• Age-specific Incidence and Prevalence of Keratoconus: A Nationwide Registration Study.

      Godefrooij, Daniel A; de Wit, G Ardine; Uiterwaal, Cuno S; