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Background The majority of Chlamydia trachomatis (CT) infections in men who have sex with men (MSM) are extra-genital. The pharynx is a common reservoir for CT in MSM and might enable ongoing transmission. This study provides an overview of pharyngeal CT in MSM by describing its prevalence, occurrence relative to other genital and rectal anatomic sites, and risk factors by using routine universal testing data. Methods Routine universal testing (defined as >85% tested pharyngeally per clinic-year) surveillance data from all Dutch STI clinics between 2008 and 2017 were used (n=185,253). Multivariable generalized estimating equations (GEE) analyses were used to assess independent risk factors for pharyngeal CT and isolated pharyngeal CT. Results Routine universal oropharyngeal testing was performed in 77.2% (185,253/240.007) of all MSM consultations. Pharyngeal CT was found in 1.2% (95%CI 1.1–1.2; 2,041/176,895) of routinely universally tested MSM. Pharyngeal CT comprised 11.1% (2,041/18,380) of all CT infections. The proportion isolated pharyngeal CT (without concurrent anogenital infection) was 43.9% (897/2,041); 42.7% were concurrent anorectal infections; 8.3% were concurrent with both anorectal and urogenital infections; and 5% were concurrent urogenital infections. Independent risk factors for isolated pharyngeal CT were young age ( 4), being notified for any STI and having concurrent anorectal N. gonorrhoeae. Discussion Routine universal pharyngeal CT testing in MSM is widely implemented in Dutch STI clinics. The relative high proportion of isolated pharyngeal CT might argue for routine universal testing. However, the low prevalence of pharyngeal CT, probably limited public and clinical health impact and risks of overtreatment should be taken into account when determining the benefit-to-risk ratio of testing and treating all pharyngeal CT in MSM.

Background In the Netherlands, general practitioners (GPs) diagnose 79% of STIs and 36% of HIV infections, but opportunities for earlier HIV diagnosis are being missed in primary care. We assessed changes in GPs’ HIV testing behaviour following an educational intervention using competitive feedback, to improve HIV testing in primary care in Amsterdam. Methods The educational intervention, open for all Amsterdam GPs, was implemented from 2015 to 2020. The mean annual number of HIV tests per GP from 2011–2019 was calculated using data from diagnostic laboratories for primary care, and stratified by 4-digit postal code (PC4). Questionnaires and semi-structured interviews were conducted to identify perceived barriers and facilitators to HIV testing. Results In total, 229 GPs (42%) participated in the educational intervention. Participation varied per PC4 area (median 27%, IQR 0%-60%). At baseline, the mean annual number of HIV tests per GP was similar for participants versus non-participants (26.8 versus 24.7, respectively). The number of tests per GP declined from 2011 to 2014 from 29.5 to 20.7, and increased thereafter to 27.1 in 2019. Testing was highest in PC4 areas with highest HIV prevalence. Qualitative analyses revealed various barriers to HIV testing, including taboo and stigma, a shrinking epidemic, and financial barriers. The use of competitive feedback was perceived as a motivator to improve testing behaviour. Of 59 GPs that completed the questionnaire, 68% stated the programme provided eye-openers, and 72% declared it improved their HIV testing behaviour. Conclusion The observed increase in HIV testing coincided with the implementation of our intervention, but there was marked heterogeneity, with testing seemingly associated with local HIV prevalence. Amsterdam is well on its way towards zero new hiv infections, but it will be challenging to keep GPs engaged in proactive testing to prevent late presentations and missed opportunities for HIV diagnosis in primary care.

Background General practitioners (GPs) and sexual health centres (SHCs) are the main providers of STI and HIV testing in the Netherlands. We compared HIV testing by GPs versus SHCs to gain insight in strategies to improve HIV testing, stimulating timely HIV diagnosis. Methods Laboratory data (2011–2018) on HIV testing by GPs and SHCs in five Dutch regions with varying levels of urbanisation were used. Mean regional HIV testing rates per 10,000 residents ≥15 years were compared between providers using negative binomial generalised additive models, and additionally stratified by sex and age (15–29y, 30–44y, 45–59y, ≥60y). Chi-squared tests were used to compare percentage positive between providers. Results Analysed data included 507,197 HIV tests (GP 36%, SHC 64%). The highest HIV testing rates and positivity were observed in highly urbanised regions, with large variation between regions. The HIV testing rates ranged from 28–178/10,000 residents by GPs and from 30–379/10,000 residents by SHCs. Testing rates by GPs were lower than by SHCs in two regions, while these rates were comparable in the others. In all regions, men were tested less by GPs than by SHCs; for women this varied per region. Among 15–29 year olds, GPs’ testing rates were lower than SHCs’, while this was reversed in older age categories. The overall mean HIV positivity was 0.5% for GPs and 0.4% for SHCs. In Amsterdam, positivity was higher among individuals tested by GPs, but in the other regions no difference was observed. Conclusion This is the first study comparing HIV testing by GPs versus SHCs using laboratory data in the Netherlands. Our results show that besides SHCs, GPs also play a key role, especially in some subgroups, but large regional variation exists. Regional-specific interventions to improve GPs’ HIV testing practices are needed for populations not attending the SHCs to ensure timely HIV diagnosis.

Background Indicator condition (IC) guided testing for HIV is an effective way to identify undiagnosed people living with HIV, but studies suggest its implementation is lacking. This systematic review provides an overview of the adoption of IC-guided testing in Western countries. Methods Seven ICs were selected: tuberculosis (TB), malignant lymphoma, hepatitis B, hepatitis C, cervical/vulvar carcinoma/intraepithelial neoplasia grade 2+ (CC/CIN2+, VC/VIN2+), and peripheral neuropathy (PN). Embase and Ovid MEDLINE were searched up to November 20th, 2020. Publications of all types, using data from ≥2009, reporting on HIV test ratios in patients ≥18 years in all settings in Western countries were eligible. HIV test ratios and positivity were reported per IC. A random effects-model for proportions was used to calculate estimated proportions (ES) with 95% CIs. This study was registered at PROSPERO, registration number CRD42020160243. Findings Fifty-seven references, including 23 full-text articles and 34 other publications were included. Most (28/57) reported on HIV testing in TB. No reports on HIV testing in VC/VIN2+ or PN patients were eligible for inclusion. Large variation in HIV test ratios was observed between and within ICs, resulting from different testing approaches. Highest HIV test ratios (pooled ratio: 0·72, 95%CI 0·63–0·80) and positivity (0·05, 95% CI 0·03–0·06) were observed among TB patients, and lowest among CC/CIN2+ patients (pooled ES test ratio: 0·12, 95%CI 0·01–0·31, positivity: 0·00, 95%CI 0·00–0·00). Interpretation IC-guided HIV testing is insufficiently implemented in Western countries. The large variation in test ratios provides insight into priority areas for implementing routine IC-guided HIV testing in the future. Funding HIV Transmission Elimination in Amsterdam (H-TEAM) consortium and Aidsfonds (grant number P-42,702).

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.

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.

Joore 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 patienten (44%) gebeurt dat relatief laat in het ziektebeloop. Vroegtijdige behandeling van hiv na diagnose heeft grote voordelen, voor de patient en 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 teststrategieen, naast het testen binnen risicogroepen, zijn het aanbieden van hiv-tests aan patienten 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 strategieen niet langer gekoppeld is aan seksueel risicogedrag of etniciteit, wat ertoe kan bijdragen dat hij genormaliseerd wordt.

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.)

To map regions of the Netherlands with high HIV prevalence for surveillance and prevention purposes.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).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.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.

Seksueel overdraagbare infecties zijn onlosmakelijk verbonden met seksueel verkeer. Dit hoofdstuk beschrijft de soa-epidemiologie en enkele veelvoorkomende misvattingen rondom seksualiteit en soa. Teneinde adequate diagnostiek, behandeling en voorlichting te kunnen geven, is open communicatie over seksualiteit en seksueel gedrag in de ‘spreek’kamer een eerste vereiste.

BACKGROUND: The majority of Chlamydia trachomatis infections in women are asymptomatic, but may give rise to pelvic inflammatory disease (PID) and tubal infertility. Screening programmes aim at reducing morbidity in individuals by early detection and treatment, and at decreasing the overall prevalence of infection in the population. A number of modelling studies have tried to calculate the threshold prevalence of chlamydia lower genital tract infection above which screening becomes cost-effective. There is considerable debate over the exact complication rates after chlamydia infections, and more precise estimates of PID and tubal infertility are needed, for instance to be inserted in economic models.METHODS: With reference to key studies and systematic reviews, an overview is provided focusing on the epidemiology of chlamydia infection and the risk-estimates of its late complications.RESULTS: In the literature, the generally assumed risk of developing PID after lower genital tract chlamydia infection varies considerably, and is up to 30%. For developing tubal infertility after PID the risks are 10-20%. This implies that the risk of test-positive women of developing tubal infertility would range between 0.1 and 6%. We included chlamydia IgG antibody testing in a model and estimated a risk of tubal infertility up to 4.6%.CONCLUSION: The risk of developing late complications after chlamydia lower genital tract infection appears low. High quality RCTs dealing with the transition from cervicitis to infertility are needed to broaden the evidence. In screening programmes, chlamydia antibody testing, as an intermediate marker for potential adverse sequelae, might enable more precise estimates.

Infectie met Chlamydia trachomatis (CT) is de meest frequent voorkomende bacteriele soa in Nederland. CT-infecties zijn een belangrijke oorzaak van ontstekingen in het kleine bekken, infertiliteit, buitenbaarmoederlijke zwangerschap en chronische buikpijn bij vrouwen. Zeventig procent van de infecties bij vrouwen en 50% bij mannen verloopt zonder specifieke symptomen. Huidige testmethoden middels amplificatietechnieken maken een screeningsprogramma via thuis verzamelde monsters mogelijk. In 2008 is gestart met een proefimplementatie om meer inzicht te krijgen in haalbaarheid, effectiviteit en impact.

Contains fulltext : 170977.pdf (Publisher’s version ) (Open Access) 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.

Background: In some European countries telephone triage (TT) during out-of-hours primary care showed to be safe and effective. Other countries, such as Belgium, may not have trained auxiliary personnel while their national health services want to establish TT. Objectives: To compare urgency levels assessed by secretaries and general practitioners in one general practice cooperative in Belgium. Methods: Percentage of correct-, under-, and over-triage were calculated in total and per reason for encounter. Inter-rater agreement was investigated. Results: The secretaries correctly triaged (same urgency level) 77% of the telephone calls, under-triaged 10% and over-triaged 13%.'Shortness of breath', 'skin cuts', 'chest pain', 'feeling unwell' and 'syncope' were often under-triaged. Conclusion: Before introducing TT, auxiliary staff should be trained and protocols should be used.

