cocaine use (mainly pre-cooked, comparable to crack) and heroin use strongly increased. Trends were not attributable to changes in the study sample. CONCLUSIONS: Harm reduction, including large scale needle exchange programmes, does not lead to an increase in injecting drug use. The injecting decline seems mainly attributable to ecological factors (for example, drug culture and market). Prevention of injecting is possible and peer-based interventions may be effective. The consequences of the recent upsurge in crack use requires further study.

Evaluation of hepatitis C antibody testing in saliva specimens collected by two different systems in comparison with HCV antibody and HCV RNA in serum.

Two different ELISA assays, the Ortho HCV 3.0 ELISA (Ortho Diagnostics Systems) and the Mono-Lisa anti-HCV Plus (Sanofi Diagnostics Pasteur) were evaluated for the detection of hepatitis C virus (HCV) antibody in saliva samples. Specimens were collected from 152 individuals who participated in a longitudinal cohort study on HIV infection, and who used illicit drugs. Saliva specimens were collected using two different systems: Salivette (Sarstedt) and Omni-Sal (Saliva Diagnostic Systems). Saliva specimens were tested following modified protocols by both ELISAs, and the results were compared with serum specimens that were tested according to the instructions of the manufacturer. Serum samples of 102 (67%) participants were positive by both assays, and 50 persons were negative for HCV antibody. A total of 99 of the 102 serum specimens were confirmed as positive using Ortho Riba HCV 3.0 (Ortho Diagnostics System) and Deciscan HCV (Sanofi Diagnostics Pasteur), and 3 yielded discrepant results. As no cut-off level is known for testing saliva samples by ELISA, 3 different levels were chosen: mean (M) + 1 standard deviation (SD), M + 2 SD, and M + 3 SD of the optical densities of saliva tests of the 50 HCV serum antibody negative persons. At a level of M + 1 SD and M + 2 SD the Salivette/Mono-Lisa combination gave the greatest proportion of HCV antibody positive saliva specimens obtained from the 102 HCV serum antibody positive participants, 88% and 79%, respectively. Differences between the various collection systems and assay combinations were not significant statistically. In 76 of the 102 persons with HCV antibodies in serum, HCV RNA was detected in serum. Salivary presence of HCV RNA, however, could not be demonstrated. The results show that the assays compared are unsuitable for diagnostic use, but the sensitivities of the assays are acceptable for use in epidemiological studies.

Methadone maintenance and cessation of injecting drug use: results from the Amsterdam Cohort Study.

AIMS: To assess relationships between characteristics of methadone maintenance treatment and long-term cessation of injecting (> or = 1 year). DESIGN AND PARTICIPANTS: The incidence of cessation of injecting and relapse from non-injecting to injecting was estimated among 488 participants of the Amsterdam cohort study among drug users. We used a nested matched case-control design to identify methadone treatment characteristics significantly and independently related to cessation of injecting. To ensure detailed and valid assessment of methadone treatment, data of the Central Methadone Register were linked with cohort data. For 339 of 488 subjects of the initial study group methadone data were available. FINDINGS: The incidence of cessation of injecting increased from 2.2/100 person years in 1985-89 to 5.5/100 per year in 1995-97 (Ptrend = 0.005). Relapse to injecting was high: 17.2/100 person years (no trend). Methadone dosage and frequency of methadone programme attendance in themselves were not significantly related to cessation of injecting. However, an individual increase of 5 mg or more per year (OR 4.20, 95% CI 1.54-11.46) and receiving methadone mainly via the outpatient clinic for drug-abusing prostitutes and foreigners (OR 0.18, 95% CI 0.05-0.59) were independent predictors of cessation of injecting. After cessation of injecting, there were no HIV-seroconversions during the period of non-injecting (129 person years). After relapse to injecting there was one seroconverter; however, follow-up was small (23 person years). The HIV-incidence of those who continued injecting was 3.2/100 per year. CONCLUSIONS: Steadily increasing the methadone dosage in a harm reduction setting may be useful in supporting injecting drug users in the process of cessation of injecting and reducing the spread of HIV-infection.

Prevalence, incidence and risk factors of anaemia in HIV-positive and HIV-negative drug users.

AIMS: To determine the prevalence of anaemia among HIV-positive and -negative drug users, estimate the incidence of anaemia among HIV-positive drug users and study risk factors for prevalent anaemia with emphasis on HIV infection, gender and drug use behaviour. DESIGN, SETTING AND PARTICIPANTS: Cross-sectional study among HIV-positive and HIV-negative drug users (n = 360) and a longitudinal study among HIV-positive drug users (n = 175, 860 visits) participating in a cohort study of drug users in Amsterdam. MEASUREMENTS: Self-reported data on socio-demographics, drug use behaviour and zidovudine and protease inhibitor therapy on regular cohort visits. Laboratory determinations of haemoglobin concentration, CD4(+)-cell counts and HIV-1 RNA. FINDINGS: The prevalence of anaemia was 21.1% among participating drug users according to the WHO definition. The incidence of anaemia in HIV-positive individuals was 33.0/100 person-years. The main risk factor for anaemia was high frequency of injecting drugs. A Quetelet body mass index < or = 20 and female gender were also positively and significantly related to anaemia in the cross-sectional study. In the longitudinal study among HIV-positive drug users progression of HIV infection indicated by low CD4(+)-cell count and AIDS diagnosis were predictive of anaemia. CONCLUSION: The results indicate that drug users in the Amsterdam cohort study have a high prevalence of anaemia, which can be explained mainly by high frequency of injecting drugs and HIV infection progression. Reduction or cessation of injecting drug use should reduce anaemia.

