J E A M van Bergen

Prevalence of urogenital Chlamydia trachomatis increases significantly with level of urbanisation and suggests targeted screening approaches: results from the first national population based study in the Netherlands

Objectives:Chlamydia trachomatis (Chlamydia) is the most prevalent sexually transmitted bacterial infection and can cause considerable reproductive morbidity in women. Chlamydia screening programmes have been considered but policy recommendations are hampered by the lack of population based data. This paper describes the prevalence of Chlamydia in 15–29 year old women and men in rural and urban areas, as determined through systematic population based screening organised by the Municipal Public Health Services (MHS), and discusses the implications of this screening strategy for routine implementation. Methods: Stratified national probability survey according to “area address density” (AAD). 21 000 randomly selected women and men in four regions, aged 15–29 years received a home sampling kit. Urine samples were returned by mail and tested by polymerase chain reaction (PCR). Treatment was via the general practitioner, STI clinic, or MHS clinic. Results: 41% (8383) responded by sending in urine and questionnaire. 11% (2227) returned a refusal card. Non-responders included both higher and lower risk categories. Chlamydia prevalence was significantly lower in rural areas (0.6%, 95% CI 0.1 to 1.1) compared with very highly urbanised areas (3.2%, 95% CI 2.4 to 4.0). Overall prevalence was 2.0% (95% CI 1.7 to 2.3): 2.5% (95% CI 2.0 to 3.0%) in women and 1.5% (95% CI 1.1 to 1.8) in men. Of all cases 91% were treated. Infection was associated with degree of urbanisation, ethnicity, number of sex partners, and symptoms. Conclusion: This large, population based study found very low prevalence in rural populations, suggesting that nationwide systematic screening is not indicated in the Netherlands and that targeted approaches are a better option. Further analysis of risk profiles will contribute to determine how selective screening can be done.

A prediction rule for selective screening of Chlamydia trachomatis infection

Background: Screening for Chlamydia trachomatis infections is aimed at the reduction of these infections and subsequent complications. Selective screening may increase the cost effectiveness of a screening programme. Few population based systematic screening programmes have been carried out and attempts to validate selective screening criteria have shown poor performance. This study describes the development of a prediction rule for estimating the risk of chlamydial infection as a basis for selective screening. Methods: A population based chlamydia screening study was performed in the Netherlands by inviting 21 000 15–29 year old women and men in urban and rural areas for home based urine testing. Multivariable logistic regression was used to identify risk factors for chlamydial infection among 6303 sexually active participants, and the discriminative ability was measured by the area under the receiver operating characteristic curve (AUC). Internal validity was assessed with bootstrap resampling techniques. Results: The prevalence of C trachomatis (CT) infection was 2.6% (95% CI 2.2 to 3.2) in women and 2.0% (95% CI 1.4 to 2.7) in men. Chlamydial infection was associated with high level of urbanisation, young age, Surinam/Antillian ethnicity, low/intermediate education, multiple lifetime partners, a new contact in the previous two months, no condom use at last sexual contact, and complaints of (post)coital bleeding in women and frequent urination in men. A prediction model with these risk factors showed adequate discriminative ability at internal validation (AUC 0.78). Conclusion: The prediction rule has the potential to guide individuals in their choice of participation when offered chlamydia screening and is a promising tool for selective CT screening at population level.

The value of testing multiple anatomic sites for gonorrhoea and chlamydia in sexually transmitted infection centres in the Netherlands, 2006–2010

National surveillance data from 2006 to 2010 of the Dutch sexually transmitted infection (STI) centres were used to analyse current practices on testing extragenital sites for chlamydia and gonorrhoea in men who have sex with men (MSM) and women. In MSM, 76.0% and 88.9% were tested at least at one extragenital site (pharyngeal and/or anorectal) for chlamydia and gonorrhoea, respectively; for women this was 20.5% and 30.2%. Testing more than one anatomic site differed by STI centre, ranging from 2% to 100%. In MSM tested at multiple sites, 63.0% and 66.5% of chlamydia and gonorrhoea diagnoses, respectively, would have been missed if screened at the urogenital site only, mainly anorectal infections. For women tested at multiple sites, the proportions of missed chlamydia and gonorrhoea diagnoses would have been 12.9% and 30.0%, respectively. Testing extragenital sites appears warranted, due to the numerous infections that would have been missed. Adding anorectal screening to urogenital screening for all MSM visiting an STI centre should be recommended. Since actual testing practices differ by centre, there is a need for clearer guidelines. Routine gonorrhoea and chlamydia screening at multiple sites in STI centres should be investigated further as this might be a more effective approach to reduce transmission than current practice.