De huisarts speelt een belangrijke rol in de informatieverstrekking aan jongeren over seksualiteit en seksuele gezondheid, en over seksueel overdraagbare aandoeningen en de preventie en eventuele behandeling ervan. Tijdens het spreekuur doen zich vele geschikte momenten voor om op deze onderwerpen in te gaan. Bij directe vragen over anticonceptie en de morning-afterpil en bij vragen en klachten die verband houden met soa. Zeker voor jongeren en adolescenten geldt dat seksuele gezondheid een wezenlijk onderdeel vormt van de totale gezondheid. Van de huisarts wordt in dit verband de proactieve, open houding en gepaste aandacht verwacht zoals die wordt geadviseerd in de nhg-Standaard Het soa-consult.adolescenten soa seksualiteit allochtonen

Infectie met Chlamydia trachomatis is de meest voorkomende bacteriele soa in Nederland. Opstijgende C. trachomatis-infecties zijn een belangrijke oorzaak van pelvic inflammatory disease, infertiliteit, buitenbaarmoederlijke zwangerschap en chronische buikpijn bij vrouwen. Diagnostiek geschiedt met zeer gevoelige amplificatietechnieken. Een ongecompliceerde C. trachomatis-infectie worden behandeld met 1 gram azitromycine. Gecompliceerde infecties, zoals pelvic inflammatory disease en epididymitis vergen een langere kuur en verschillende antibiotica. Zeventig procent van de infecties bij vrouwen en 50% bij mannen verloopt zonder specifieke symptomen. Onder personen van vijftien tot veertig jaar in de huisartspraktijk in Amsterdam bedroeg de C. trachomatis-prevalentie tussen 2,6 en 4,8%. Bij jonge vrouwen en bij Surinaams-Antilliaanse personen werden aanzienlijk hogere prevalenties gevonden. Actiever opsporen van C. trachomatis-infecties (en andere soa) onder risicogroepen wordt aangeraden. Voorlichting en partnerwaarschuwing zijn integraal onderdeel van het soa-consult.

Infectie met Chlamydia trachomatis (ct) is de meest frequent voorkomende bacteriele soa in Nederland. ct-infecties zijn een belangrijke oorzaak van pid, infertiliteit, buitenbaarmoederlijke zwangerschap en chronische buikpijn bij vrouwen. Zeventig procent van de infecties bij vrouwen en 50% bij mannen verloopt zonder specifieke symptomen. Onder personen van 15 tot 40 jaar in de huisartspraktijk in Amsterdam bedroeg de ct-prevalentie tussen 2,6 en 4,8%. Bij jonge vrouwen en bij Surinaamse/Antilliaanse personen werden aanzienlijk hogere prevalenties gevonden. Actiever opsporen van ct-infecties onder risicogroepen wordt aangeraden. Voor de invoering van grootschalige, nationale periodieke ct-screening ontbreken vooralsnog prevalentiegegevens buiten Amsterdam en zijn er nog maar slechts in zeer beperkte mate gerandomiseerde interventiestudies van voldoende kwaliteit beschikbaar die preventie van complicaties aantonen.

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 >= 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.

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.

A spinal epidural abscess (SEA) is an uncommon condition, appearing in 0.22 cases per 10 000 hospital admissions. Urgent surgical decompression in combination with long term antibiotics is the common treatment of choice for SEA. However, in some cases, a non-surgical treatment can also be considered. In this case report, a patient is presented with SEA extending from C2 to L3 which was successfully treated with antibiotic therapy without surgical intervention.

A 65-year-old man with weight loss, a 65-year-old Surinam woman with dyspnoea, and a 55-year-old lesbian woman suffering from painful joints, weight loss and diarrhoea were eventually diagnosed as being infected with HIV. At the time of diagnosis, all three patients had CD4 counts below 100 cells x 10(6)/l and had presented with aids defining symptoms. In the Netherlands, an estimated 40% of people infected with HIV do not know about their HIV status. Earlier recognition would reduce morbidity and mortality and furthermore, reduce transmission of the virus. For this reason we advocate routine HIV testing for all persons belonging to a population with an HIV prevalence above 0.2% but also for all patients presenting with unresolved chronic complaints, irrespective of HIV risk factors.

The practice guideline on STD consultations from the Dutch College of General Practitioners sets out guidelines for the diagnosis and treatment of Chlamydia-infection, gonorrhoea, syphilis, trichomoniasis, genital herpes condylomata acuminata, hepatitis B, HIV-infection and pubic lice. Testing for Chlamydia-infection is always indicated if an STD is suspected but the necessity of also testing for gonorrhoea, syphilis, hepatitis B or HIV-infection depends on the likely risk. For the diagnosis of Chlamydia in a symptomatic woman it advises taking material from the cervix and urethra. In an asymptomatic woman Chlamydia infection is excluded by means of a urine test. In men a urethral swab of the first part of the urinary stream can be used for diagnosis. The first choice of treatment for gonorrhoea is a single 1 g intramuscular dose ofcefotaxime. The practice guidelines also examine other aspects of treatment for STDs including counselling and telling partners.

