http://repub.eur.nl/res/aut/8129/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/39101/ 2012-05-14T00:00:00Z Background: Partner notification (PN) among individuals newly diagnosed with HIV/STI is seen as a vital tool to identify others at risk of infection. However, hardly any data are available on the effectiveness of PN on HIV/STI transmission in the Netherlands. This study aims to fill this gap by assessing current PN practices, case-finding effectiveness, and determinants of being notified among men having sex with men (MSM) in the Netherlands.Methods: Nurses from five STI centers participated in a prospective pilot study on PN outcomes (partners being: at risk, notifiable, notified, and tested) for HIV/STI, by completing a newly developed PN registration form (PN database). PN outcomes including case-finding effectiveness (number of newly diagnosed cases in partners/number of partners being tested) for HIV, syphilis, and gonorrhoea were studied among MSM. Furthermore, the national STI database was analyzed to identify determinants of being notified. The number of infections that remained undetected was estimated based on these two databases.Results: In total 105 MSM, newly diagnosed with HIV/STI, reported 612 sexual partners at risk of whom 41% were notifiable and 31% were notified. Patient referral was the predominant PN method (90%). The overall case-finding percentage was 36% (HIV: 15-33%, gonorrhoea: 17-50% and syphilis: 4-11%). Case-finding percentages were lower in the national STI database: 21% (5%, 28%, 12%). Persons with one or more sexual partners, known HIV positives, and IDU were more likely to be notified to the STI clinic. Notified clients were more likely to have HIV/STI than unnotified clients (OR 1.7-2.5). Based on these two databases, an estimated 75 to 133 infections remained undetected (HIV: 12-90; gonorrhoea: 28-97; syphilis: 5-12 infections).Conclusions: Partner notification among MSM in the Netherlands is suboptimal; an extensive number of STI/HIV infections remained undetected mainly due to unnotifiable partners. To enhance PN practices, combined and innovative PN interventions such as Internet-based PN will be implemented for hard-to-reach MSM and other risk groups. http://repub.eur.nl/res/pub/18371/ 2009-03-01T00:00:00Z The transmission of infectious diseases can be traced using epidemiological and molecular information. In the current study, the congruence was assessed between sequence data of the hepatitis B virus (HBV) and epidemiological information resulting from source and contact tracing of patients seen at the Municipal Public Health Service in Rotterdam between 2002 and 2005. HBV genotypes A-G were present in 62 acute and 334 chronic HBV patients. At the sequence level, the identical sequences of members of epidemiological transmission pairs and the rarity of such pairs provided strong support for correctness of the hypothesized transmission routes.The molecular support for epidemiological transmission pairs derived from source and contact tracing was further assessed by using topological constraints in parsimony analyses in agreement with epidemiological information, and by taking the presence of polymorphic sites of HBV within patients into account. This, in principle, allows mutations in epidemiological clusters. Of 22 epidemiological clusters, six could be refuted, four clusters received support from the molecular analysis, and support for the remaining twelve clusters was ambiguous. Two of the four epidemiological pairs that received molecular support had diverged (by 3 and 15 mutations). These results show that levels of divergence cannot be used simply as an indicator of the likelihood that groups of sequences constitute transmission pairs. Instead, to confirm or refute transmission pairs, it is necessary to assess the likelihood of a common origin of HBV variants in epidemiologically defined transmission groups relative to the HBV diversity in the local community. http://repub.eur.nl/res/pub/36523/ 2007-02-01T00:00:00Z PURPOSE OF REVIEW: To describe recent developments in the community-based approach of high-risk groups for Chlamydia trachomatis infection, and to discuss the assessment of impact of selective systematic screening on the transmission of C. trachomatis in the community. RECENT FINDINGS: Two large home-based screening programs in Europe have recently shown that systematic postal screening for C. trachomatis infection is feasible, but certain high-risk groups are poor participators. This underscores the need for risk selection and targeted approaches. A prediction rule has been developed which can assist in identifying high-risk groups and can be used as a tool for (self) selection for screening. The Internet has been shown to be a promising medium to promote chlamydia testing. School-based programs also succeed in including high-risk groups in screening programs. Recently developed dynamic simulation models, which take into account transmission of C. trachomatis, can assist in the development and evaluation of targeted screening strategies. SUMMARY: Chlamydia will not likely be controlled by one standard approach. Risk selection strategies need further development and different systematic approaches at the community level, including postal screening, school-based screening, and the Internet may produce the desired public health effect of decreasing morbidity and reducing the transmission of C. trachomatis in the community. http://repub.eur.nl/res/pub/7245/ 2006-01-19T00:00:00Z Chlamydia trachomatis (Ct) infections are sexually transmitted, often asymptomatic, and may lead to reduced fertility in women. Available sensitive detection methods on urine and effective single-dose treatment have made home-based screening for Ct infections feasible. In Swedish surveillance data we interpretated increasing chlamydia trends while using more sensitive tests. In a home based screening study in the Netherlands, 15-29 year old men and women were invited by Municipal Health Services. Response was 41%, and Ct prevalence was 0.6% in rural areas and 3.2% in very highly urbanised areas. Nationwide systematic screening is not indicated in the Netherlands and targeted approaches are a better option. We developed a prediction rule based on risk factors which is a promising tool for selective Ct-screening at population level. A reasonable discriminative ability of the rule was shown in population based data from Amsterdam and an outreach screening project among high-risk youth. Conditions for successful management of cases and their partners was studied. The screening method was well accepted and participants with an elevated risk were interested in future screening provided that test kits are easily available. We evaluated whether offering urine test kits in combination with STI prevention activities by the Public Health Service can increase test rates, in high risk and hard to reach migrant populations. Test rate differed by venue , with no difference in test rate in group (80%) and school (73%) settings by sex or ethnicity. 14.5% were Ct positive. School screening may have impact on community prevalence of Ct infections.