Who tests whom? A comprehensive overview of Chlamydia trachomatis test practices in a Dutch region among different STI care providers for urogenital, anorectal and oropharyngeal sites in young people: a cross-sectional study

Objectives To evaluate and compare Chlamydia trachomatis (CT) diagnostic test practices of different sexually transmitted infection (STI) care providers in 16–29 year olds from one defined geographic Dutch region (280 000 inhabitants). Both number and proportion of positive CT tests (ie, test positivity) were assessed, and factors associated with these outcomes. Methods Data on laboratory testing and diagnosis of urogenital, anorectal and oropharyngeal CT between 2006 and 2010 were retrieved from general practitioners (GPs), gynaecologists, an STI clinic and a population-based chlamydia screening programme. Multivariable regression analyses explored associations between age, sex, test year, socio-economic status (SES) and STI care provider and the outcomes being the number of tests and test positivity. Results Overall, 22 831 tests were performed (1868 positive; 8.2%). Extragenital (ie, anorectal and oropharyngeal) tests accounted for 4% of all tests (7.5% positive) and were almost exclusively (99%) performed by the STI clinic. STI clinics tested most men (37.2% of all tested men), whereas GPs tested most women (29.9% of all tested women). GPs and STI clinics accounted for 73.3% (1326/1808) of urogenital CT diagnoses. In women, the number of tests increased with age, whereas test positivity decreased for all STI care providers. Lower SES was associated with higher test positivity in GP and gynaecology patients. Conclusions STI clinics performed most CT tests in men, whereas GPs performed most CT tests in women. GPs and STI clinics accounted for the majority of positives. Extragenital CT testing is rarely performed outside the STI clinic and needs to be promoted, especially in men who have sex with men.

Chlamydia trachomatis IgG seroprevalence in the general population of the Netherlands in 1996 and in 2007: differential changes by gender and age

Objectives Chlamydia trachomatis (CT) reporting rates from sexually transmitted infection clinics and general practitioners have shown a rising trend in the Netherlands. It is unknown to what extent this reflects increased CT transmission or improved case finding. To achieve more insight into the CT epidemic, we explored the CT IgG seroprevalence (a marker of past CT infection) in the general population of the Netherlands in 1996 and in 2007. Methods From two population-based studies in 1996 and 2007, serum samples, demographic and sexual behaviour outcomes were examined, including 1246 men and 1930 women aged 15–39 years. Serum CT IgG antibodies were analysed using the Medac CT IgG ELISA test. Multivariate logistic regression analyses explored the seroprevalence and determinants over time. Results The CT IgG seroprevalence was higher in women than in men (10% vs 6%). Among women aged 25–39 years the seroprevalence was lower in 2007 (9%) than in 1996 (14%; adjusted OR (aOR) 0.6, 95% CI 0.4 to 0.8). There was no statistical evidence of a difference in seroprevalence within birth cohorts. Factors associated with seropositivity were male gender (aOR 0.4, 95% CI 0.3 to 0.7), a self-reported history of CT infection (aOR 5.1, 95% CI 2.6 to 10.0), age 25–39 years (aOR 1.7, 95% CI 1.1 to 2.7), non-Western ethnicity (aOR 2.2, 95% CI 1.4 to 3.3) and ≥2 recent sexual partners (aOR 2.2, 95% CI 1.3 to 3.5). Conclusions Between 1996 and 2007 the proportion of individuals in the general population with CT IgG antibodies was lower among women aged 25–39 years, but remained similar among younger women and men.