To determine the rate of PID in women with genital Chlamydia trachomatis infection.Systematic literature review.MEDLINE and EMBASE were searched over the years 1975-2003 using the keywords 'Chlamydia trachomatis', 'complication', 'pelvic (inflammatory disease)', 'PID', 'endometritis', 'adnexitis', and 'salpingitis'. The reference lists ofthe articles retrieved were checked for other relevant publications. The PID complication rate was determined, as were the characteristics of the study populations and the validity of the diagnostic methods and outcome measures used.9 prospective studies were identified. The rate of PID in women with a genital C. trachomatis infection varied between o and 72%. Asymptomatic women who were diagnosed with C. trachomatis infection in general screening had the lowest rate of PID: 0-4%. PID occurred in 12-30% of symptomatic women or women with a higher risk of having an STD (e.g. visitor of an STD clinic, double-infection with gonorrhoea, high risk assessed by questionnaire, having a partner with symptomatic C. trachomatis infection). Women who underwent legal abortion had the highest rate of PID (27-72%).The PID rate in women with C. trachomatis varied considerably. Risk depended on whether the infection was symptomatic and the prior probability of having an STD.

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.

The Dutch Institute for Health Care Improvement revised guideline, 'Sexually transmitted diseases and neonatal herpes' summarises the current scientific position on the diagnosis and treatment of a great number of sexually transmitted diseases (STD) and neonatal herpes. Symptomatic treatment of suspected Chlamydia trachomatis infection and gonorrhoea without previous diagnosis is not recommended. Treatment can be started immediately, once samples have been taken. Risk groups eligible for screening or proactive testing on C. trachomatis infection include: partners of C. trachomatis-positive persons, visitors of STD clinics, women who will undergo an abortion, mothers of newborns with conjunctivitis or pneumonitis, young persons of Surinam or Antillean descent, young women with new relationships and individuals whose history indicates risky sexual behaviour. A period of 3 months can be adopted between a risky contact and the HIV test (this used to be 6 months), unless post-exposure prophylaxis was used. For the treatment of early syphilis no distinction is drawn between HIV-infected and non-HIV-infected persons. It is no longer recommended that women in labour with a history of genital herpes are tested for the herpes simplex virus. Virological testing of the neonate is only advised if the mother shows signs of genital herpes during delivery.

Background The role of primary care in STI-control has long been neglected. Although national STI surveillance often thrives on data of STI-Clinics, recent research in the Netherlands shows that approximately 70% of all STI-related consultations are in General Practice (GP). More attention for sexual health in primary care is warranted. Methods In 2004 the Dutch College for Family Physicians (NHG) added a guideline about the “STI consultation” to their list of GP certified “standards of care”. The guideline describes care for patients with complaints of STI, for patients with questions about STI (test request), and also describes pro-active testing policies for persons visiting the health centre for a not-STI related reason. The guideline is currently being updated. Implementation of the guideline is facilitated by regional “expert” GP, united in the GP-advisory group on STD, HIV and Sexuality (the Expert group Sexual Health (SeksHAG). Such Expert Groups within the GP institutional body are relatively new and also exist, for example, diabetes and Asthma/COPD. Results Annually approximately 1500 GP receive a continuous education session on STI facilitated by the GP expert in their region. Previous research showed moderate impact on testing habits and case detection. Qualitative interviews describe insight in personal barriers as a positive gain in training sessions. Prescribing habits of GP for Gonococcal infections are legging behind, half of GP prescribing ciprofloxacin, for which resistance is well above 40%. Discussion A substantial but often hidden proportion of STI consultations take place in general practice. More interventions on STI-care in GP are recommended. An expert group within the national GP body can enhance attention for quality of care. The new emerging paradigm within primary care to focus not only on disease (pathogenesis) but also on health (salutogenesis) might open new avenues for sexual health counselling. New technology also has potential: continuous education sessions have limited impact on prescribing habits for infrequent conditions with fast changing resistance patterns like gonoccocal infections; learning GP to use more and better their electronic prescription expert-system based on patient ICPC code (Prescriptor) is a better option and now available in most GP operating systems in the Netherlands.

Background In 2005, STI centres in the Netherlands started provider-initiated HIV testing policy, in order to decrease the proportion of people unaware of their positive HIV status and to enable interruption of transmission and create more opportunities for timely treatment. This policy gradually evolved towards opt-out HIV testing and in January 2010, this became the official policy within all Dutch STI centres. The effects of the change in HIV test policy were studied and factors associated with opting out for HIV testing were identified. Methods Data from January 2004 to June 2010 from 488 727 consultations registered in the Dutch national surveillance in the STI centres were used to characterise current practices on HIV testing. Known HIV positives were excluded from analyses. Logistic regression analyses were done separately for men having sex with men (MSM) and heterosexuals, to identify factors associated with refusing an HIV test. Results Since 2004, the percentages of HIV testing within an STI consultation have increased significantly from 56% up to 92% in 2009, and further to 97% in the first half of 2010 when opting out was implemented nationally (both p Conclusions Although provider-initiated HIV testing already increased HIV testing rates, national implementation of opting out for HIV testing increased this uptake even more. Standard testing on HIV in every STI clinic is shown to be highly feasible and effective. In order to optimise the opt out policy, and thereby successful interruption of HIV transmission, interventions to motivate “opt-outers” should be studied, since the few clients still refusing an HIV test were linked to higher risk behaviour.

