Background Since 2000, there has been a marked rise in acute hepatitis C virus (HCV) in HIV-positive men who have sex with men (MSM). We conducted an international phylogenetic study to investigate the existence of an HCV transmission network among MSM. Methods HIV-positive MSM diagnosed with recent HCV (n=226) in England (107), Netherlands (58), France (12), Germany (25) and Australia (24) between 2000 and 2006 were enrolled into a molecular phylogenetic study. Using real-time PCR, the NS5B region of the HCV genome (436 bp) was amplified, sequenced and compared with unrelated NS5B sequences. Results NS5B sequences were obtained from 200 (89%) cases. Circulating HCV genotypes were 1a (59%); 4d (23%), 3a (11%), 1b (5%), and 2b/c (3%). Phylogenetic analysis revealed 156 (78%) sequences that formed 11 clusters (bootstrap value >70%) containing between 4 and 37 individual sequences. Country mixing was associated with larger cluster size (17 vs 4.5 sequences; p=0.03). ‘Molecular clock’ analysis indicated that the majority (85%) of transmissions occurred since 1996. Discussion Phylogenetic analysis revealed a large international network of HCV transmission among HIV-positive MSM. The rapid spread of HCV among neighboring countries is supported by the large proportion (74%) of European MSM infected with an HCV strain co-circulating in multiple European countries; the low evolutionary distances among HCV isolates from different countries; and the trend toward increased country mixing with increasing cluster size. Temporally, this epidemic coincides with the introduction of highly active anti-retroviral therapy and associated increases in sexual risk behaviors. International collaborative public health efforts are needed to mitigate HCV transmission among this population.

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.

We revealed an outbreak of LGV proctitis among MSM in The Netherlands. The ulcerous character favors transmission of HIV, other STDs, and blood-borne diseases. From a public health perspective, it seems important to increase the awareness of possible LGV in MSM with symptomatic proctitis.

A cluster of acute HCV infection is reported among mostly HIV-positive MSM, with multiple partners throughout Europe. Sexual techniques potentially leading to mucosal damage (fisting), concomitant STDs such as LGV and drug use seem facilitating factors for spread. Extensive case finding and partner tracing is advocated as well as targeted prevention messages.

Objective To evaluate the effectiveness of register based, yearly chlamydia screening.Design Controlled trial with randomised stepped wedge implementation in three blocks.Setting Three regions of the Netherlands: Amsterdam, Rotterdam, and South Limburg.Participants 317 304 women and men aged 16-29 years listed on municipal registers at start of trial.Intervention From March 2008 to February 2011, the Chlamydia Screening Implementation programme offered yearly chlamydia screening tests. Postal invitations asked people to use an internet site to request a kit for self collection of samples, which would then be sent to regional laboratories for testing. Treatment and partner notification were done by the general practitioner or at a sexually transmitted infection clinic. Main outcome measuresPrimary outcomes were the percentage of chlamydia tests positive (positivity), percentage of invitees returning a specimen (uptake), and estimated chlamydia prevalence. Secondary outcomes were positivity according to sex, age, region, and sociodemographic factors; adherence to screening invitations; and incidence of self reported pelvic inflammatory disease. ResultsThe participation rate was 16.1% (43 358/269 273) after the first invitation, 10.8% after the second, and 9.5% after the third, compared with 13.0% (6223/48 031) in the control block invited at the end of round two of the intervention. Chlamydia positivity in the intervention blocks at the first invitation was the same as in the control block (4.3%) and 0.2% lower at the third invitation (odds ratio 0.96 (95% confidence interval 0.83 to 1.10)). No substantial decreases in positivity were seen after three screening rounds in any region or sociodemographic group. Among the people who participated three times (2.8% of all invitees), positivity fell from 5.9% to 2.9% (odds ratio 0.49 (0.47 to 0.50)). RESEARCHConclusions There was no statistical evidence of an impact on chlamydia positivity rates or estimated population prevalence from the Chlamydia Screening Implementation programme after three years at the participation levels obtained. The current evidence does not support a national roll out of this register based chlamydia screening programme.Trial registration NTR 3071 (Netherlands Trial Register, www. trialregister.nl). IntroductionChlamydia screening has been promoted as a means of controlling sexual transmission of Chlamydia trachomatis (chlamydia), [1][2][3] which is the most common notifiable infection in some high income countries.1 Before introducing a screening programme there should be evidence from high quality randomised controlled trials that the screening programme is effective in reducing mortality or morbidity. 4 The goals of chlamydia screening are to detect and treat asymptomatic infections, to limit ongoing transmission in the community, and to reduce the incidence of pelvic inflammatory disease.5 Pelvic inflammatory disease results from microorganisms, including C trachomatis, ascending to the upper genital tract and is a strong risk fact...

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.

BackgroundImplementing Chlamydia trachomatis screening in the Netherlands has been a point of debate for several years. The National Health Council advised against implementing nationwide screening until additional data collected from a pilot project in 2003 suggested that screening by risk profiles could be effective. A continuous increase in infections recorded in the national surveillance database affirmed the need for a more active approach. Here, we describe the rationale, design, and implementation of a Chlamydia screening demonstration programme.MethodsA systematic, selective, internet-based Chlamydia screening programme started in April 2008. Letters are sent annually to all 16 to 29-year-old residents of Amsterdam, Rotterdam, and selected municipalities of South Limburg. The letters invite sexually active persons to login to http://www.chlamydiatest.nl with a personal code and to request a test kit. In the lower prevalence area of South Limburg, test kits can only be requested if the internet-based risk assessment exceeds a predefined value.ResultsWe sent invitations to 261,025 people in the first round. One-fifth of the invitees requested a test kit, of whom 80% sent in a sample for testing. The overall positivity rate was 4.2%.ConclusionsThis programme advances Chlamydia control activities in the Netherlands. Insight into the feasibility, effectiveness, cost-effectiveness, and impact of this large-scale screening programme will determine whether the programme will be implemented nationally.

Based on clinical and laboratory surveillance data, trends in the incidence rates of genital Chlamydia trachomatis infections in Sweden between 1991 and 1999 were analysed according to age group and sex. The influence of changes in laboratory methods on the reported infections was assessed. After a decrease in the incidence rate of infection of 36% between 1991 and 1994, followed by a period of stability, a 20% increase was observed between 1997 and 1999 (from 157 to 189/100,000). Between 1991 and 1999 the female:male ratio decreased from 1.7 to 1.4. Incidence rates started to increase in 1994 in the 15-19 y age group for both sexes. Crude Chlamydia positivity increased from 4.1% (352,050 people tested) in 1994 to 5.4% (305,946 people tested) in 1999. This increase in Chlamydia positivity was seen both in laboratories that had changed to more sensitive methods and in those that had not. Changes in laboratory methods can therefore only partially explain the increase in notified cases. Increased screening of men may have contributed to the increase, but rising incidence rates in all young age groups of both sexes suggest a true increase in prevalence.