Proactiever testen op hiv is nodig

SamenvattingJoore IK, Op de Coul ELM, Bom BCJ, Van Sighem AI, Geerlings SE, Prins JM, Van Bergen JEAM. Proactiever testen op hiv is nodig. Huisarts Wet 2017;60(1):24-6. Elk jaar worden in Nederland ongeveer 1000 nieuwe hiv-diagnoses gesteld. Bij een groot deel van deze patiënten (44%) gebeurt dat relatief laat in het ziektebeloop. Vroegtijdige behandeling van hiv na diagnose heeft grote voordelen, voor de patiënt én voor de volksgezondheid. Vroegtijdige opsporing is dus van groot belang. Vooralsnog heeft het testen van risicogroepen onvoldoende geleid tot kentering van de hiv-epidemie in Nederland. Twee nieuwe teststrategieën, naast het testen binnen risicogroepen, zijn het aanbieden van hiv-tests aan patiënten met hiv-gerelateerde aandoeningen (‘hiv-indicatoraandoeningen’) en het routinematig proactief aanbieden van hiv-tests in gebieden waar de hiv-prevalentie hoger is dan 2 per 1000 inwoners. Het voordeel is dat de hiv-test in deze nieuwe strategieën niet langer gekoppeld is aan seksueel risicogedrag of etniciteit, wat ertoe kan bijdragen dat hij genormaliseerd wordt.AbstractJoore IK, Op de Coul ELM, Bom BCJ, van Sighem AI, Geerlings SE, Prins JM, van Bergen JEAM. Proactive HIV testing required. Huisarts Wet 2017;60(1):24-6. Approximately 1000 patients are diagnosed with HIV in the Netherlands annually. In 2014, 44% of newly diagnosed patients presented relatively late in the disease course. Early detection and treatment of HIV infection is beneficial not only for the individual but also for public health. Thus early detection is essential, but to date HIV testing of high-risk groups has not halted the progress of the epidemic in the Netherlands. Two new strategies have been proposed, besides the testing of risk groups: 1) offering HIV testing to all individuals with HIV indicator conditions, and 2) routinely offering HIV testing in primary care settings where the HIV prevalence exceeds 2/1000 residents between 15 and 59 years. The advantage of both strategies is that HIV testing is not associated with risky sexual behaviour or with ethnicity, which could contribute to testing acceptance.

Vaginal high-risk human papillomavirus infection in a cross-sectional study among women of six different ethnicities in Amsterdam, the Netherlands: the HELIUS study

Objective In the Netherlands the incidence of cervical cancer is higher among ethnic minority populations compared with the general Dutch population. We investigated the prevalence of, and risk factors associated with, vaginal high-risk human papillomavirus (hrHPV) infection in women of six different ethnicities living in Amsterdam. Methods For this cross-sectional study we selected women aged 18–34 years old of six ethnicities from the large-scale multiethnic HEalthy LIfe in an Urban Setting study. Self-collected vaginal swabs were tested for HPV DNA and genotyped using a highly sensitive PCR and reverse line blot assay (short PCR fragment (SPF)10-PCR DNA enzyme immunoassay/LiPA25-system version-1, delft diagnostic laboratory (DDL)). Participants completed a questionnaire regarding demographics and sexual behaviour. Logistic regression using generalised estimating equations was used to assess risk factors of hrHPV, and to investigate whether prevalence of hrHPV differed among ethnicities. Results The study population consisted of 592 women with a median age of 27 (IQR: 23–31) years. Dutch and African Surinamese women reported the highest sexual risk behaviour. HrHPV prevalence was highest in the Dutch (40%) followed by the African Surinamese (32%), Turkish (29%), Ghanaian (26%), Moroccan (26%) and South-Asian Surinamese (18%). When correcting for sexual risk behaviour, the odds to be hrHPV-positive were similar for all non-Dutch groups when compared with that of the Dutch group. Conclusions We found an overall higher hrHPV prevalence and higher sexual risk behaviour in the native Dutch population. Further research is needed to unravel the complex problem concerning cervical cancer disparities, such as differences in participation in the cervical cancer screening programme, or differences in clearance and persistence of hrHPV.