Background The Chlamydia Screening Implementation (CSI) is a Dutch large-scale pilot of an internet-based self-sampling Chlamydia trachomatis (Ct) screening program for 16–29-year-old men and women. The effectiveness of CSI can be estimated from changes in the positivity rate of the sampled individuals, but shifts in health-care use and CSI participation rates makes modelling a valuable alternative approach for estimating screening effectiveness. Methods We simulated the spread of Ct in a heterosexual population of age 13–65, using sexual survey data to parametrise a dynamic sexual contact network. A screening program was implemented in the model by constructing “participation trees”, which capture the likelihood to participate given an individuals participation history, as observed in the CSI program. Currently available health-care options to test for and treat Ct were also implemented in the model as a baseline (including trends in their usage), against which the effect of screening could be compared. In order to estimate the long-term effects of screening on the Ct prevalence in the Netherlands, future participation rates were estimated from trends in the yearly number of new participants, and by extrapolation of the participation trees. Results Compared to a baseline scenario, there is a moderate additional effect of 3 years of screening: the estimated Ct prevalence for the target population (16–29) dropped from 2.8% to 1.7% in large cities, and from 1.9% to 1.2% in more rural regions. As repeated invitees were likely not to participate, the largest effect of screening occurred in its first year when everyone in the target population was invited for the first time. After 3 years, the largest effect of screening on the Ct prevalence had been reached. Due to the anticipated further decrease in participation rates the long-term decrease in Ct prevalence is estimated to be in the range of 0.5–0.7 and 0.4–0.6 per cent-points in urban and rural regions, respectively. Conclusions A continued population based screening program has a permanent additional effect on lowering the Ct prevalence in the Netherlands, but the size of this effect is strongly tied to the participation rate in the targeted population. Therefore, the accuracy of long-term predictions of screening effectiveness depends on a good model implementation of the available data on participation behaviour.

Background A register- and Internet-based chlamydia screening started in 2008 among 16–29 year olds in Amsterdam, Rotterdam and South-Limburg, aiming to reduce population prevalence of chlamydia infections. Automated respondent reminders by letter, email and SMS were used to encourage and optimise participation. The contribution of reminders on package request and sample return was examined in relation to characteristics of the target population. Methods On average, 280 000 persons were annually invited by means of a personal letter. Individuals who did not respond to the invitation letter received a reminder letter after 1 month. Email- and SMS reminders were sent to individuals who requested a test kit and did not return a sample or did not check their test results online. We evaluated the effect of reminders on response and participation rates in two screening rounds. Logistic regression analyses were conducted to identify determinants of providing a GSM number, late response (requesting a test package after a reminder letter), and late participation (returning a sample after email/SMS reminders). Results The overall package request rate in the first round increased from 12% to 20% (see Abstract P2-S8.06 Figure 1) after the reminder letter (in round 2 from 8% to 14%). The proportion of individuals returning a sample increased from 10% to 16% after email/SMS reminders (in round 2 from 7% to 11%). Of all respondents, 99% provided an email address and 72% a GSM number. Factors associated with providing a GSM number were younger age (16–24 yrs), non-Dutch background, lower educational level, symptoms of an STI, and sexual risk behaviour in the past 6 months (p Conclusions Respondents’ willingness to provide an email address or GSM number for communication during the screening procedure was high. Factors associated with providing a GSM number were also related to chlamydia positivity. Automated respondents reminders by letter influenced response rates (package request) and resulted in reaching more people at higher risk. Email- and SMS reminders contributed substantially to participation rates (sample return).

Background The impact of a Chlamydia screening programme can be measured by the incremental amount of Chlamydia tests performed and cases detected as compared to the throughput in regular care. In the Netherlands, regular STI care is provided by specialised STI-centres (aimed at high-risk groups) and General Practitioners (GP9s, basic opportunistic screening and care for symptomatic cases). An annual register-based Chlamydia screening programme is implemented in three regions since 2008. Methods The number of persons tested and cases detected in the Chlamydia Screening among 16–29 year olds in Amsterdam, Rotterdam and South Limburg, 2008–2010, were compared to consultations and diagnoses in this age group reported in surveillance data from STI centres in the regions and estimates of STI care in general practices in these regions, 2007–2010. Round 3 data are based on the first 6 months of the year. Results The baseline testing rates (at STI centers and by GP9s in year pre-screening) were 10% in Rotterdam, 13% in Amsterdam and 6% in South-Limburg. CSI increased testing rates steeply in the first year to 26–30% in the cities and 17% in Limburg; this decreased to 20–21% and 13% in round 3, still doubling testing rates as compared to baseline. Positivity rates at regular STI-care facilities are higher than in CSI: 12–15% in regular care vs 4–5% in CSI; therefore the addition of CSI to case-finding in the three regions was lower than that to testing: the screening programme added about 41% on top of the cases found in regular care in round 1, but this decreased to 20% in round 3 due to lower participation and positivity rates in consecutive rounds. Conclusions By comparison to regular testing at STI centers and in general practice, the Chlamydia Screening had a major contribution towards the number of young people tested for Chlamydia in the three regions. The addition towards case-finding was lower, because the case-detection rate of the screening programme was lower than that in regular care. The Screening programme did not seem to affect the number of patients seen in regular care, but double “consumers” cannot be excluded.

