Reducing health disparities: key factors for successful implementation of social network testing with HIV self-tests among men who have sex with men with a non-western migration background in the Netherlands.

Improving testing uptake among men who have sex with men with a non-western migration background (MSM-NW) is a public health priority, as people who are unaware of their HIV infection are at higher risk of transmitting HIV and are unable to benefit from HIV treatment. Formative semi-structured interviews with 13 MSM-NW assessed key factors for the successful implementation of social network testing with HIV self-tests (SNT-HIVST). Interviews were thematically analysed. Participants mentioned that SNT-HIVST might overcome barriers to regular HIV testing including; being seen while testing, disclosure of sexual identity, and stigma related to HIV and sexual practices. Trust between the HIVST distributer and receiver was important. Finally, SNT-HIVST requires tailored peer support to address practical, informational, and emotional needs. MSM-NW distributing HIVST can have an important role in reducing health disparities in testing uptake among MSM-NW. Provided sufficient trust among MSM-NW; key factors found for successful implementation were education through an e-tool, and establishing quality support by a peer-coordinator for unanticipated questions. In conclusion, HIVST distribution has the potential to reduce health disparities in testing uptake, in particular, if adjusted to MSM-NWs individual preferences and the needs and preferences of the person they are inviting to test.

Chronic hepatitis B and C infections in the Netherlands: estimated prevalence in risk groups and the general population.

Chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are usually asymptomatic for decades, thus targeted screening can prevent liver disease by timely diagnosis and linkage to care. More robust estimates of chronic HBV and HCV infections in the general population and risk groups are needed. Using a modified workbook method, the total number of ever chronically infected individuals in the Netherlands in 2016 was determined using population size and prevalence estimates from studies in the general and high-risk population. The estimated 2016 chronic HBV infection prevalence is 0.34% (low 0.22%, high 0.47%), corresponding to approximately 49 000 (low 31 000, high 66 000) HBV-infected individuals aged 15 years and older. The estimated ever-chronic HCV infection prevalence is 0.16% (low 0.06%, high 0.27%), corresponding to approximately 23 000 (low 8000, high 38 000) ever-chronic HCV-infected individuals. The prevalence of chronic HBV and HCV infections in the Netherlands is low. First-generation migrants account for most infections with 81% and 60% of chronic HBV and HCV infections, respectively. However, about one-fifth of HCV infections is found in the general population at low risk. This method can serve as an example for countries in need of more accurate prevalence estimates, to help the design and evaluation of prevention and control policies.

[Mapping HIV prevalence in the Netherlands with geographic information systems]. / Hiv-bestrijding begint met GIS-werk.

OBJECTIVE: To map regions of the Netherlands with high HIV prevalence for surveillance and prevention purposes. METHOD: Information on numbers of HIV patients receiving clinical care on 31 December 2014 per postcode region was requested from the HIV monitoring foundation (SHM). These details were related to data from Statistics Netherlands on the number of residents per municipal area or district with the aid of a geographic information system (GIS). RESULTS: Distribution mapping showed that ten municipal areas in the Netherlands have an HIV prevalence of 2 or more per 1000 residents aged 15-60 years. We discovered the highest prevalence in Amsterdam (8.1) and suburbs, Rotterdam (3.4), The Hague (2.7) and Arnhem (2.5). Large differences were seen between districts, particularly in Amsterdam where HIV was concentrated within two districts: Central Amsterdam (9-28) and Amsterdam Southeast (5-20). In Rotterdam and The Hague, HIV prevalence rates are lower and differences between districts are smaller. CONCLUSION: Geographical analyses show differences in HIV prevalence for municipal areas and districts in big cities in the Netherlands. These data can be used for new interventions, to better focus HIV detection.

Missed opportunities to offer HIV tests to high-risk groups during general practitioners' STI-related consultations: an observational study.

