Mireille E G Wolfers

Erasmus Universiteit Rotterdam, Rotterdam, South Holland, Netherlands

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Publications (11)25.06 Total impact

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    ABSTRACT: Repeated infections of Chlamydia trachomatis may be new infections or persistent infections due to treatment failure or due to unresolved infections in sexual partners. We aimed to establish the value of using high-resolution multilocus sequence typing (CT-MLST) to discriminate repeated C trachomatis infections. Paired C trachomatis positive samples (baseline (T0) and after 6 months (T1)) were selected from two Dutch screening implementation studies among young heterosexual people. Typing with six CT-MLST loci included the ompA gene. The uniqueness of strains was assessed using 256 reference CT-MLST profiles. In 27 out of 34 paired cases, full sequence types were obtained. A multilocus (13 cases) or single locus variant (4 cases) was seen, indicating 17 new C trachomatis infections at T1. The ompA genovar was identical for 5 of 17 discordant cases. The 10 cases with concordant typing results were categorised as treatment failure (5 cases) versus persistent or recurrent infections (5 cases). Surprisingly, these concordant cases had C trachomatis strains that were either unique or found in small clusters. The median time between T0 and T1 did not differ between the concordant and discordant cases. High-resolution typing was superior in discriminating new infections compared with only using ompA genovar typing. Many cases (37%) showed exactly the same C trachomatis strain after 6 months. CT-MLST is not conclusive in distinguishing recurrent infections from treatment failure.
    Sexually transmitted infections 11/2013; DOI:10.1136/sextrans-2013-051218 · 3.08 Impact Factor
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    ABSTRACT: BACKGROUND: Reinfections of Chlamydia trachomatis (Ct) are common. In a two-armed intervention study at an urban STI clinic in the Netherlands, heterosexual Ct-positive visitors received an invitation for retesting after 4--5 months. Interventions were either home-based sampling by mailed test-kit, or clinic-based testing without appointment. METHODS: Data collection included socio-demographic and sexual behavioural variables at first (T0) and repeat test (T1). Participation in retesting, prevalence and determinants of repeat infection among study participants are described and compared with findings from non-participants. RESULTS: Of the 216 visitors enrolled in the study, 75 accepted retesting (35%). The retest participation was 46% (50/109) in the home group versus 23% (25/107) in the clinic group (p = 0.001). Men were less often retested than women (15% versus 43%, p < 0.001). The overall chlamydia positivity rate at retest was 17.3% (13/75) compared to 12.4% seen at all visits at the STI clinic in 2011. Repeated infections were more frequent among non-Dutch than Dutch participants (27.0% versus 7.9%; p = 0.04) and in persons reporting symptoms (31.0% versus 7.0%; p = 0.01). Both untreated infections of current partners as well as unprotected sex with new partners contribute to repeated infections. CONCLUSION: The high rate of repeated infections indicates the need for interventions to increase retesting; improvement of partner-management and risk reduction counselling remain necessary. Home- based testing was more effective than clinic-based testing. However other strategies, including self-triage of patients, may also increase repeat testing rates and personal preferences should be taken into account.
    BMC Infectious Diseases 05/2013; 13(1):239. DOI:10.1186/1471-2334-13-239 · 2.56 Impact Factor
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    ABSTRACT: Adolescents are a risk group for acquiring sexually transmitted infections (STIs). In the Netherlands, senior vocational school students are particular at risk. However, STI test rates among adolescents are low and interventions that promote testing are scarce. To enhance voluntary STI testing, an intervention was designed and evaluated in senior vocational schools. The intervention combined classroom health education with sexual health services at the school site. The purpose of this study was to assess the combined and single effects on STI testing of health education and school-based sexual health services. In a cluster-randomized study the intervention was evaluated in 24 schools, using three experimental conditions: 1) health education, 2) sexual health services; 3) both components; and a control group. STI testing was assessed by self reported behavior and registrations at regional sexual health services. Follow-up measurements were performed at 1, 3, and 6-9 months. Of 1302 students present at baseline, 739 (57%) completed at least 1 follow-up measurement, of these students 472 (64%) were sexually experienced, and considered to be susceptible for the intervention. Multi-level analyses were conducted. To perform analyses according to the principle of intention-to-treat, missing observations at follow-up on the outcome measure were imputed with multiple imputation techniques. Results were compared with the complete cases analysis. Sexually experienced students that received the combined intervention of health education and sexual health services reported more STI testing (29%) than students in the control group (4%) (OR = 4.3, p < 0.05). Test rates in the group that received education or sexual health services only were 5.7% and 19.9%, not reaching statistical significance in multilevel analyses. Female students were more often tested then male students: 21.5% versus 5.4%. The STI-prevalence in the study group was low with 1.4%. Despite a low dose of intervention that was received by the students and a high attrition, we were able to show an intervention effect among sexually experienced students on STI testing. This study confirmed our hypothesis that offering health education to vocational students in combination with sexual health services at school sites is more effective in enhancing STI testing than offering services or education only.
    BMC Public Health 12/2011; 11:937. DOI:10.1186/1471-2458-11-937 · 2.32 Impact Factor
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    Mireille Wolfers, Onno de Zwart, Gerjo Kok
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    ABSTRACT: Worldwide, adolescents are at risk for sexually transmitted infections (STI). In The Netherlands, test rates among young heterosexual people are low and knowledge on the behavioral determinants of testing is scarce. In this study, we investigated STI testing in more detail with two independent samples of 16-25 year old vocational school students (n = 756/n = 1302). The aim of this study was to examine risk perceptions in relation to STI testing among lower educated adolescents in order to inform the development of an intervention promoting STI testing. We compared multiple measures of risk perception, fear of testing, self-efficacy for testing, and risk knowledge between groups of adolescents engaging and not engaging in risk behavior. The results show that at least half of the participating students with sexual experience underestimated their susceptibility for STI and showed an optimistic bias. Students with sexual experience also considered STI very severe but lacked self-efficacy for testing. This combination can yield a defensive reaction to the threat of STI that, in turn, results in the underestimation of personal risks. However, self-efficacy did not mediate the relationship between intention to test and perceived relative risk. In conclusion, our findings show underestimation of personal risks by vocational school students, a high perceived severity of STI and low self-efficacy for testing. A low level of knowledge regarding sexual risks and symptoms of STI might have contributed to low risk perceptions. Self-efficacy did not change the relation of intention-to-test to perceived risk.
    AIDS patient care and STDs 05/2011; 25(5):311-9. DOI:10.1089/apc.2010.0186 · 3.58 Impact Factor
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    Mireille Wolfers, Onno de Zwart, Gerjo Kok
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    ABSTRACT: This article describes the development of ROsafe, an intervention to promote sexually transmitted infection (STI) testing at vocational schools in the Netherlands. Using the planning model of intervention mapping (IM), an educational intervention was designed that consisted of two lessons, an Internet site, and sexual health services at the school sites. IM is a stepwise approach for theory- and evidence-based development and implementation of interventions. It includes six steps: needs assessment, specification of the objectives in matrices, selection of theoretical methods and practical strategies, program design, implementation planning, and evaluation. The processes and outcomes that are performed during Steps 1 to 4 of IM are presented, that is, literature review and qualitative and quantitative research in needs assessment, leading to the definition of the desired behavioral outcomes and objectives. The matrix of change objectives for STI-testing behavior is presented, and then the development of theory into program is described, using examples from the program. Finally, the planning for implementation and evaluation is discussed. The educational intervention used methods that were derived from the social cognitive theory, the elaboration likelihood model, the persuasive communication matrix, and theories about risk communication. Strategies included short movies, discussion, knowledge quiz, and an interactive behavioral self-test through the Internet.
    Health Promotion Practice 03/2011; 13(3):378-87. DOI:10.1177/1524839910384343 · 0.55 Impact Factor
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    Mireille E G Wolfers, Gerjo Kok, Johan P Mackenbach, Onno de Zwart
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    ABSTRACT: Adolescents are at risk for acquiring sexually transmitted infections (STIs). However, test rates among adolescents in the Netherlands are low and effective interventions that encourage STI testing are scarce. Adolescents who attend vocational schools are particularly at risk for STI. The purpose of this study is to inform the development of motivational health promotion messages by identifying the psychosocial correlates of STI testing intention among adolescents with sexual experience attending vocational schools. This study was conducted among 501 students attending vocational schools aged 16 to 25 years (mean 18.3 years ± 2.1). Data were collected via a web-based survey exploring relationships, sexual behavior and STI testing behavior. Items measuring the psychosocial correlates of testing were derived from Fishbein's Integrative Model. Data were subjected to multiple regression analyses. Students reported substantial sexual risk behavior and low intention to participate in STI testing. The model explained 39% of intention to engage in STI testing. The most important predictor was attitude. Perceived norms, perceived susceptibility and test site characteristics were also significant predictors. The present study provides important and relevant empirical input for the development of health promotion interventions aimed at motivating adolescents at vocational schools in the Netherlands to participate in STI testing. Health promotion interventions developed for this group should aim to change attitudes, address social norms and increase personal risk perception for STI while also promoting the accessibility of testing facilities.
    BMC Public Health 11/2010; 10:725. DOI:10.1186/1471-2458-10-725 · 2.32 Impact Factor
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    ABSTRACT: There is currently a trend towards unsafe unprotected anal intercourse (UAI) among men who have sex with men. We evaluated a short individual counselling session on reducing UAI among gay and bisexual men. A quasi-experimental design was used to evaluate the counselling session. This session was conducted during consulting hours at four municipal health clinics during a Hepatitis B vaccination campaign. These clinics offered free vaccination to high-risk groups, such as gay and bisexual men.All gay and bisexual men attending health clinics in four cities in the Netherlands were asked to participate. Each participant in the intervention group received a fifteen-minute individual counselling based on the Theory of Planned Behaviour and Motivational Interviewing. Changes in UAI were measured over a 5-months period, using self-administered questionnaires. UAI was measured separately for receptive and insertive intercourse in steady and casual partners. These measures were combined in an index-score (range 0-8). While UAI in the counselling group remained stable, it increased in the controls by 66% from 0.41 to 0.68. The results show that the intervention had a protective effect on sexual behaviour with steady partners. Intervention effects were strongest within steady relationships, especially for men whose steady-relationship status changed during the study. The intervention was well accepted among the target group. The fifteen-minute individually tailored counselling session was not only well accepted but also had a protective effect on risk behaviour after a follow-up of six months.
    BMC Public Health 08/2009; 9:255. DOI:10.1186/1471-2458-9-255 · 2.32 Impact Factor
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    ABSTRACT: Safe sex negotiation and communication about sexual risks with partners is important for women to ensure sexual risk reduction. This paper describes the results of a survey on safer sex and negotiation behavior, and the correlates of negotiation with partners among 128 women from Surinamese and Dutch Antillean descent in the Netherlands. The key findings are that 50% of the participants had negotiated sexual risk reduction with their partner, yet only 40% of the women who negotiated safer sex actually claimed practicing safe sex. Participants defined safe sex with steady partners primarily as negotiated safety and monogamy, and safe sex with casual partners primarily as condom use. Intentions to negotiate safer sex with steady partners were related to positive attitudes and perceived injunctive norms towards safe sex negotiation, and educational background. Intention to discuss safe sex with casual partners were primarily related to attitudes and perceived self-efficacy. STI/HIV prevention interventions targeting these women should incorporate awareness-raising of safety in different types of relationships, deciding on the appropriateness of relation-specific sexual risk reduction strategies, and building negotiation skills to accomplish the realization of these strategies.
    AIDS Care 12/2008; 20(10):1211-6. DOI:10.1080/09540120802009070 · 1.60 Impact Factor
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    ABSTRACT: Young adults attending vocational schools in the Netherlands are regarded as a high-risk group for Sexually Transmitted Diseases. Within the academic partnership of Rotterdam-Rijnmond, in which the Municipal Health Service and Erasmus University Medical Center are collaborating, a project has start for the prevention of STI in vocational students. Using the Intervention Mapping protocol we developed an educational programme which has been carried out at the schools, accompanied by STI-consulting hours at the school sites. The aim of the intervention is to promote safe sex and STI-testing. The effect of the intervention is studied using an experimental design. We describe the development of the research question and the intervention, also elaborating on the collaboration between the academic department, the health service and vocational schools. Key words: STI prevention, Students, Health education, Academic partnership
    06/2008; 86(6):278-280. DOI:10.1007/BF03082098
  • Liver international: official journal of the International Association for the Study of the Liver 07/2007; 27(5):731-2. DOI:10.1111/j.1478-3231.2007.01479.x · 4.41 Impact Factor
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    ABSTRACT: There is little experience with carefully developed interventions in the HIV/STI prevention field aimed at adult heterosexual target groups in the Netherlands. The ability to apply intervention development protocols, like Intervention Mapping, in daily practice outside of academia, is a matter of concern. An urgent need also exists for interventions aimed at the prevention of STI in migrant populations in the Netherlands. This article describes the theory and evidence based development of HIV/STI prevention interventions by the Municipal Public Health Service Rotterdam Area (MPHS), the Netherlands, for heterosexual migrant men with Surinamese, Dutch-Caribbean, Cape Verdean, Turkish and Moroccan backgrounds. First a needs assessment was carried out. Then, a literature review was done, key figures were interviewed and seven group discussions were held. Subsequently, the results were translated into specific objectives ("change objectives") and used in intervention development for two subgroups: men with an Afro-Caribbean background and unmarried men with a Turkish and Moroccan background. A matrix of change objectives was made for each subgroup and suitable theoretical methods and practical strategies were selected. Culturally-tailored interventions were designed and were pre-tested among the target groups. This development process resulted in two interventions for specific subgroups that were appreciated by both the target groups and the migrant prevention workers. The project took place in collaboration with a university center, which provided an opportunity to get expert advice at every step of the Intervention Mapping process. At relevant points of the development process, migrant health educators and target group members provided advice and feedback on the draft intervention materials. This intervention development project indicates that careful well-informed intervention development using Intervention Mapping is feasible in the daily practice of the MPHS, provided that sufficient time and expertise on this approach is available. Further research should test the effectiveness of these interventions.
    BMC Public Health 02/2007; 7:141. DOI:10.1186/1471-2458-7-141 · 2.32 Impact Factor

Publication Stats

45 Citations
25.06 Total Impact Points

Institutions

  • 2007–2011
    • Erasmus Universiteit Rotterdam
      • Department of Public Health (MGZ)
      Rotterdam, South Holland, Netherlands
  • 2010
    • Gemeentelijke Geneeskundige en Gezondheidsdienst
      Utrecht, Utrecht, Netherlands
  • 2007–2008
    • Municipal Health Service of South Netherlands
      Dordt, South Holland, Netherlands