Background Reinfections remain challenging in the control of Chlamydia trachomatis (Ct). In a systematic internet-based Ct Screening programme (CSI) in the Netherlands, all Ct-positive participants automatically received a test kit after 6 months to facilitate discovery of reinfections. Determinants for reinfection for two screening rounds, treatment and partner notification are discussed. Methods CSI-home-based testkits can be requested online after register based postal invitation. Infected participants get a referral letter for their health provider to get treatment for themselves and their current partner; expartners can be alerted by the participant and request a test kit via the website. Participants fill in a questionnaire on sexual behaviour voluntarily. Ct-positives answer questions about treatment and partner notification 10 days after checking their results. Infected participants who do not check their result online receive it by postal letter. After 6 months retest kits are automatically sent to previously infected participants. Results Overall, 3185 participants (4.1%) tested positive; 7% of Ct-positives did not check their result online and received a postal letter. The majority (86%) of Ct-positive participants who answered the treatment questionnaire (response 43%) was treated within 2 weeks after checking their result online; 80% of those with a current relationship reported their partner had also been treated and 16% of those with past relationships notified ex-partners via the website. One third of the ex-partners participated, 28% of whom were Ct-positive. After 6 months, 3055 participants received a retest kit and 66% responded. The reinfection rate was 8.8%. Results of the questionnaire revealed 75% of retest-positives had been treated for the initial infection and 70% had had their partner treated, while these proportions were 87% and 80% among retest-negatives. At higher risk for reinfections were young people ( Conclusions The uptake of retesting was successful counting two third with automatically sent testkits 6 months after screening. Reinfection rates were high, especially among known risk-groups. Questionnaire results show that follow-up of (partner) treatment after Chlamydia infections could be improved.

Background Whereas the majority of STI-related consultations in the Netherlands take place in general practise (GP), national surveillance of STI predominantly uses data from STI centres, focussing at trends in high-risk groups. To also explore determinants of STI in the GP setting, an STI questionnaire was introduced in a nationwide GP-network. Methods Since 2008, GPs of the Dutch Sentinel GP network (45 practises; 125,000 patients) are asked to complete a questionnaire for each STI-related episode, comparable to data collection in STI centres, and report laboratory results. Data included patient demographics, sexual behaviour and sex-life history. Results Annually, for 0.4% of GP patients an STI consultation was recorded, mainly among young heterosexuals of Dutch origin, a profile comparable to STI centre visitors, though specific high-risk groups like MSM and CSW were reported less by GPs. GPs requested one or more laboratory tests in 83% of consultations; an STI was diagnosed in 34%, most frequently chlamydia (21%), condylomata (9%) and herpes (6%). Higher risk profiles were, depending on the STI: 25 years old (syphilis) or having symptoms (any STI). GP guidelines on multiple testing in high-risk groups (5 STI) were rarely fully adhered to, with many missed opportunities to test for HIV in patients with casual sexual contacts or originating from HIV-endemic countries. Discussion STI consultation rates were lower than estimates based on electronic registers, probably due to underreporting. Patients who consulted a GP for STIs were comparable to persons attending STI-centres. Where STI-centres routinely test patients for chlamydia, syphilis, HIV and gonorrhoea, GPs test more selectively, resulting in higher case detection rates. This diverges from national GP guidelines and STI diagnoses may be missed. Opportunities for a more proactive role of GPs in STI and HIV testing should be explored.

Background Register and internet-based Chlamydia Screening Implementation (CSI) was introduced in the Netherlands to detect and treat asymptomatic infections and to limit ongoing transmission through annual testing and treatment of Chlamydia trachomatis (Ct) in young people. This population-based screening may be compromised by addressing individuals who are already covered by regular care like general practitioners and STD clinics. We study, in a timeframe of five years, overlap between CSI participation and attendance of major services offering Ct screening services to assess whether CSI reached additional patients. Methods Data included all Ct tests performed in subjects aged 16–29 years in Eastern South Limburg in the Netherlands (population 16–29 years: 42,000) between 2006 and 2010 by CSI, regional STD clinic, general practitioners (GPs), and specialists (mainly gynaecologists) as reported by the testing laboratory. Data were matched between testing agencies, with complete certainty (STD clinic) (name, date of birth) and with a certainty range (part of the name, month and year of birth). Maastricht University’s ethical committee approved the study. Analyses were restricted to subjects tested (at least) by CSI. Results In CSI, 4477 (82.9%) subjects were first-time testers, others were previously tested by the STD clinic (3.5%, n = 190), GPs (6.4%, n = 352), specialists (3.6%, n = 197) or multiple providers (3.4%, n = 183). Compared to persons previously tested by the STD clinic/GPs/specialists, first time testers were younger (mean age 23y vs. 24y, p Conclusions Chlamydia screening addresses young individuals, including heterosexual men, hidden to current care with similar Ct prevalence and adds to the existing regular care.

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.

Background Chlamydia trachomatis (Ct) reporting rates from sexually transmitted infection (STI) 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 dynamics of the Ct epidemic, we explored the Ct IgG seroprevalence (marker of past Ct infection) in the general population of the Netherlands in 1996 and 2007. Methods From two independent population-based studies in 1996 and 2007, serum samples were drawn, from 650 men and 1,000 women per study. Participants completed a questionnaire covering demographic information and sexual risk factors. Serum antibodies were analysed using Medac CtIgG ELISA test. Multivariate logistic regression analyses explored changes in, and determinants of Ct IgG seroprevalence. Results The Ct IgG seroprevalence was higher in women than in men in 1996 (11.3% vs 5.2%), but this difference had diminished in 2007 (8.4% vs 6.9%). Among women aged 25–40 years, the seroprevalence was significantly lower (OR 0.6 [0.4–0.8]) in 2007 than in 1996, whereas the seroprevalence among women aged 15–24 years and men in both age groups was slightly higher in 2007, though not significantly. Determinants of seropositivity were female gender (OR 1.7 [1.3–2.0]), known history of Ct infection (OR: 3.4 [1.7–6.8]), 25–40 years old (OR 1.6 [1.1–2.4]), non-western ethnicity (OR: 1.8 [1.1–3.2]) and ≥ 2 recent sexual partners (OR: 2.2 [1.4–3.7]). Conclusion Ct IgG seropositivity was associated with known STI risk factors. Our results suggest that the proportion of individuals in the population who have had a Ct infection did not increase between 1996 and 2007. The decrease in seroprevalence among women aged 25–40 years between 1996 and 2007 may indicate changes in Ct transmission due to a more pro-active ‘test and treat’ policy.

