M J W van de Laar
European Centre for Disease Prevention and Control
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Featured researches published by M J W van de Laar.
Sexually Transmitted Infections | 1996
M J W van de Laar; Y. T. H. P. Van Duynhoven; J. S. A. Fennema; J. M. Ossewaarde; A. J. C. Van Den Brule; G. J. J. Van Doornum; R. A. Coutinho; J. A. R. Van Den Hoek
OBJECTIVES: To study the association of serovars of Chlamydia trachomatis with clinical manifestations of genital tract infection and socio-demographic characteristics. METHODS: In 1986-88 the C trachomatis isolates from 159 heterosexual men and 116 women attending a sexually transmitted disease (STD) clinic were collected and typed accordingly. A medical history was recorded, a physical examination took place and samples were taken for laboratory diagnostics. RESULTS: Serovars E, F and D were the most common for both men (75%) and women (67%). Men infected with serovars of the C-complex had more often a history of STD (p = 0.06). The opposite was demonstrated in women (p = 0.07). In addition, women younger than 18 years at first intercourse were more often infected with C-complex serovars (p = 0.05). For men, the serovars F/G less often produced symptoms of urethral discharge (p = 0.01) than the serovars of the B-complex and C-complex and were less often associated with the presence of 10 or more leukocytes in a Gram-stained smear (p = 0.04). CONCLUSIONS: In this study, infections with serovars F and G caused less obvious symptoms and signs of inflammation in men; in women no differences were found in the clinical manifestation of infections with different serovars.
Sexually Transmitted Infections | 2008
Merlijn A. Kramer; M van Veen; E L M Op de Coul; Ronald B. Geskus; R. A. Coutinho; M J W van de Laar; Maria Prins
Background: By having unprotected heterosexual contact in both The Netherlands and their homeland, migrants who travel to their homeland might form a bridge population for HIV and sexually transmitted infection (STI) transmission. We studied the determinants for such a population in two large migrant communities in The Netherlands. Methods: From 2003 to 2005, 1938 people of Surinamese and Antillean origin were recruited at social venues in two large cities, interviewed and their saliva samples tested for HIV antibodies. We used multivariate multinomial logistic regression to explore characteristics of groups with four risk levels (no, low, moderate and high) for cross-border transmission. Results: 1159/1938 (60%) participants had travelled from The Netherlands to their homeland in the previous 5 years and 1092 (94%) of them reported partnerships and condom use in both countries. Of these 9.2% reported having unprotected sex with partners in both countries. People in this high-risk or bridge population group were more likely to be male, frequent travellers and older compared with people who had no sex or had sexual contact solely in one country in the past 5 years. Conclusions: Older male travellers of Surinamese and Antillean origin are at high risk for cross-border heterosexual transmission of HIV/STIs. They should be targeted by prevention programmes, which are focused on sexual health education and HIV/STI testing, to raise their risk awareness and prevent transmission.
Sexually Transmitted Infections | 1997
M J W van de Laar; Y. T. H. P. Van Duynhoven; M. Dessens; M van Santen; B. Van Klingeren
OBJECTIVE: To evaluate the prevalence and epidemiology of penicillinase producing Neisseria gonorrhoeae (PPNG) and tetracycline resistant N gonorrhoeae (TRNG) in the period 1977-95 in the Netherlands. To compare auxotypes, serovars, and antibiograms of PPNG, non-PPNG, and TRNG. To identify determinants in patient characteristics for the epidemic spread of TRNG/PPNG. METHODS: With respect to the national gonococcal surveillance all PPNG isolates from 30 laboratories over the country in 1977-90 and all gonococcal isolates from five sentinel laboratories (during 1 month per quarter) in 1991-5 were collected. Isolates were auxotyped and serotyped, the susceptibility for various antibiotics was tested and plasmid contents were evaluated. Additional data on PPNG infected individuals were collected retrospectively during a microepidemic of TRNG/PPNG. Univariate and multivariate analyses were performed to identify risk factors for TRNG/PPNG infections. RESULTS: In 1995 an overall high prevalence of PPNG infection (27%) and TRNG among PPNG infection (24%) was found in the Netherlands. Importantly, PPNG were found to have higher MICs for ceftriaxone and ciprofloxacin than non-PPNG; clinically relevant resistance to these antibiotics (or related agents) may emerge first among these strains. The observed diversity of strains (123 auxo/serovar classes since 1988) indicates a continuous introduction of new strains into the community. The epidemic increase of TRNG/PPNG was mainly caused by A/S classes NR/1B-6, PRO/1A-3, and PRO/1A-6, suggesting a clonal spread of a few strains; the rapid spread was associated with transmission in high risk individuals (that is, prostitutes and their clients). CONCLUSION: The prevalence of PPNG in the Netherlands remains high and reduced sensitivity to other antimicrobials was detected among the PPNG strains. This underlines the necessity for a continuous national surveillance of resistance in gonococci including limited epidemiological information.
