• Induction of salivary antibody levels in Dutch adolescents after immunization with monovalent meningococcal serogroup C or quadrivalent meningococcal serogroup A, C, W and Y conjugate vaccine.

      van Ravenhorst, Mariëtte B; den Hartog, Gerco; van der Klis, Fiona R M; van Rooijen, Debbie M; Sanders, Elisabeth A M; Berbers, Guy A M (2018)
      Meningococcal infection starts with colonisation of the upper respiratory tract. Mucosal immunity is important for protection against acquisition and subsequent meningococcal carriage. In this study, we assessed salivary antibody levels against meningococcal serogroup A (MenA), W (MenW) and Y (MenY) after vaccination with a quadrivalent MenACWY conjugated vaccine. We also compared salivary meningococcal serogroup C (MenC) antibody levels after monovalent MenC and quadrivalent MenACWY conjugated vaccination.
    • Inductively coupled plasma-mass spectrometry in biodistribution studies of (engineered) nanoparticles

      Krystek, P; Cirtiu, CM; Braakhuis, H; Park, M; de Jong, W (2919-04-18)
    • Infecties met Leptospira en Francisella tularensis gerelateerd aan buitensportevenementen.

      Pijnacker, R; Koene, M; Goris, M; te Wierik, M; Janse, I; Tulen, A; Kortbeek, T; Voordouw, B; Franz, E (2019-03-11)
    • Infectieziektensyndroomsurveillance bij asielzoekers.

      Mollers M; Hooiveld M; Evers S; Goosen S; Verheij R; Broek I van den (2016-11)
    • Infection prevalence and ecotypes of Anaplasma phagocytophilum in moose Alces alces, red deer Cervus elaphus, roe deer Capreolus capreolus and Ixodes ricinus ticks from Norway.

      Stigum, Vetle M; Jaarsma, Ryanne I; Sprong, Hein; Rolandsen, Christer M; Mysterud, Atle (2019-01-03)
      The geographical expansion of the tick Ixodes ricinus in northern Europe is a serious concern for animal and human health. The pathogen Anaplasma phagocytophilum is transmitted by ticks and causes emergences of tick-borne fever (anaplasmosis) in livestock. The transmission dynamics of the different ecotypes of A. phagocytophilum in the ecosystems is only partly determined. Red deer and roe deer contribute to circulation of different ecotypes of A. phagocytophilum in continental Europe, while the role of moose for circulation of different ecotypes is not fully established but an important issue in northern Europe. We determined infection prevalence and ecotypes of A. phagocytophilum in moose (n = 111), red deer (n = 141), roe deer (n = 28) and questing ticks (n = 9241) in Norway. As previously described, red deer was exclusively linked to circulation of ecotype I, while roe deer was exclusively linked to circulation of ecotype II. Surprisingly, we found 58% ecotype I (n = 19) and 42% of ecotype II (n = 14) in moose. Both ecotypes were found in questing ticks in areas with multiple cervid species present, while only ecotype I was found in ticks in a region with only red deer present. Hence, the geographical distribution of ecotypes in ticks followed the distribution of cervid species present in a given region and their link to ecotype I and II. Moose probably function as reservoirs for both ecotype I and II, indicating that the ecotypes of A. phagocytophilum are not entirely host-specific and have overlapping niches. The disease hazard depends also on both host abundance and the number of immature ticks fed by each host. Our study provides novel insights in the northern distribution and expansion of tick-borne fever.
    • Infection risks of city canal swimming events in the Netherlands in 2016.

      Hintaran, A D; Kliffen, S J; Lodder, W; Pijnacker, R; Brandwagt, D; van der Bij, A K; Siedenburg, E; Sonder, G J B; Fanoy, E B; Joosten, R E (2018)
      Swimming events in city canals are gaining popularity in the Netherlands, even though canal water is usually not officially designated for recreational use. Knowledge regarding the risk of infection after swimming in canals is limited. An outbreak was reported in 2015 following a canal swimming event in Utrecht, the Netherlands. Local governments were concerned about the health risks of such events. In order to assess the safety of canal swimming, the Public Health Service (PHS) prospectively investigated two city canal swimming events in 2015. In 2016, we repeated this study, aiming to prospectively determine the risks of infection during two urban swimming events, the Utrecht SingelSwim 2016 (USS) and the Amsterdam City Swim 2016 (ACS).
    • Infectious reactivation of cytomegalovirus explaining age- and sex-specific patterns of seroprevalence.