Background Among sexually transmitted infections (STIs), Trichomonas vaginalis (TV) is the most common non-viral STI worldwide. However, in Europe, a limited number of studies, mostly on specific risk groups, have described a low TV prevalence. Therefore a large multi-cohort study was performed to investigate the prevalence of TV among three distinct Dutch patient populations. Additionally, the relationship between Chlamydia trachomatis (CT) and TV co-infection was assessed. Methods 2089 participants, men and women, were included between 2008 and 2012 from three distinct cohorts. A total of 575 participants from the population-based national Chlamydia Screening Intervention (CSI) study, 465 attendees of the STI-clinic South Limburg and 602 patients from general practitioners (GPs) were included. An additional number of CT positives (n = 447) was included to assess TV and CT co-infection. All participants were assessed forTV using real-time PCR. Results The overall prevalence of TV was 0.9% among the three distinct cohorts and no significant differences between the 3 study populations were observed (GP patients (1.5%), STI clinic (0.6%) and population-based cohort (0.7%)). TV was found in 0.7% of the CT positives and a similar 1.1% among CT negatives. In contrast to CT prevalence which significantly decreased with increasing age, TV prevalence was highest in the age group > 40 years (2%), but did not differ significantly from other age-groups. Conclusion This large multi-cohort study confirms the low burden for TV in the Netherlands (

Background In the Netherlands 30–40% of HIV-infected persons are not aware of their status. Half of the newly diagnosed present late. Late treatment reduces life expectancy with approximately 10 years. Early treatment reduces transmission to sex partners with 96%. A more proactive role in testing in primary care is advocated. In the Netherlands the GP is the main care provider, also for sexual health. We investigated the trend in HIV-related consultations and testing practises in general practise in the last 2 decades. Methods Within a nationally representative Dutch Sentinel General Practice Network we analysed HIV-related consultations from 1988–2009 using a questionnaire, in which patient’s characteristics, the reason for consulting the GP, interventions and test results were recorded. Trends over time were calculated by multilevel analysis. Results Time trend analyses show an increasing trend in HIV-related consultations and in the total number of HIV tests per 10,000 registered patients. Mean number of consultations doubled from 7 in 1988 to 14 consultations/10.000 population in 2009. Over the whole period, the number of HIV-related consultations was significantly higher in urban areas. The proportion of people high at risk, men who have sex with men (MSM) decreased. The proportion of HIV related consultations initiated by the GP increased from 11% in 1988 to 23% in 2009. Conclusion In this 20-year period the policies around HIV testing changed drastically. HIV-related consultations, as well as provider initiated testing in general practise in the Netherlands increased, however slowly and mainly in low risk groups. Testing rates remain low. To prevent undiagnosed and late presentation of HIV infection, GP need to be more pro-active. New and innovative avenues, like opt-out and indicator-based testing, are needed in primary care as many test-opportunities among high risk groups and in high risk areas are missed.

Background Accurate information about the prevalence of Chlamydia trachomatis infections is needed to assess prevention and control measures at national and regional level. Methods Systematic review up to August 2012 of population-based cross-sectional studies that estimated chlamydia prevalence in high income countries, focussing on EU/EEA Member States. Data were extracted about study findings; the risk of bias was assessed and meta-analysis was performed where appropriate. Meta-regression was used to examine the relationship between chlamydia prevalence estimates and study response rates. Results 25 population-based studies were included from 10 EU/EEA countries and 14 studies from 6 other high income countries. Four EU/EEA Member States reported on nationally representative surveys of sexually experienced adults ≤ 26 years, with response rates from 52–71%. Chlamydia point prevalence estimates in 18–24 year olds (3 studies) ranged from 3.0–4.7% in women and from 2.4–4.7% in men. Chlamydia prevalence estimates in EU/EEA countries and other high income countries were statistically consistent. The combined estimate from 5 studies in 18–26 year olds in Europe and the USA was 4.3% (95% CI 3.7, 5.0%) in women and 3.6% (95% CI 2.9, 4.3%) in men. In most studies there was either a high risk of selection bias in the methods used or insufficient information to judge. Estimates of chlamydia prevalence were inversely associated with response rate (p = 0.005 in women, 0.011 in men). Conclusions Selection bias in chlamydia prevalence surveys is likely, with over-estimation of prevalence being more likely than under-estimation. Cross-sectional surveys with lower response rates are associated with higher estimates of chlamydia prevalence. In studies with low response rates the percentage of chlamydia positive tests should not be interpreted as an estimate of population prevalence. Applying standards for the reporting of prevalence surveys might help to improve consistency in future.

