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

Contribution of sexual health services to hepatitis B detection and control (Netherlands, 2008-2016)

OBJECTIVES

Case finding is one of the priority actions to reduce the disease burden of chronic hepatitis B (CHB). We estimated the contribution of CHB case finding at sexual health centres (SHCs) to the total national number of newly diagnosed CHB cases in the Netherlands and determined the characteristics of CHB cases detected at SHCs.

METHODS

This observational study used surveillance data from all outpatient SHCs in the Netherlands (SOAP database) and the number of CHB from national notification data (Osiris) from 2008 to 2016. The proportion of CHB notifications (hepatitis B surface antigen positive serology) detected at SHCs was calculated. SHC consultations without hepatitis B virus (HBV) testing (n=669 308), with acute hepatitis B diagnosis (n=73), with HBV vaccination only (n=182) or an inconclusive hepatitis B diagnosis (n=24) were excluded. Univariable and multivariable logistic regression analyses were performed, stratified by gender and sexual preference, to analyse patient characteristics associated with CHB.

RESULTS

During the study period, 12 149 CHB cases were notified. 405 646 SHC consultations were included in the analysis and 1452 CHB cases (0.4%) were detected at SHCs. The proportion of CHB cases detected at SHCs in relation to the national notified number ranged between 12.4% (200 of 1613) in 2008 and 10.8% (106 of 980) in 2016. 87% of CHB cases were among first-generation migrants (FGMs) originating from high endemic countries for sexually transmitted infections or men who have sex with men (MSM). In multivariable analysis, an older age category, migration background and being a commercial sex worker (CSW) were associated with CHB in all stratified analyses.

CONCLUSIONS

The contribution of SHCs is relevant to case finding of CHB in the Netherlands. SHCs should therefore be considered as an important health setting to screen for HBV in high-risk groups, especially among MSM, CSW and FGM, to achieve a reduction in the HBV-related disease burden.

Genetic Variation in the MBL2 Gene Is Associated with Chlamydia trachomatis Infection and Host Humoral Response to Chlamydia trachomatis Infection

This study aims to assess the potential association of MBL2 gene single nucleotide polymorphisms (SNPs) to Chlamydia trachomatis infection. We analysed a selected sample of 492 DNA and serum specimens from Dutch Caucasian women. Women were categorized into four groups of infection status based on the results of DNA and antibody tests for C. trachomatis: Ct-DNA+/IgG+, Ct-DNA+/IgG−, Ct-DNA−/IgG+, and Ct-DNA−/IgG−. We compared six MBL2 SNPs (−619G > C (H/L), −290G > C (Y/X), −66C > T (P/Q), +154C > T (A/D), +161A > G (A/B), and +170A > G (A/C)) and their respective haplotypes in relation to these different subgroups. The −619C (L) allele was less present within the Ct-DNA−/IgG+ group compared with the Ct-DNA−/IgG− group (OR = 0.49; 95% CI: 0.28−0.83), while the +170G (C) allele was observed more in the Ct-DNA+/IgG+ group as compared with the Ct-DNA−/IgG− group (OR = 2.4; 95% CI: 1.1−5.4). The HYA/HYA haplotype was more often present in the Ct-DNA−/IgG− group compared with the Ct-DNA+/IgG+ group (OR = 0.37; 95% CI: 0.16−0.87). The +170G (C) allele was associated with increased IgG production (p = 0.048) in C. trachomatis PCR-positive women. This study shows associations for MBL in immune reactions to C. trachomatis. We showed clear associations between MBL2 genotypes, haplotypes, and individuals’ stages of C. trachomatis DNA and IgG positivity.

National trends in sexual health indicators among gay and bisexual men disaggregated by ethnicity: repeated cross-sectional behavioural surveillance in New Zealand

OBJECTIVES

To assess trends in sexual health outcomes among men who have sex with men (MSM) disaggregated by ethnicity.

DESIGN

Repeated cross-sectional.

SETTING

Behavioural surveillance data from 2006, 2008, 2011 and 2014 were collected in-person and online across Aotearoa New Zealand.

PARTICIPANTS

Eligible participants were self-identified men aged 16 years or older who reported sex with another man in the past 5 years. We classified 10 525 participants' ethnicities: Asian (n=1003, 9.8%), Māori (Indigenous people of Aotearoa New Zealand, n=1058, 10.3%), Pacific (n=424, 4.1%) and European (n=7867, 76.8%).

OUTCOME MEASURES

The sexual health outcomes examined were >20 recent (past 6 months) male sexual partners, past-year sexually transmitted infection (STI) testing, past-year STI diagnosis, lifetime and past-year HIV testing, lifetime HIV-positive diagnosis and any recent (past 6 months) condomless anal intercourse with casual or regular partners.