How does tuberculosis relate to HIV positive and HIV negative drug users?

OBJECTIVES: (1) To compare the incidence of active tuberculosis in HIV positive and HIV negative drug users. (2) To describe the main characteristics of the tuberculosis cases. DESIGN: A prospective study was performed from 1986 to 1996 as part of an ongoing cohort study of HIV infection in Amsterdam drug users. METHODS: Data from the cohort study, including HIV serostatus and CD4-cell numbers, were completed with data from the tuberculosis registration of the tuberculosis department of the Amsterdam Municipal Health Service. Analyses were carried out with person time and survival methods. RESULTS: Of 872 participants, 24 persons developed culture confirmed tuberculosis during a total follow up period of 4000 person years (0.60 per 100 py, 95% CI: 0.40, 0.90). Nineteen cases were HIV positive (1.54 per 100 py, 95% CI: 0.86, 2.11) and five HIV negative (0.18 per 100 py, 95% CI: 0.08, 0.43). Multivariately HIV infection (relative risk: 12.9; 95% CI: 3.4, 48.8) and age above 33 years (RR: 6.8; 95% CI: 1.3, 35.0, as compared with age below 27) increased the risk for tuberculosis substantially. Additional findings were: (1) 13 of 22 pulmonary tuberculosis cases (59%) were detected by half yearly radiographic screening of the chest; (2) tuberculosis occurred relatively early in the course of HIV infection at a mean CD4 cell number of 390/microliter; (3) an estimated two thirds of the incidence of tuberculosis observed among HIV positive cases was caused by reactivation; (4) all but one patient completed the tuberculosis treatment. CONCLUSION: HIV infection increases the risk for active tuberculosis in Amsterdam drug users 13-fold. The incidence of tuberculosis in HIV negative drug users is still six times higher than in the overall Amsterdam population. In the absence of contact tracing and screening with tuberculin skin tests, periodic chest radiographic screening contributes substantially to early casefinding of active tuberculosis in Amsterdam drug users.

Methadone maintenance treatment modalities in relation to incidence of HIV: results of the Amsterdam cohort study.

STUDY OBJECTIVE: To evaluate methadone maintenance treatment modalities, prescribed within the concept of harm reduction, in relation to incidence of HIV infection among drug users with a history of methadone treatment in Amsterdam, The Netherlands. DESIGN: Prospective observational cohort study among 582 HIV-negative drug users. To ensure valid and detailed assessment of methadone treatment, data from the Central Methadone Register in Amsterdam were linked to the Amsterdam cohort study among drug users. METHODS: Poisson regression analysis was used to identify independent and significant predictors of incidence of HIV. MAIN RESULTS: During 1906 person years, 58 drug users seroconverted, the overall incidence of HIV being 3.0 per 100 person years with a declining trend for current injectors. An increase in frequency of methadone programme attendance [relative risk (RR), 2.4; 95% confidence interval (CI), 1.2-4.6, compared with no change] and increase in methadone dosage (RR, 0.8; 95% CI, 0.6-1.0, per category of change of 10 mg/day) were significantly associated with incidence of HIV in multivariate analysis. Methadone dosage and frequency of programme attendance in itself were not significant predictors. Other multivariate significant risk factors were homelessness, current injecting and in-patient hospital care. CONCLUSIONS: Among drug users who receive methadone maintenance treatment in a harm-reduction setting, which includes ancillary services such as needle-exchange programmes and HIV testing and counselling, prescription of high methadone dosages is not sufficient to stop the spread of HIV. However, an individual increase of the methadone dosage and measures to achieve high treatment retention could contribute to the prevention of HIV among drug users.

Dose-effect relationship between overdose mortality and prescribed methadone dosage in low-threshold maintenance programs.

The present study evaluates the effectiveness of low-threshold methadone maintenance in reducing overdose mortality. In a prospective cohort study conducted in Amsterdam, 498 Dutch injecting drug users (IDU) provided 1,969 person years of follow-up (1989-1995). Forty-four IDU died in this period, 15 due to illicit drug overdose. Compared to IDU not in maintenance, the adjusted relative risk for overdose mortality among those receiving 5-50 mg, 55-70 mg, and 75+ mg were 0.35, 0.13, and 0.11, respectively (p < .05). Also current injection use and HIV-seropositivity were independent predictors for overdose mortality. Whereas previous studies indicated effectiveness of methadone-assisted detoxification and high-dose maintenance programs in reducing mortality, the present study findings suggest that low-threshold maintenance programs also reduce overdose mortality, with higher dosages being most protective.