      van Boven, Michiel; van de Kassteele, Jan; Korndewal, Marjolein J; van Dorp, Christiaan H; Kretzschmar, Mirjam; van der Klis, Fiona; de Melker, Hester E; Vossen, Ann C; van Baarle, Debbie (2017-09)
      Human cytomegalovirus (CMV) is a herpes virus with poorly understood transmission dynamics. Person-to-person transmission is thought to occur primarily through transfer of saliva or urine, but no quantitative estimates are available for the contribution of different infection routes. Using data from a large population-based serological study (n = 5,179), we provide quantitative estimates of key epidemiological parameters, including the transmissibility of primary infection, reactivation, and re-infection. Mixture models are fitted to age- and sex-specific antibody response data from the Netherlands, showing that the data can be described by a model with three distributions of antibody measurements, i.e. uninfected, infected, and infected with increased antibody concentration. Estimates of seroprevalence increase gradually with age, such that at 80 years 73% (95%CrI: 64%-78%) of females and 62% (95%CrI: 55%-68%) of males are infected, while 57% (95%CrI: 47%-67%) of females and 37% (95%CrI: 28%-46%) of males have increased antibody concentration. Merging the statistical analyses with transmission models, we find that models with infectious reactivation (i.e. reactivation that can lead to the virus being transmitted to a novel host) fit the data significantly better than models without infectious reactivation. Estimated reactivation rates increase from low values in children to 2%-4% per year in women older than 50 years. The results advance a hypothesis in which transmission from adults after infectious reactivation is a key driver of transmission. We discuss the implications for control strategies aimed at reducing CMV infection in vulnerable groups.
    • Inferring Pathogen Type Interactions Using Cross-sectional Prevalence Data: Opportunities and Pitfalls for Predicting Type Replacement.

      Man, Irene; Wallinga, Jacco; Bogaards, Johannes A (2018-09)
      Many multivalent vaccines target only a subset of all pathogenic types. If vaccine and nonvaccine types compete, vaccination may lead to type replacement. The plausibility of type replacement has been assessed using the odds ratio (OR) of co-infections in cross-sectional prevalence data, with OR > 1 being interpreted as low risk of type replacement. The usefulness of the OR as a predictor for type replacement is debated, as it lacks a theoretical justification, and there is no framework explaining under which assumptions the OR predicts type replacement.
    • Inflammatory potential of the diet and risk of gastric cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC) study.

      Agudo, Antonio; Cayssials, Valerie; Bonet, Catalina; Tjønneland, Anne; Overvad, Kim; Boutron-Ruault, Marie-Christine; Affret, Aurélie; Fagherazzi, Guy; Katzke, Verena; Schübel, Ruth; et al. (2018-04-01)
      Chronic inflammation plays a critical role in the pathogenesis of the 2 major types of gastric cancer. Several foods, nutrients, and nonnutrient food components seem to be involved in the regulation of chronic inflammation.
    • Influence of adjuvant formulation on inducing immune response in mice immunized with a recombinant serpin from Trichinella spiralis.

      Xu, J; Bai, X; Wang, L B; Shi, H N; van der Giessen, J W B; Boireau, P; Liu, M Y; Liu, X L (2017-07)
      Nematodes of the genus Trichinella are one of the most widespread zoonotic pathogens on the world, and they can still cause major public health problems in many parts of the world. Vaccination against the helminth nematode Trichinella could be a good strategy to reduce the risk of human and animal infection. It was our aim to evaluate three adjuvants, which could be used as an efficient vaccine for animals in combination with rTs-Serpin antigen. In this study, BALB/c mice were vaccinated by an intramuscular route with rTs-Serpin antigen from the parasite Trichinella spiralis in combination with three different adjuvant formulations: Montanide ISA201, Montanide IMS 1313 N PR VG and Freund's complete adjuvant/Freund's incomplete adjuvant (FCA/FIA). The dynamics of IgG, IgM, IgE and cytokine production from spleen cells and worm reduction rate of the vaccinated mice were analysed. The results showed that rTs-serpin can induce partial protection against Trichinella larvae challenge in mice, when compared to the FCA-/FIA-formulated vaccination, the IMS1313 plus rTs-serpin mixture showed higher humoral immunity and similar levels of cellular immunity and worm reduction rate. The study suggested that Montanide IMS nanoparticles 1313 are as effective as FCA but less toxic; thus, Montanide IMS nanoparticles 1313 can be used as a good candidate of adjuvant for developing vaccine against Trichinella spiralis.
    • Influence of demographic changes on the impact of vaccination against varicella and herpes zoster in Germany - a mathematical modelling study.

      Horn, Johannes; Damm, Oliver; Greiner, Wolfgang; Hengel, Hartmut; Kretzschmar, Mirjam E; Siedler, Anette; Ultsch, Bernhard; Weidemann, Felix; Wichmann, Ole; Karch, André; et al. (2018-01-09)
      Epidemiological studies suggest that reduced exposure to varicella might lead to an increased risk for herpes zoster (HZ). Reduction of exposure to varicella is a consequence of varicella vaccination but also of demographic changes. We analyzed how the combination of vaccination programs and demographic dynamics will affect the epidemiology of varicella and HZ in Germany over the next 50 years.
    • The Influence of Meteorological Factors and Atmospheric Pollutants on the Risk of Preterm Birth.