RESULTS

When disaggregated, Indigenous and ethnic minority groups reported sexual health trends that diverged from the European MSM and each other. For example, Asian MSM increased lifetime HIV testing (adjusted OR, AOR=1.31 per survey cycle, 95% CI 1.17 to 1.47) and recent HIV testing (AOR=1.14, 95% CI 1.02 to 1.28) with no changes among Māori MSM or Pacific MSM. Condomless anal intercourse with casual partners increased among Māori MSM (AOR=1.13, 95% CI 1.01 to 1.28) with no changes for Asian or Pacific MSM. Condomless anal intercourse with regular partners decreased among Pacific MSM (AOR=0.83, 95% CI 0.69 to 0.99) with no changes for Asian or Māori MSM.

CONCLUSIONS

Population-level trends were driven by European MSM, masking important differences for Indigenous and ethnic minority sub-groups. Surveillance data disaggregated by ethnicity highlight inequities in sexual health service access and prevention uptake. Future research should collect, analyse and report disaggregated data by ethnicity to advance health equity.

Repeat Chlamydia trachomatis testing among heterosexual STI outpatient clinic visitors in the Netherlands: a longitudinal study

BACKGROUND

Chlamydia infections are common in both men and women, are often asymptomatic and can cause serious complications. Repeat testing in high-risk groups is therefore indicated. In the Netherlands, guidelines on repeat chlamydia testing differ between testing facilities, and knowledge on repeat testing behaviour is limited. Here, we analyse the current repeat testing behaviour of heterosexual STI clinic visitors, and aim to identify groups for which repeat testing advice could be advantageous.

METHODS

Longitudinal surveillance data from all Dutch STI outpatient clinics were used, which included all STI clinic consultations carried out among heterosexual men and women between June 2014 and December 2015. Repeat testing was defined as returning to the same STI clinic between 35 days and 12 months after initial consultation. We calculated chlamydia positivity at repeat test stratified by initial test result and time between consultations. Logistic regression analyses were used to identify predictors of repeat testing, and predictors of having a chlamydia positive repeat test.

RESULTS

In total, 140,486 consultations in 75,487 women and 46,286 men were available for analyses. Overall, 15.4% of women and 11.1% of men returned to the STI clinic within the study period. Highest chlamydia positivity at repeat test was seen 3-5 months after initial positive test. Among both women and men, repeat testing was associated with non-Western ethnicity, having had more than two sex partners in the past 6 months, reporting STI symptoms, having a history of STI, and having a chlamydia positive initial test. Among repeat testers, chlamydia positive repeat test was most strongly associated with younger age, followed by a chlamydia positive initial test.

CONCLUSIONS

Repeat testing most often resulted in a positive test result among young heterosexuals (<25) and heterosexuals of any age with a chlamydia infection at the initial consultation. Further efforts are needed to determine optimal repeat testing strategies.

Ethnic and regional differences in STI clinic use: a Dutch epidemiological study using aggregated STI clinic data combined with population numbers

OBJECTIVES

Ethnic minorities (EM) from STI-endemic countries are at increased risk to acquire an STI. The objectives of this study were to investigate the difference in STI clinic consultation and positivity rates between ethnic groups, and compare findings between Dutch cities.

METHODS

Aggregated population numbers from 2011 to 2013 of 15-44 year-old citizens of Amsterdam, Rotterdam, The Hague and Utrecht extracted from the population register (N=3 129 941 person-years) were combined with aggregated STI clinic consultation data in these cities from the national STI surveillance database (N=113 536). Using negative binomial regression analyses (adjusted for age and gender), we compared STI consultation and positivity rates between ethnic groups and cities.

RESULTS

Compared with ethnic Dutch (consultation rate: 40.3/1000 person-years), EM from Eastern Europe, Sub-Sahara Africa, Suriname, the Netherlands Antilles/Aruba and Latin America had higher consultation rates (range relative risk (RR): 1.27-2.26), whereas EM from Turkey, North Africa, Asia and Western countries had lower consultation rates (range RR: 0.29-0.82). Of the consultations among ethnic Dutch, 12.2% was STI positive. Positivity rates were higher among all EM groups (range RR: 1.14-1.81). Consultation rates were highest in Amsterdam and lowest in Utrecht independent of ethnic background (range RR Amsterdam vs Utrecht: 4.30-10.30). Positivity rates differed less between cities.

CONCLUSIONS

There were substantial differences in STI clinic use between ethnic groups and cities in the Netherlands. Although higher positivity rates among EM suggest that these high-risk individuals reach STI clinics, it remains unknown whether their reach is optimal. Special attention should be given to EM with comparatively low consultation rates.