OBJECTIVES: Prior research has shown that Dutch general practitioners (GPs) do not always offer HIV testing and the number of undiagnosed HIV patients remains high. We aimed to further investigate the frequency and reasons for (not) testing for HIV and the contribution of GPs to the diagnosis of HIV infections in the Netherlands. DESIGN: Observational study. SETTING: (1) Dutch primary care network of 42-45 sentinel practices where report forms during sexually transmitted infection (STI)-related consultations were routinely collected, 2008-2013. (2) Dutch observational cohort with medical data of HIV-positive patients in HIV care, 2008-2013. OUTCOME MEASURES: The proportion of STI-related consultations in patients from high-risk groups tested for HIV, with additional information requested from GPs on HIV testing preconsultation or postconsultation for whom HIV testing was indicated, but not performed. Next, information was collected on the profile of HIV-positive patients entering specialised HIV care following diagnosis by GPs. RESULTS: Initially, an HIV test was reported (360/907) in 40% of STI-related consultations in high-risk groups. Additionally, in 26% of consultations an HIV test had been performed in previous or follow-up consultations or at different STI-care facilities. The main reasons for not testing were perceived insignificant risk; 'too' recent risk according to GPs or the reluctance of patients. The initiative of the patient was a strong determinant for HIV testing. GPs diagnosed about one third of all newly found cases of HIV. Compared with STI clinics, HIV-positive patients diagnosed in general practice were more likely to be older, female, heterosexual male or sub-Saharan African. CONCLUSIONS: In one-third of the STI-related consultations of persons from high-risk groups, no HIV test was performed in primary care, which is lower than previously reported. Risk-based testing has intrinsic limitations and implementation of new additional strategies in primary care is warranted.

Hepatitis C virus prevalence in The Netherlands: migrants account for most infections.

A population-based anti-hepatitis C virus (HCV) prevalence is important for surveillance purposes and it provides insight into the burden of disease. The outcomes of recent studies in the general Dutch population as well as recent HCV data from specific risk groups including migrants, men who have sex with men (MSM) and injecting drug users (IDUs), were implemented in a modified version of the Workbook Method (a spreadsheet originally designed for HIV estimations), to estimate Dutch HCV seroprevalence. The estimated national seroprevalence of HCV was 0·22% (min 0·07%, max 0·37%), corresponding to 28 100 (min n = 9600, max n = 48 000) HCV-infected individuals in The Netherlands. Of these, first-generation migrants from HCV-endemic countries (HCV prevalence ≥2%) accounted for the largest HCV-infected group, followed by IDUs and HIV-positive MSM.

Comparing two definitions of ethnicity for identifying young persons at risk for chlamydia.

Ethnic disparities in chlamydia infections in The Netherlands were assessed, in order to compare two definitions of ethnicity: ethnicity based on country of birth and self-defined ethnicity. Chlamydia positivity in persons aged 16-29 years was investigated using data from the first round of the Chlamydia Screening Implementation (CSI, 2008-2009) and surveillance data from STI centres (2009). Logistic regression modelling showed that being an immigrant was associated with chlamydia positivity in both CSI [adjusted odds ratio (aOR) 2·3, 95% confidence interval (CI) 2·0-2·6] and STI centres (aOR 1·4, 95% CI 1·3-1·5). In both settings, 60% of immigrants defined themselves as Dutch. Despite the difference, classification by self-defined ethnicity resulted in similar associations between (non-Dutch) ethnicity and chlamydia positivity. However, ethnicity based on country of birth explained variation in chlamydia positivity better, and is objective and constant over time and therefore more useful for identifying young persons at higher risk for chlamydia infection.

Disassortative sexual mixing among migrant populations in The Netherlands: a potential for HIV/STI transmission?

To gain insight into the transmission of HIV and sexually transmitted infection (STI) among large migrant groups in The Netherlands, we studied the associations between their demographic and sexual characteristics, in particular condom use, and their sexual mixing patterns with other ethnic groups. In 2002-2005, cross-sectional surveys were conducted among migrants from Surinam (Afro- and Hindo-), the Netherlands Antilles, Cape Verde, and Ghana at social venues in three large cities. A questionnaire was administrated and a saliva sample was collected for HIV antibody testing. Of 2105 migrants recruited, 1680 reported sexual contacts, of whom 41% mixed sexually with other ethnicities, including the indigenous Dutch population. Such disassortative mixing was associated with being second-generation migrant, having several sexual partners, and having a steady and concurrent casual partner. Less disassortative mixing occurred in participants reporting visiting the country of origin. The association between condom use and sexual mixing differed by gender, with men using condoms inconsistently being most likely to be mixing with the Dutch indigenous population. HIV infection and recent STI treatment were not associated with disassortative mixing. This study shows substantial sexual mixing among migrant groups. Since disassortative mixing is more prevalent in second-generation migrants, it might increase in the upcoming years. The mixing patterns in relation to concurrency and the reported condom use in this study suggest a possibly increased level of HIV/STI transmission not only within migrant groups but also between migrant groups, especially via men who mix with the indigenous population and via migrant women who mix with non-Dutch casual partners. Although the observed HIV prevalence in migrants (0.6%) is probably too low to lead to much HIV transmission between ethnicity groups, targeted prevention measures are needed to prevent transmission of other STI.