      Giorgis-Allemand, Lise; Pedersen, Marie; Bernard, Claire; Aguilera, Inmaculada; Beelen, Rob M J; Chatzi, Leda; Cirach, Marta; Danileviciute, Asta; Dedele, Audrius; van Eijsden, Manon; et al. (2017-02-15)
      Atmospheric pollutants and meteorological conditions are suspected to be causes of preterm birth. We aimed to characterize their possible association with the risk of preterm birth (defined as birth occurring before 37 completed gestational weeks). We pooled individual data from 13 birth cohorts in 11 European countries (71,493 births from the period 1994-2011, European Study of Cohorts for Air Pollution Effects (ESCAPE)). City-specific meteorological data from routine monitors were averaged over time windows spanning from 1 week to the whole pregnancy. Atmospheric pollution measurements (nitrogen oxides and particulate matter) were combined with data from permanent monitors and land-use data into seasonally adjusted land-use regression models. Preterm birth risks associated with air pollution and meteorological factors were estimated using adjusted discrete-time Cox models. The frequency of preterm birth was 5.0%. Preterm birth risk tended to increase with first-trimester average atmospheric pressure (odds ratio per 5-mbar increase = 1.06, 95% confidence interval: 1.01, 1.11), which could not be distinguished from altitude. There was also some evidence of an increase in preterm birth risk with first-trimester average temperature in the -5°C to 15°C range, with a plateau afterwards (spline coding, P = 0.08). No evidence of adverse association with atmospheric pollutants was observed. Our study lends support for an increase in preterm birth risk with atmospheric pressure.
    • The influence of neonatal Bacille Calmette-Guérin (BCG) immunisation on heterologous vaccine responses in infants.

      Zimmermann, Petra; Donath, Susan; Perrett, Kirsten P; Messina, Nicole L; Ritz, Nicole; Netea, Mihai G; Flanagan, Katie L; van der Klis, Fiona R M; Curtis, Nigel (2019-06-19)
    • Influence of vitamin D on key bacterial taxa in infant microbiota in the KOALA Birth Cohort Study.

      Talsness, Chris E; Penders, John; Jansen, Eugène H J M; Damoiseaux, Jan; Thijs, Carel; Mommers, Monique (2017)
      Vitamin D has immunomodulatory properties giving it the potential to affect microbial colonization of the intestinal tract. We investigated whether maternal vitamin D supplemention, maternal plasma 25-hydroxyvitamin D concentration, or direct supplementation of the infant influences key bacterial taxa within microbiota of one month old infants. Infant and maternal vitamin D supplement use was ascertained via questionnaires. Maternal plasma 25-hydroxyvitamin D was determined at approximately the 36th week of pregnancy. In 913 one month old infants in the prospective KOALA Birth Cohort Study, fecal Bifidobacterium spp., Escherichia coli, Clostridium difficile, Bacteroides fragilis group, Lactobacillus spp. and total bacteria were quantified with real-time polymerase chain reaction assays targeting 16S rRNA gene sequences. The association between vitamin D exposure and prevalence or abundance of a specific bacterial group or species was analyzed using logistic or linear regression, respectively. There was a statistically significant negative linear trend between counts of Bifidobacterium spp. and levels of maternal vitamin D supplementation and maternal 25-hydroxyvitamin D quintiles, respectively. In addition, a positive linear trend between quintile groups and B. fragilis group counts was observed. Lower counts of C. difficile were associated with vitamin D supplementation of breast fed infants whose mothers were more likely to adhere to an alternative lifestyle in terms of, e.g., dietary habits. These data suggest that vitamin D influences the abundance of several key bacterial taxa within the infant microbiota. Given that intestinal microbiotic homeostasis may be an important factor in the prevention of immune mediated diseases and that vitamin D status is a modifiable factor, further investigation of the impact of postnatal vitamin D supplementation should be conducted in older infants.
    • Influenza vaccination in patients with lung cancer receiving anti-programmed death receptor 1 immunotherapy does not induce immune-related adverse events.