Changing Patterns of Undiagnosed HIV Infection in the Netherlands: Who Benefits Most from Intensified HIV Test and Treat Policies?

OBJECTIVES

To estimate HIV prevalence, the number of people living with HIV/AIDS (PLWHA) and the undiagnosed proportion in the Netherlands for 2012, and to compare these with published 2007 estimates.

DESIGN

Synthesis of all available data sources.

METHODS

Multi-Parameter Evidence Synthesis (MPES) was used to obtain estimates in mutually exclusive key populations at higher risk in three geographical regions (Amsterdam, Rotterdam, rest of the Netherlands). Data sources included HIV prevalence surveys, diagnoses at STI clinics, and registered cases in HIV care. Group specific estimates were reported as Bayesian posterior medians and 95% credible intervals (CrI).

RESULTS

The 2012 model estimated 24,350 PLWHA (95% CrI 20,420-31,280) aged 15-70 years; 2,906 (+14%) more than in 2007. The estimated population HIV prevalence was 0.20% (95% CrI 0.17-0.26%). The overall proportion of undiagnosed HIV was lower in 2012 (34%, 95% CrI 22-49%) compared to 2007 (40%, 95% CrI 25-55%). After MSM, migrants from sub-Saharan Africa and the Caribbean formed the largest groups of PLWHA, but proportions of undiagnosed HIV remained high in these groups, 48% and 44% respectively. Amsterdam had lowest proportions undiagnosed for most key populations at higher risk, including MSM and migrants.

CONCLUSIONS

In 2012, the number of PLWHA was higher compared to 2007, while the proportion of undiagnosed HIV was lower, especially among MSM. Higher HIV testing rates, earlier treatment, and an improved life expectancy may explain these differences. HIV interventions need to be expanded in all key populations at higher risk, with special focus on migrants and key populationsliving outside of Amsterdam.

Comparison of STI-related consultations among ethnic groups in the Netherlands: an epidemiologic study using electronic records from general practices

Background

Currently, surveillance of sexually transmitted infections (STIs) among ethnic minorities (EM) in the Netherlands is mainly performed using data from STI centers, while the general practitioner (GP) is the most important STI care provider. We determined the frequency of STI-related episodes at the general practice among EM, and compared this with the native Dutch population.

Methods

Electronic medical records from 15–to 60-year-old patients registered in a general practice network from 2002 to 2011 were linked to the population registry, to obtain (parental) country of birth. Using diagnoses and prescription codes, we investigated the number of STI-related episodes per 100,000 patient years by ethnicity. Logistic regression analyses (crude and adjusted for gender, age, and degree of urbanization) were performed for 2011 to investigate differences between EM and native Dutch.

Results

The reporting rate of STI-related episodes increased from 2004 to 2011 among all ethnic groups, and was higher among EM than among native Dutch, except for Turkish EM. After adjustment for gender, age, and degree of urbanization, the reporting rate in 2011 was higher among Surinamese [Odds Ratio (OR) 1.99, 95 % confidence interval (CI) 1.70-2.33], Antillean/Aruban (OR 2.48, 95 % CI 2.04-3.01), and Western EM (OR 1.24, 95 % CI 1.11-1.39) compared with native Dutch, whereas it was lower among Turkish EM (OR 0.48, 95 % CI 0.37-0.61). Women consulted the GP relatively more frequently regarding STIs than men, except for Turkish and Moroccan women.

Conclusions

Most EM consult their GP more often for STI care than native Dutch. However, it remains unclear whether this covers the need of EM groups at higher STI risk. As a first point of contact for care, GPs can play an important role in reaching EM for (proactive) STI/HIV testing.

Electronic supplementary material

The online version of this article (doi:10.1186/s12875-015-0281-2) contains supplementary material, which is available to authorized users.

Seroprevalence and genotype of Chlamydia in pet parrots in China

Parrots are one of the most popular pet birds in China, and can harbour Chlamydia which has significance for human and animal health. We investigated, by indirect haemagglutination assay, the seroprevalence of Chlamydia infection in four species of parrots, namely budgerigars (Melopsittacus undulatus), lovebirds (Agapornis sp.), cockatiels (Nymphicus hollandicus) and Alexandrine parakeets (Psittacula eupatria) that were collected from Weifang and Beijing cities, North China and explored the association between potential risk factors and chlamydial seropositivity. We further determined the genotype of Chlamydia in 21 fresh faecal samples based on the ompA sequence by reconstruction of phylogenetic relationships. Of the 311 parrots examined, 35·37% (95% confidence interval 30·06–40·68) were seropositive, and species, gender, age, season and geographical location were identified as risk factors. Two PCR-positive samples represented Chlamydia psittaci genotype A. The occurrence of C. psittaci genotype A in the droppings of two pet parrots in China suggests potential environmental contamination with Chlamydiaceae and may raise a public health concern.