Eurosurveillance | 2014
Michelle Cole; Gianfranco Spiteri; S A Chisholm; Steen Hoffmann; Catherine A Ison; Magnus Unemo; M J W van de Laar
Neisseria gonorrhoeae has consistently developed resistance to antimicrobials used therapeutically for gonorrhoea and few antimicrobials remain for effective empiric first-line therapy. Since 2009 the European gonococcal antimicrobial surveillance programme (Euro-GASP) has been running as a sentinel surveillance system across Member States of the European Union (EU) and European Economic Area (EEA) to monitor antimicrobial susceptibility in N. gonorrhoeae. During 2011, N. gonorrhoeae isolates were collected from 21 participating countries, and 7.6% and 0.5% of the examined gonococcal isolates had in vitro resistance to cefixime and ceftriaxone, respectively. The rate of ciprofloxacin and azithromycin resistance was 48.7% and 5.3%, respectively. Two (0.1%) isolates displayed high-level resistance to azithromycin, i.e. a minimum inhibitory concentration (MIC) ≥256 mg/L. The current report further highlights the public health need to implement the European response plan, including further strengthening of Euro-GASP, to control and manage the threat of multidrug resistant N. gonorrhoeae.
Aids Care-psychological and Socio-medical Aspects of Aids\/hiv | 2009
M van Veen; Merlijn A. Kramer; E L M Op de Coul; A P van Leeuwen; O. de Zwart; M J W van de Laar; R. A. Coutinho; Maria Prins
Abstract To gain insight into the transmission of HIV and sexually transmitted infection (STI) among large migrant groups in the Netherlands, we studied the associations between their demographic and sexual characteristics, in particular condom use, and their sexual mixing patterns with other ethnic groups. In 2002–2005, cross-sectional surveys were conducted among migrants from Surinam (Afro- and Hindo-), the Netherlands Antilles, Cape Verde, and Ghana at social venues in three large cities. A questionnaire was administrated and a saliva sample was collected for HIV antibody testing. Of 2105 migrants recruited, 1680 reported sexual contacts, of whom 41% mixed sexually with other ethnicities, including the indigenous Dutch population. Such disassortative mixing was associated with being second-generation migrant, having several sexual partners, and having a steady and concurrent casual partner. Less disassortative mixing occurred in participants reporting visiting the country of origin. The association between condom use and sexual mixing differed by gender, with men using condoms inconsistently being most likely to be mixing with the Dutch indigenous population. HIV infection and recent STI treatment were not associated with disassortative mixing. This study shows substantial sexual mixing among migrant groups. Since disassortative mixing is more prevalent in second-generation migrants, it might increase in the upcoming years. The mixing patterns in relation to concurrency and the reported condom use in this study suggest a possibly increased level of HIV/STI transmission not only within migrant groups but also between migrant groups, especially via men who mix with the indigenous population and via migrant women who mix with non-Dutch casual partners. Although the observed HIV prevalence in migrants (0.6%) is probably too low to lead to much HIV transmission between ethnicity groups, targeted prevention measures are needed to prevent transmission of other STI.
Eurosurveillance | 2013
J Janiec; K Haar; Gianfranco Spiteri; G Likatavicius; M J W van de Laar; Andrew Amato-Gauci
In 2012, newly reported human immunodeficiency virus diagnoses in the European Union /European Economic Area remained stable at around 30,000 cases. Since 2003, cases in men who have sex with men (MSM) aged 20 to 29 years-old doubled, while the proportion of late presenters in this group remained stable. Persistent declines occurred among older MSM age groups, particularly that between 30 and 39 years-old. Interventions targeting younger MSM are needed to prevent a resurgence of the epidemic in Europe.