      Wijn, Dirk H; Groeneveld, Geert H; Vollaard, Albert M; Muller, Mirte; Wallinga, Jacco; Gelderblom, Hans; Smit, Egbert F (2018-11-01)
      Influenza vaccination is recommended in patients with cancer to reduce influenza-related complications. Recently, more immune-related adverse events (irAEs) were demonstrated in patients with lung cancer who were vaccinated with the trivalent seasonal influenza vaccine during anti-programmed death receptor 1 (PD-1) immunotherapy. Confirmation of these findings is essential before recommendations on influenza vaccination may be revoked. In this cohort study in patients with lung cancer receiving nivolumab 3 mg/kg every 2 weeks during two influenza seasons (2015/16-2016/17), irAEs have been monitored. Incidence, timing and severity of irAEs were compared between vaccinated patients and non-vaccinated patients. In a compassionate use programme, 127 patients with lung cancer had been treated with at least one dose of nivolumab during two national influenza vaccination campaigns from September until December of 2015 and 2016. Forty-two patients had received the influenza vaccine, and 85 patients were not vaccinated. Median follow-up period was 118 days (interquartile range 106-119). Mean age was 64 years (range 46-83). In vaccinated and non-vaccinated patients, the incidence of irAEs was 26% and 22%, respectively, rate ratio 1.20 (95% confidence interval [CI] 0.51-2.65). The incidence of serious irAEs was 7% and 4%, respectively, rate ratio 2.07 (95% CI 0.28-15.43). Influenza vaccination while receiving nivolumab did not result in significant differences in the rates of discontinuation, death, clinical deterioration or tumour response between the groups. Influenza vaccination in patients with lung cancer receiving anti-PD-1 immunotherapy does not induce irAEs in our cohort. With this result, influenza vaccination should not be deterred from this group of patients.
    • Influenza vaccine effectiveness estimates against influenza A(H3N2) and A(H1N1) pdm09 among children during school-based outbreaks in the 2016-2017 season in Beijing, China.

      Zhang, Li; van der Hoek, Wim; Krafft, Thomas; Pilot, Eva; Asten, Liselotte van; Lin, Ge; Wu, Shuangsheng; Duan, Wei; Yang, Peng; Wang, Quanyi (2019-10-09)
      Background: Since 2007, trivalent inactivated influenza vaccine (TIV) has been provided free-of-charge to primary, middle school and high school students in Beijing. However, there have been few school-based studies on influenza vaccine effectiveness (VE). In this report we estimated influenza VE against laboratory-confirmed influenza illness among school children in Beijing, China during the 2016-2017 influenza season. Methods: The VE of 2016-2017 TIV against laboratory-confirmed influenza virus infection among school-age children was assessed through a case-control design. Conditional logistic regression was conducted on matched case-control sets to estimate VE. The effect of prior vaccination on current VE was also examined. Results: All 176 samples tested positive for influenza A virus with the positive rate of 55.5%. The average coverage rate of 2016-2017 TIV among students across the 37 schools was 30.6%. The fully adjusted VE of 2016-2017 TIV against laboratory-confirmed influenza was 69% (95% CI: 51 to 81): 60% (95% CI: -15 to 86) for influenza A(H1N1)pdm09 and 73% (95% CI: 52 to 84) for influenza A(H3N2). The overall VE for receipt of 2015-2016 vaccination only, 2016-2017 vaccination only, and vaccinations in both seasons was 46% (95% CI: -5 to 72), 77% (95% CI: 58 to 87), and 57% (95%CI: 17 to 78), respectively. Conclusions: Our study during school outbreaks found that VE of 2016-2017 TIV was moderate against influenza A(H3N2) as well as A(H1N1)pdm09viruses.
    • Influenza vaccine effectiveness estimates in the Dutch population from 2003 to 2014: The test-negative design case-control study with different control groups.

      van Doorn, Eva; Darvishian, Maryam; Dijkstra, Frederika; Donker, Gé A; Overduin, Pieter; Meijer, Adam; Hak, Eelko (2017-05-15)
      Information about influenza vaccine effectiveness (IVE) is important for vaccine strain selection and immunization policy decisions. The test-negative design (TND) case-control study is commonly used to obtain IVE estimates. However, the definition of the control patients may influence IVE estimates. We have conducted a TND study using the Dutch Sentinel Practices of NIVEL Primary Care Database which includes data from patients who consulted the General Practitioner (GP) for an episode of acute influenza-like illness (ILI) or acute respiratory infection (ARI) with known influenza vaccination status. Cases were patients tested positive for influenza virus. Controls were grouped into those who tested (1) negative for influenza virus (all influenza negative), (2) negative for influenza virus, but positive for respiratory syncytial virus, rhinovirus or enterovirus (non-influenza virus positive), and (3) negative for these four viruses (pan-negative). We estimated the IVE over all epidemic seasons from 2003/2004 through 2013/2014, pooled IVE for influenza vaccine partial/full matched and mismatched seasons and the individual seasons using generalized linear mixed-effect and multiple logistic regression models. The overall IVE adjusted for age, GP ILI/ARI diagnosis, chronic disease and respiratory allergy was 35% (95% CI: 15-48), 64% (95% CI: 49-75) and 21% (95% CI: -1 to 39) for all influenza negative, non-influenza virus positive and pan-negative controls, respectively. In both the main and subgroup analyses IVE estimates were the highest using non-influenza virus positive controls, likely due to limiting inclusion of controls without laboratory-confirmation of a virus causing the respiratory disease.