Screening for genital chlamydia infection (Protocol)

This is the protocol for a review and there is no abstract. The objectives are as follows: To assess the effects and safety of chlamydia screening in pregnant and non-pregnant women and in men, compared with standard care, on chlamydia transmission and on complications of infection.

Attitude and practice of Dutch GPs concerning partner notification and treatment for chlamydia.

Introduction: Chlamydia prevalence remains high despite scaled-up control efforts and recurrent infection frequently occurs. Objective: We investigated the potential of direct partner treatment for chlamydia related to current practice and attitude of GPs towards partner notification (PN) and partner treatment (PT). Methods: Four data-sources were combined. 1) Information on current practice via two short questionnaires at a national GP conference. 2) GPs’ attitudes towards PN/PT were explored in a vignette questionnaire study among GPs in NIVEL Primary Care Database (NIVEL-PCD). 3) Quantitative data on (potential) PT were obtained from prescriptions in electronic patient data of NIVEL-PCD. 4) GP recorded questionnaires related to STI consultations in the sentinel practices of NIVEL-PCD. Results: Questionnaires showed that the large majority of GPs (>95%) discuss PN of current and ex-partner(s) with chlamydia-patients. Usually, GPs leave further steps to the patients (83%); partners are rarely treated directly (4%), except when partners are registered in the same practice (16%). In the vignette study, 16-20% of GPs indicated willingness to provide direct PT, depending on patient/partner profile, and 24-45% if possible after patient-initiated PN. Prescription data showed that double dosages of Azithromycin were prescribed in 1-2% of cases. STI consultation data revealed PT in 6/100 cases, via partner prescription or double doses for the index. Conclusions: At present, GPs in the Netherlands rarely treat partners of chlamydia cases directly, except for partners registered in the same practice. GPs may be open to options for direct PT, provided there are clear guidelines to arrange this adequately. Key messages: •At present, GPs in the Netherlands rarely treat partners of chlamydia cases directly, except for partners registered in the same practice. •GPs may be open to options for direct PT, provided there are clear guidelines to arrange this legally and practically. (aut. ref.)

P3.024 Comparison of Chlamydia Trachomatis Antibodies in Vaginal Mucosa and Serum in Women a Fertility Clinic and an STI-Clinic

Background The common asymptomatic nature of Chlamydia infections and consequential PIDs plus the delayed appearance of any damaging effect thereof on the reproductive tract hamper timely interventions for individuals prone to complications. In infertile women, Chlamydia antibodies in serum relate to tubal pathology and lower conception rates. The current ‘proof of principle study’ aimed to assess whether Chlamydia antibodies are detectable in easier, non-invasive vaginal mucosa samples, and if these could predict the risk for complications. Patients and Method We compared outcomes of Chlamydia antibody tests in serum and vaginal swabs in two groups: (a) 77 women attending a fertility clinic, of whom 25 tested positive for anti-chlamydia IgG in serum and (b) 107 women visiting an STI centre, including 30 Chlamydia PCR-positive subjects. The presence of IgG/IgA antibodies was compared (Kappa-test) and determinants investigated (regression). Results In women in the STI clinic, active Chlamydia infections were linked to both IgG and IgA antibodies in serum (p < 0.001) and IgA in vaginal mucosa (p < 0.001), but not IgG in mucosa; mucosa-IgA correlated with IgG in serum (p = 0.001). In women in the fertility clinic, IgG in vaginal mucosal material had a stronger correlation with IgG in serum (p = 0.02) than IgA in mucosa (p = 0.06). Women with tubal pathology or Chlamydia history more commonly had IgG in serum and IgA in vaginal mucosa (both p < 0.001), whereas this link was weaker for mucosa-IgG (p = 0.03); for tubal pathology alone mucosa-IgA had a higher Kappa than serum-IgG (0.41 versus 0.36). Discussion Chlamydia IgG/IgA are detectable in vaginal mucosal material. IgG antibodies in serum had stronger associations with current or past Chlamydia infections. However, IgA antibodies in vaginal mucosa also showed associations with (past) infection and complications. IgA presence in vaginal mucosa might indicate an on-going hidden Chlamydia infection in the upper genital tract, and warrants further epidemiological studies.