Sexually Transmitted Infections | 1995
Y. T. H. P. Van Duynhoven; M J W van de Laar; J. S. A. Fennema; G. J. J. Van Doornum; J. A. R. Van Den Hoek
OBJECTIVES--To identify predictors for Chlamydia trachomatis infection among visitors of an STD clinic in Amsterdam in 1986-1988. To design predictor-based screening programmes for C trachomatis. To evaluate the chosen screening strategy in 1993. METHODS--In 1986-1988, 947 heterosexual men and 648 women participated in the study. A medical history was recorded, a physical examination took place and samples were taken for laboratory diagnostics. Information for 1993 was available from routine databases. RESULTS--C trachomatis infections in heterosexual men in 1986-1988 (prevalence 15.8%) were independently associated with: age under 26 years, being an STD contact, coitarche below 13, last sexual contact with a non-prostitute, (muco)-purulent urethral discharge and ten or more leukocytes per microscopic field of urethral smear or urine. For women (prevalence 21.5%) independent predictors were age under 26, no history of STD, being an STD contact, cervical friability, (muco)purulent cervical discharge, presence of clue cells and ten or more leukocytes per field of urethral smear. Screening men with one anamnestic predictor for C trachomatis and ten or more leukocytes in smear or urine (59% of men) would detect 93% of the cases in 1986-1988. For females only universal screening proved to be suitable. After the introduction of a screening strategy in 1989 (universal for women, indicated by urethritis for men), a strong decline was found in the C trachomatis prevalence for all subgroups in 1993, excluding prostitutes clients and Turkish men. CONCLUSIONS--In 1993 the overall C trachomatis prevalence had declined among the attendants of the STD clinic. It seems likely that this fall was caused both by the screening programme and the reduction of risk behaviour.
Sexually Transmitted Infections | 1997
Y. T. H. P. Van Duynhoven; M J W van de Laar; W. A. Schop; P. H. Rothbarth; W. I. Van Der Meijden; A. M. Van Loon; M. J. W. Sprenger
OBJECTIVE: To determine the prevalence and risk factors for hepatitis B virus (HBV) infections among individuals attending an STD clinic in a low endemic region. STUDY DESIGN: A total of 1228 women and 1648 men attending the STD clinic at the University Hospital Rotterdam, Netherlands, were examined for HBV infection by determination of hepatitis B surface antigen (HBsAg) and antibodies to hepatitis B core antigen (anti-HBc). Demographic characteristics, information on sexual behaviour, and intravenous drug use were recorded. RESULTS: The seroprevalence of HBsAg was 1.4% in women and 2.1% in men (0% in homosexual men). The seroprevalence of anti-HBc was 13% in women and 20% in men (36% in homosexual men). Native country, intravenous drug use, a history of STD, and the number of partners in the past half year (inversely) were independent risk factors for HBsAg positivity in women and heterosexual men. For anti-HBc independent associations were observed for native country, age, intravenous drug use, commercial sex, number of lifetime partners, homosexual contacts, orogenital contact (inverse), and a history of STD. CONCLUSION: The HBV prevalence in the STD clinic attendants was high, exceeding the national estimate, and indicates that the STD clinic population may be considered a high risk group. Our data confirmed an increased risk for HBV infections among established risk groups. Therefore, these risk groups should be routinely screened to identify HBV cases for counselling and contact tracing.
Eurosurveillance | 2013
Dagmar Hedrich; E Kalamara; O Sfetcu; Anastasia Pharris; André Noor; Lucas Wiessing; Vivian Hope; M J W van de Laar
In most European Union (EU)/European Economic Area (EEA) countries, between 2010 and 2012, reports of new human immunodeficiency virus (HIV) diagnoses among people who inject drugs have been stable or declining. HIV outbreaks in Greece and Romania, first reported in 2011, continue and economic conditions hinder provision of effective response coverage. When measured against some established thresholds, prevention coverage remains inadequate in at least one-third of EU/EEA countries. Urgent consideration to scale up prevention efforts is merited.
Journal of Viral Hepatitis | 2015
Erika Duffell; M J W van de Laar; Andrew Amato-Gauci
Robust epidemiological information on hepatitis B is important to help countries plan prevention and control programmes and evaluate public health responses to control transmission. European Centre Disease Prevention and Control (ECDC) introduced enhanced surveillance of hepatitis B at EU/EEA level in 2011 to collate routine surveillance data from national notification systems. Analysis of the data collected for the years 2006–2012 shows a high burden of hepatitis B across Europe with 110 005 cases reported over the period with the majority of these cases being chronic infections. The most commonly reported routes of transmission in acute cases included heterosexual transmission, nosocomial transmission, injecting drug use and transmission among men who have sex with men. Mother‐to‐child transmission was the most common route reported for chronic cases. Trends over time were difficult to analyse as national reporting practices changed, but data suggest a downward trend in acute cases, which probably reflects the impact of the widespread implementation of vaccination programmes. Notifications of chronic infection varied across countries and showed discrepancy with the expected results based on findings from recent prevalence surveys. This indicated that notifications mirror local testing practices rather than real occurrence of disease. Improving the quality of the data and considering reported notifications alongside other data sources, such as local screening practices and vaccination policies, will improve the utility of the data.