[Hepatitis B virus transmission patterns in the Netherlands, 2004]. / Transmissiepatronen van hepatitis B-virus in Nederland, 2004.

OBJECTIVE: To gain insight into hepatitis B virus (HBV) transmission in the Netherlands. DESIGN: Descriptive. METHOD: During 2004, epidemiological data and blood samples (if available) were collected for all reported cases of acute HBV infections in the Netherlands. Following DNA isolation and amplification a 648 base pairs fragment of the HBV S gene was sequenced and subjected to phylogenetic analysis. The sequencing details were also linked to epidemiological information. RESULTS: In 2004, 291 cases ofacute HBV infections were reported. Blood samples were received from 171 patients (59%), and the genotype could be determined for 158 patients (54%). 6 genotypes were identified: A (64%), B (3%), C (3%), D (21%), E (5%) and F (4%). Of all patients with genotype A, 52% had been infected via homosexual or bisexual contact and 16% via heterosexual contact. Of all patients with genotype D, 42% had been infected via heterosexual contact and 15% via homosexual or bisexual contact. The genotype A cluster was extremely homogeneous with many identical sequences, while genotype B-E clusters were more heterogeneous. 4 identical sequences were found within genotype F, but the patients could not be epidemiologically linked. CONCLUSION: Sexual transmission, particularly via homosexual or bisexual contact in men, formed the most important risk factor for acquiring an acute HBV infection. Genotype A was predominant in the Netherlands, especially among homosexual or bisexual men. Most infections within genotype D occurred as a result of heterosexual contact. The results show that there was ongoing transmission of HBV in homosexual or bisexual men, while in heterosexuals more cases of new introduction were seen, possibly via chronic carriers from areas where HBV is endemic.

[Hepatitis B surveillance in the Netherlands, 2002-2005: acute infection is mainly via sexual contact while chronic infection is via vertical transmission through mothers from endemic regions]. / Surveillance van hepatitis B in Nederland, 2002-2005: acute infectie vooral via seksueel contact, chronische via verticale transmissie door moeders uit endemische gebieden.

OBJECTIVE: To study the trends in the prevalence of hepatitis B infections in the Netherlands on the basis of reported cases. DESIGN: Retrospective, descriptive. METHOD: Analysis of data collected from the obligatory notification of hepatitis B to the Dutch Public Health Services in the Netherlands in the period 2002-2005. RESULTS: In the period from January 2002 to December 2005, 7352 hepatitis B virus (HBV) infections were reported, of which 1168 (16%) were acute and 5849 (80%) were chronic infections. Of the acute HBV infections, 34% were transmitted by homo- or bisexual contact and 25% by heterosexual contact. The number of reports of acute HBV infection due to heterosexual transmission increased significantly and originated relatively more often in Dutch patients. The number of reports of chronic HBV infection in men increased significantly; in women there was a decrease over time. Of the chronic HBV infections, 40% were transmitted from mother to child; this was reported especially often by patients from HBV endemic areas. CONCLUSION: Sexual contact was the most important risk factor for the transmission of acute HBV infections, whereas vertical transmission was the greatest risk factor by far for chronic HBV infection. Transmission via heterosexual contact had become increasingly important in the transmission of acute HBV; transmission by homo- or bisexual contact remained constant. Immigration continued to play an important role in the epidemiology of HBV in the Netherlands; the majority of the chronic carriers had been born and infected in an HBV endemic area.

Molecular epidemiology of acute hepatitis B in the Netherlands in 2004: nationwide survey.

To gain insight into hepatitis B virus (HBV) transmission in the Netherlands, epidemiological data and sera were collected from reported cases of acute HBV infections in the Netherlands in 2004. Cases were classified according to mode of transmission. A fragment of the S-gene of HBV (648 bp) was amplified, sequenced, and subjected to phylogenetic analysis. Of the 291 acute HBV cases reported in 2004, 158 (54%) were available for genotyping. Phylogenetic analysis identified 6 genotypes: A (64%), B (3%), C (3%), D (21%), E (5%) and F (5%). Of HBV infected men having sex with men, 86% were infected with genotype A, accounting for 43% of all patients infected with this genotype. There were only three reported cases of injecting drug use of which one was available for sequencing (genotype A). Unlike the genotype A cluster, sequences within the genotype B-E clusters were heterogenic. Within genotype F, several isolates had identical sequences, but patients could not be epidemiologically linked. Sexual transmission, particularly by men having sex with men was the most important transmission route for HBV. Injecting drug use plays a minor role. Genotype A is predominant in the Netherlands, especially among men having sex with men. In addition to imported strains, there seems to be a pool of related but non-identical strains circulating among chronic carriers in the migrant population, from which occasionally new patients are infected, primarily by heterosexual transmission.