The validity of drug users' self-reports in a non-treatment setting: prevalence and predictors of incorrect reporting methadone treatment modalities.

BACKGROUND: Epidemiological studies among drug users are often based on retrospective self-reports. However, among others, memory failure, being under the influence of drugs, psychopathology, misunderstanding of questions and socially desirable answering may generate inaccurate reporting. METHODS: This study validated self-reported current (methadone dosage) and medium-term (main location of methadone dispensing and frequency of methadone programme attendance over the previous 4-6 months) aspects of methadone treatment in the Amsterdam AIDS cohort study among drug users, using data of the Central Methadone Register. In addition to descriptive measures, logistic regression analysis was used (adjusted for intra-individual correlation) to identify subgroups with incorrect reporting. Data collected at 4406 visits of 505 cohort participants were analysed. RESULTS: Current methadone dosage was accurately reported (unweighted kappa [kappa]: 0.94, weighted kappa [kappa W]: 0.97). A low methadone dosage, short duration of school education and depressive or euphoric mood during the interview were significant and independent predictors of incorrect reporting of methadone dosage. For main location of dispensing kappa was 0.82, for frequency of programme attendance kappa was 0.53 and kappa W 0.87. There was a tendency to reporting the extreme answering categories. Infrequent programme attendance was the only significant predictor of incorrectly reporting frequency of programme attendance. CONCLUSIONS: Drug users are able to give valid self-reports in a setting where social desirability does not play an important role. The main reasons of incorrect reporting were impaired cognitive functioning, memory failure and misunderstanding of questions.

HIV monitoring in Vietnam: system, methodology, and results of sentinel surveillance.

OBJECTIVE: To measure the prevalence of and trends in HIV infections in populations defined by sentinel surveillance in Vietnam. METHODS: Surveillance was conducted in eight provinces in 1994, expanded to 12 in 1995 and to 20 in 1996. Sentinel populations were sexually transmitted disease (STD) patients, female sex workers (FSW), injecting drug users (IDU), tuberculosis (TB) patients, pregnant women, and military conscripts. Samples were collected twice yearly for high-risk populations and once yearly for low-risk populations. RESULTS: The overall HIV epidemic in Vietnam comprises several different smaller epidemics. It is primarily associated with injecting drug use, but its extent varies widely throughout the country. In 1998, HIV prevalence rates ranged from 0 to 85% (median, 13.1%), with an aggregate prevalence rate (APR; i.e., the sum of HIV-positive study subjects divided by the sum of all study subjects tested in sentinel provinces) of 17% among IDUs; this ranged from 0 to 14.7% (median, 0.8%), with the APR of 2.4% among FSWs; and from 0 to 6% (median, 0%), with the APR of 0.9% among STD patients. The APRs among antenatal women and army conscripts were less than 0.15%. APRs increased significantly from 1994 to 1998 among STD patients (p < .001), FSWs (p < .001), TB patients (p < .001), and pregnant women (p < .05) in original sentinel provinces. HIV prevalence also increased significantly among younger age groups of IDUs and FSWs. CONCLUSION: Vietnam's HIV epidemic is increasing predominantly and most rapidly among IDUs. However, prevalence rates among FSWs and STD patients are rising but are still low among pregnant women and army conscripts. Vietnam, at present, is still in the early phase of the HIV epidemic and has time to take effective and appropriate actions.

Pre-AIDS mortality and morbidity among injection drug users in Amsterdam and Baltimore: an ecological comparison.

Mortality and morbidity between injecting drug users in Amsterdam (n = 624) and Baltimore (n = 2,185) are compared to generate a hypothesis about the role of different health care systems and drug user policies (universal care and harm reduction versus episodic care and criminalization, respectively). Overdose/suicide mortality was twofold higher in Amsterdam; no sufficient explanation was found. Other independent "risk factors" for overdose/suicide mortality were recent injecting, polydrug use, and HIV-seropositivity (especially with CD4 count < 200/mm3). High dose methadone maintenance was associated with lower mortality. Incidence of hospitalizations and emergency room visits was substantially lower in Amsterdam, suggesting that higher accessibility to primary care in Amsterdam lowers (inpatient) hospital visits and presumably societal costs.

New evidence to reconcile in vitro and epidemiologic data on the possible role of heroin on CD4+ decline among HIV-infected injecting drug users.

Long-term effects of drug type and other drug use related risk factors on CD4+ cell decline were assessed in 224 HIV-infected injecting drug users (IDUs) from Baltimore (ALIVE), USA, and 63 IDUs from Amsterdam, The Netherlands. Higher frequencies of borrowing used injection equipment since 1980 resulted in a higher CD4+ count already present before seroconversion (P = 0.049). Use of mainly heroin in the seroconversion interval resulted in a sharper CD4+ decline until the first 6 months after seroconversion (P = 0.004), but CD4+ values converged later on. This finding might reconcile earlier discordant epidemiological and laboratory study results regarding the possible effects of heroin.