• Risk factors for gastroenteritis associated with canal swimming in two cities in the Netherlands during the summer of 2015: A prospective study.

      Joosten, Rosa; Sonder, Gerard; Parkkali, Saara; Brandwagt, Diederik; Fanoy, Ewout; Mughini-Gras, Lapo; Lodder, Willemijn; Ruland, Erik; Siedenburg, Evelien; Kliffen, Suzanne; van Pelt, Wilfrid (2017)
      Urban canal swimming events are popular in the Netherlands. In 2015, two city canal swimming events took place, in Utrecht (Utrecht Singel Swim, USS) and in Amsterdam (Amsterdam City Swim, ACS). This prospective study characterizes the health risks associated with swimming in urban waters. Online questionnaires were sent to 160 (USS) and 2,692 (ACS) participants, with relatives of participants who did not swim completing the questionnaire as a control. Swimming water specimens and stool specimens of diarrheic participants in the ACS group were analysed. A total of 49% of USS and 51% of ACS swimmers returned their questionnaires. Nine percent of USS swimmers and 4% of non-swimmers reported gastrointestinal complaints (aRR 2.1; 95% CI: 0.3-16), while a total of 31% of ACS swimmers and 5% of non-swimmers reported gastrointestinal complaints (aRR 6.3; 95% CI: 4.1-9.5). AGI risk among ACS participants was directly related to increasing number of mouthfuls of water swallowed. Various norovirus genotypes were detected in five out of seven stool specimens taken from ACS participants and in all three tested ACS water samples. We conclude that the AGI risk among open-water swimmers in urban areas depends on the circumstances around the event. The epidemiological curve, the statistical association between swimming and AGI, and the microbiological evidence for norovirus in stool and water specimens suggest that AGI outbreak after the ACS event was due to water contamination by multiple norovirus strains, which is possibly linked to sewage overflow due to prior heavy rainfall. There is need for more targeted preventive measurements and recommendations for organizers, municipal authorities and participants to prevent this reoccurring in the future.
    • Screening for HIV, hepatitis B and syphilis on dried blood spots: A promising method to better reach hidden high-risk populations with self-collected sampling.

      van Loo, Inge H M; Dukers-Muijrers, Nicole H T M; Heuts, Rosalie; van der Sande, Marianne A B; Hoebe, Christian J P A (2017)
      Many people at high risk for sexually transmitted infections (STIs), e.g., men who have sex with men (MSM), are not optimally reached by current sexual health care systems with testing. To facilitate testing by home-based sampling or sampling in outreach setting we evaluated dried blood spots (DBS), a method for self-collected blood sampling for serological screening of HIV, hepatitis B (HBV) and syphilis. The aims of this study were to assess the acceptability and feasibility of self-collected DBS and to compare the test results for screening of HIV, HBV and syphilis from DBS with blood drawn by venous puncture.
    • Temporal associations between national outbreaks of meningococcal serogroup W and C disease in the Netherlands and England: an observational cohort study.

      Knol, Mirjam J; Hahné, Susan J M; Lucidarme, Jay; Campbell, Helen; de Melker, Hester E; Gray, Stephen J; Borrow, Ray; Ladhani, Shamez N; Ramsay, Mary E; van der Ende, Arie (2017-10)
      Since 2009, the incidence of meningococcal serogroup W disease has increased rapidly in the UK because of a single strain (the so-called original UK strain) belonging to the hypervirulent sequence type-11 clonal complex (cc11), with a variant outbreak strain (the so-called 2013 strain) emerging in 2013. Subsequently, the Netherlands has had an increase in the incidence of meningococcal serogroup W disease. We assessed the temporal and phylogenetic associations between the serogroup W outbreaks in the Netherlands and England, and the historical serogroup C outbreaks in both countries.
    • Varicella vaccination elicits a humoral and cellular response in children with rheumatic diseases using immune suppressive treatment.

      Groot, Noortje; Pileggi, Gecilmara; Sandoval, Cleonice B; Grein, Ingrid; Berbers, Guy; Ferriani, Virginia Paes Leme; Wulffraat, Nico; de Roock, Sytze (2017-05-15)
      To assess humoral and cellular responses to live-attenuated varicella zoster virus (VZV) vaccination of patients with juvenile idiopathic arthritis (JIA), juvenile dermatomyositis (JDM) or juvenile scleroderma (JScle) compared to those of healthy controls (HC).