[Trends in HIV prevalence and risk behaviour among injecting drug users in Rotterdam, I994-2002]. / Trends in HIV-prevalentie en risicogedrag onder injecterende druggebruikers in Rotterdam, 1994-2002.

OBJECTIVE: To gain insight into the prevalence of HIV infection, the determinants thereof and the risk behaviour in injecting drug users (IDUs) in Rotterdam, The Netherlands, in 2002 in comparison to the HIV survey data from 1994 and 1997. DESIGN: Questionnaire study. METHOD: In 1994-2002, three periodic HIV surveys were conducted in Rotterdam among IDUs using semi-structured questionnaires on risk behaviour and saliva samples for HIV-antibody determination. In the present study, the data for 2002 were analysed and compared with those from 1994 and 1997. RESULTS: The number of participants recruited was 494, 470 and 452, respectively. HIV prevalence did not change over time: 1994: 11.4%, 1997: 9.4% and 2002: 10.2%. In the 2002 survey, independent risk factors for HIV were homelessness and onset of injecting drug use at an early age. The percentage of IDUs that had recently shared needles declined from 18% in 1994 to 8% in 2002. Risky sexual behaviour remained prevalent: inconsistent condom use was reported by 85% with steady partners, 43% with casual partners and 31% with clients. The IDUs who knew that they were HIV positive used condoms consistently more often. CONCLUSION: The combination of a relatively high HIV prevalence among IDUs in Rotterdam and the high level of unsafe sexual behaviour results in a serious risk of further spread of HIV among both IDUs and the general population.

[HIV-infection and AIDS in the Netherlands: prevalence and incidence, 1987-2001]. / HIV-infectie en aids in Nederland: prevalentie en incidentie, 1987-2001.

OBJECTIVE: To describe the results of HIV-surveillance activities in the Netherlands between 1987 and 2001. DESIGN: Descriptive. METHOD: Data were obtained from HIV-surveillance at STI-clinics, laboratory-surveillance in the region Arnhem, surveillance among injecting drug users, the AIDS-notification, STI-registration and the Amsterdam cohort studies on HIV/AIDS. RESULTS: In the Netherlands, the highest HIV-prevalences were found among injecting drug users (1-26%) and homo- and bisexual men (0-17%). In these high-risk populations, an increase in HIV-prevalence and--incidence, respectively, was found among injecting drug users in Heerlen and homosexual men (> 35 years of age) in Amsterdam. The HIV-prevalence was lower among heterosexuals in the Netherlands (0-2%). However, in certain local populations an increase was seen. In both Amsterdam and Rotterdam, the HIV-prevalence was higher in individuals tested anonymously than in those tested by name. CONCLUSION: Local increases in HIV-infections have been observed recently, in both high- and medium-risk populations.

Molecular epidemiology of hepatitis B virus in Amsterdam 1992-1997.

To gain insight into the spread of hepatitis B among various risk groups in Amsterdam a 6-year (1992-1997) retrospective DNA sequencing study was carried out on isolates from stored sera from reported primary cases of acute hepatitis B infection. Cases were classified according to risk behavior, as determined in interviews. Of the available serum, a selected region of hepatitis B-virus-DNA was amplified and sequenced. The nucleotide alignments were subjected to phylogenetic tree analysis. When nucleotide alignments were subjected to phylogenetic analysis, the strains of 54 isolates, 26% of the 204 reported primary cases, clustered in five genotypes: A, C, D, E, and F. In genotype A, a cluster related to men having sex with men was identified. In genotype D, two subclusters could be identified: one was related to injecting drug use and another was related to the Moroccan population in Amsterdam. The remaining strains showed a high genetic variability within three different genotypes: F, E, and C. Of the 14 identical isolates in the "homosexual men cluster," one was isolated from a female heterosexual. Of the 14 identical strains in the "drug users strain," six were from non-drug using heterosexual active individuals. In the cluster of twelve isolates related to hepatitis B-endemic areas, probable modes of transmission were varied. Sequence analysis provides important insight into the spread of hepatitis B among various high-risk groups. The analysis indicates that the prevention strategy in The Netherlands fails to stop transmission of hepatitis B from persistently infected individuals originating from hepatitis B endemic countries.