Serovar D and E of serogroup B induce highest serological responses in urogenital Chlamydia trachomatis infections

Background

Chlamydia trachomatis is the most prevalent bacterial sexually transmitted infection (STI) worldwide. A strong link between C. trachomatis serogroup/serovar and serological response has been suggested in a previous preliminary study. The aim of the current study was to confirm and strengthen those findings about serological IgG responses in relation to C. trachomatis serogroups and serovars.

Methods

The study population (n = 718) consisted of two patient groups with similar characteristics of Dutch STI clinic visitors. We performed genotyping of serovars and used titre based and quantitative commercially available ELISA kits (medac Diagnostika) to determine specific serum IgG levels. Optical density (OD) values generated by both tests were used to calculate the IgG titres (cut-off 1:50). Analyses were conducted stratified by gender.

Results

We observed very significant differences when comparing the median IgG titres of three serogroups, B, C and I: in women for B vs. C: p < 0.0001 (median titres B 200 vs. C <50); B vs. I: p < 0.0001 (200 vs. 50), and in men for B vs. C: p = 0.0006 (150 vs. <50); B vs. I: p = 0.0001 (150 vs. <50); C vs. I was not significant for both sexes. Serovars D and E of serogroup B had the highest median IgG titres compared to the other serovars in both men and women: 200 and 200 vs. ≤ 100 for women and 100 and 200 vs. ≤ 75 for men, respectively.

Conclusions

This study shows that B group serovars induce higher serological responses compared to the C and I group serovars in vivo in both men and women.

Consultations for sexually transmitted infections in the general practice in the Netherlands: an opportunity to improve STI/HIV testing

OBJECTIVES

In the Netherlands, sexually transmitted infection (STI) care is provided by general practitioners (GPs) as well as by specialised STI centres. Consultations at the STI centres are monitored extensively, but data from the general practice are limited. This study aimed to examine STI consultations in the general practice.

DESIGN

Prospective observational patient survey.

SETTING

General practices within the nationally representative Dutch Sentinel GP network (n=125 000 patient population), 2008-2011.

OUTCOME MEASURES

GPs were asked to fill out a questionnaire at each STI consultation addressing demographics, sexual behaviour and laboratory test results. Patient population, testing practices and test positivity are reported.

PARTICIPANTS

Patients attending a consultation concerning an STI/HIV-related issue.

RESULTS

Overall, 1 in 250 patients/year consulted their GP for STI/HIV-related problems. Consultations were concentrated among young heterosexuals of Dutch origin. Laboratory testing was requested for 83.3% of consultations. Overall consult positivity was 33.4%, highest for chlamydia (14.7%), condylomata (8.7%) and herpes (6.4%). 32 of 706 positive patients (4.5%) were diagnosed with multiple infections. Main high-risk groups were patients who were <25 years old (for chlamydia), >25 years old (syphilis), men who have sex with men (MSM; for gonorrhoea/syphilis/HIV) or having symptoms (for any STI). Adherence to guideline-recommendations to test for multiple STI among high-risk groups varied from 15% to 75%.

CONCLUSIONS

This study found that characteristics of patients who consulted a GP for STIs were comparable to those of patients attending STI centres regarding age and ethnicity; however, consultations of high-risk groups like MSM and (clients of) commercial sex workers were reported less by the general practice. Where the STI centres routinely test all patients for chlamydia/syphilis/HIV/gonorrhoea, GPs tested more selectively, even more restricted than advised by GP guidelines. Test positivity was, therefore, higher in general practice, although it is unknown how many STIs are missed (particularly among high-risk groups). Opportunities for a more proactive role in STI/HIV testing at general practices in line with current guidelines should be explored.

Serogroup distribution of urogenital Chlamydia trachomatis in urban ethnic groups in The Netherlands

The prevalence of Chlamydia trachomatis varies between ethnic groups in The Netherlands. It is, however, unknown whether this is associated with specific serogroups. The objective of this study was to determine whether serogroup distribution is associated with ethnic origin in the region of The Hague, The Netherlands. Serogroups of 370 microbiologically confirmed C. trachomatis-positive samples were analysed. The samples were obtained from 247 women and 123 men between January and October 2008, of self-reported Dutch Caucasian, Dutch Antillean, Surinamese, N. African/Turkish or other descent. We observed a difference in serogroup distribution comparing Dutch Caucasian women to Dutch Antillean women (χ2 for distribution P = 0·035). Serogroup C was more common in Dutch Antillean women, whereas serogroup B was less common (P = 0·03). This difference was not observed for Dutch Antillean men. The observed difference in distribution of C. trachomatis serogroups between ethnic groups is relevant for further transmission studies.