Background In cervical cancer screening, uptake of screening is approximately 10% higher if a woman is invited by her General Practitioner (GP) compared to invitation by Municipal Public Health Service (PHS). A large register-based selective Chlamydia Screening Programme is implemented in Amsterdam (Netherlands) since 2008 by the PHS. We wanted to evaluate whether response rates in Chlamydia screening where higher if invitational letters are sent by a persons9 GP and not by PHS. Methods Based on the municipal registers, annually all 140 000 persons in Amsterdam aged 16–29 yr are invited with a postal letter to participate. Further procedures are internet-based: requesting test-packages, obtaining results, even partner-referral, can be realised via the internet and the unique identifier provided in the personal letter. In one part of the city, the Southeast inner-city area, GP-registers of six health centre are matched with the list of invitees extracted from the municipal register. In the invitational letter these matched eligible9s are personally addressed by their GP and not by the physician of the PHS. Participation rates from invitees of GP and PHS in the same geographical town area are compared in three screenings-rounds (r 3 not yet fully completed). Results In these four town area9s in each screening round annually 13 500 persons are invited, of which 35% by the GP and 65% by PHS. In screenings-round 1, the response to invitations by the GP was slightly higher than the response to invitations sent by the PHS in 3 out of 4 neighbourhoods where this was piloted (overall GPs: 16.2% [range: 15.3%–29.1%]; overall PHS: 14.9% [14.4%–21.6%], p=0.023). In round 2 and 3 the difference was not significant (GP vs MHS: r2 10.3%–10.2%; r3 9.5% vs 9.4%). (Abstract O5-S4.01 figure 1). Conclusions In the first screening-round uptake was slightly higher among GP-invited, but this effect was lost in subsequent screening-rounds. Inviting universally via the PHS is logistically easier and yields the same response rate.

Background Achieving adequate levels of participation and capturing high risk groups are key stones for the effectiveness of large-scale Chlamydia screening programs. We examined the determinants of (repeated) participation and Chlamydia positivity to evaluate to what extent high risk groups were reached in a large scale Internet-based screening program in the Netherlands. Methods The Chlamydia Screening Implementation was initiated in three regions among people aged 16–29 years. Data from the first two screening rounds (2008–2010), in which approximately 280 000 persons were invited annually, were analysed. Socio-demographic and behavioural correlates of screening participation and positivity were studied in multilevel logistic regression models. Cluster was added as a second level of analysis, taking into account the effect of the neighbourhood-based invitations (to cover social or sexual networks). Results The same socio-demographic factors associated with lower screening uptake were also associated with higher Ct-positivity such as young age, non-Dutch origin, lower education, high community risk, low SES, in round 1 as well as 2. At the same time, behavioural risk factors such as having casual partners, ≥2 partners in Conclusions Socio-demographic factors associated with lower participation were also associated with higher Ct-positivity, showing that, high-risk demographic groups were more difficult to mobilise than low-risk groups. However, independent of this, higher behavioural risk levels were associated with higher participation rates (especially in the model for repeated participation), suggesting self-selection for screening based on the persons’ risk (perception) in both low and high community risk groups. Our study shows the complexity of the process—including individual as well as community factors and their interaction—as to whether or not be screened for chlamydia.

Background Chlamydia screening programmes can only work when they motivate sufficient persons at risk to get tested regularly. The outcomes of the Chlamydia Screening Implementation (CSI) in the Netherlands are novel and valuable because of the large scale of the programme (315 000 young persons targeted), its systematic nature (invitations based on municipal registers) and its multiple screening rounds (annual invitations in three consecutive years). Methods From April 2008 to March 2010, Chlamydia Screening was offered annually to municipal-registered 16–29 year olds in three regions of the Netherlands. A phased implementation was applied by grouping clusters in three random, risk-stratified blocks. Participation and positivity rates were compared between blocks submitted to 1, 2 or 3 screening rounds (3rd round only partially completed). The effect of the repeated screening rounds on the prevalence of Chlamydia in the whole target group was estimated by weighting procedures comparing demographic characteristics of participants and target group. Results The participation rate in the first round was 16% among all invitees and 20% among the sexually active target population (M13%, F 25%). The participation fell down to 11% in blocks invited two times and 9% in the block invited three times, whereas it was 13% in the control block invited in round two only. The positivity rate in round one was 4.2% among all participants. Positivity rates decreased significantly to 4.0% in blocks screened twice and to 3.5% in the block screened thrice (p=0.04); in the control block 4.3% tested positive. The population prevalence was estimated at 2.6% in Amsterdam, 3.8% in Rotterdam and 2.4% in South Limburg. The prevalence declined over the three screening rounds, but declines were not significant (see Abstract O1-S09.03 figure 1). Conclusions The participation in the CSI project was lower than expected and declined with repeated invitation. Chlamydia positivity rates were reduced by 17% in clusters screened three times, whereas these stayed high in control groups. Only a small and non-significant impact on population prevalence was measured. Further extrapolation of the findings in a simulation model suggest a limited impact on Chlamydia prevalence after 10 years of screening and estimates of cost-effectiveness do not support a nationwide roll-out of this programme in the Netherlands.

In three patients with severe acute cyanide poisoning, a cyanosis was observed instead of the bright pink skin coloration often mentioned as a sign in textbooks. Treatment of cardiopulmonary insufficiency is as essential as antidotal therapy and the use of sodium nitrite and 4-DMAP is not without risk as, in practice, the methemoglobin-level induced is difficult to control.