The impact of immigration on env HIV-1 subtype distribution among heterosexuals in the Netherlands: influx of subtype B and non-B strains.

OBJECTIVE: To examine the epidemiological factors influencing the distribution and spread of HIV-1 subtypes among heterosexuals in the Netherlands. METHOD: A nationwide serosurveillance in 21 HIV/AIDS centres from 1997 to 1999 involved 200 individuals for whom the mode of HIV transmission was heterosexual contact or unknown. HIV-1 subtypes were determined by phylogenetic analysis of env V3 sequences and correlated with sociodemographic characteristics of the subjects and their sexual partners. RESULTS: HIV-1 subtype B infection occurred in 121 subjects (60%). Non-B subtypes were identified in 31 (A), 24 (C), 10 (D), six (E), four (F) and three (G) individuals; one had an unclassified subtype. The proportion of subtype B was about 60% in four of the six regions of the Netherlands, but in the Northwest and Southwest regions these proportions were 76% and 46%, respectively. The Surinamese and Antilleans, large immigrant groups, were all infected with subtype B, as were almost all individuals with an unknown source. The proportions of non-B viruses did not change significantly over time in Amsterdam, where subtyping was available from 1988 onward, but a shift in the various subtype B strains was observed, suggesting introductions of new subtype B strains in Amsterdam. CONCLUSION: To date, HIV-1 non-B subtypes in the Netherlands are still found predominantly among heterosexuals with an epidemiological link with sub-Saharan Africa. Despite continuing introductions of non-B subtypes, the B/non-B distribution has been stable over time, most likely as a result of introductions of subtype B strains from Caribbean and South American countries.

Using phylogenetic analysis to trace HIV-1 migration among western European injecting drug users seroconverting from 1984 to 1997.

OBJECTIVE: To reconstruct the epidemiological relationships of the HIV epidemics among injecting drug users (IDU) in western Europe. METHODS: HIV env V3 sequences of and epidemiological data were obtained from 145 IDU who seroconverted in three sequential periods: 1984-1988, 1989-1992 and 1993-1997. The sequences were phylogenetically analysed and examined for signature patterns characteristic of northern European IDU, including the conserved GGC codon in the V3 loop. RESULTS: Subpopulations of genetically related HIV strains were observed in Italy, France, Scotland and Spain, in contrast to the Netherlands, Austria and Switzerland. This difference between the two groups of countries suggests that the HIV epidemics amongst IDU in the latter group was caused by multiple virus introductions. In Edinburgh and the surrounding area, most IDU were infected with the same GGC strain over the 12-year study period. The epidemic among IDU in north-western Europe started with GGC viruses, whereas in south-western Europe non-GGC viruses predominated. This geographical separation has faded during the course of the epidemic, most likely because of virus exchange among IDU populations.

HIV-1 strains specific for Dutch injecting drug users in heterosexually infected individuals in The Netherlands.

OBJECTIVE: To study the molecular epidemiology of HIV-1 subtype B amongst heterosexually infected individuals in The Netherlands. DESIGN: The study population comprised 54 individuals infected by subtype B viruses through heterosexual contacts. Serum samples were collected between 1988 and 1996. METHODS: Sequences of the gp120 V3 region were obtained from serum samples and analysed by using the signature pattern and phylogenetic methods. RESULTS: In 22 (41%) out of 54 subtype B sequences from heterosexually infected individuals, the synonymous nucleotide substitution in the second glycine codon at the tip of the V3 loop (the GGC pattern), previously identified as specific for Dutch injecting drug users (IDU), was found. The other previously described IDU sequence patterns were observed significantly more often among GGC- than among non-GGC-containing sequences. In addition, we identified another amino-acid change specific for the GGC sequences. In the phylogenetic and principal coordinate analyses, the GGC sequences from heterosexually infected individuals clustered separately from the non-GGC sequences and together with the IDU consensus sequence. Both the nonsynonymous and particularly the synonymous distances amongst the GGC sequences were significantly lower than amongst the non-GGC sequences. CONCLUSIONS: Our data provide evidence for a common origin of the viruses in Dutch IDU and the GGC viruses in heterosexuals. We suggest that a considerable proportion of the viruses in heterosexually infected individuals in The Netherlands may have originated from Dutch IDU.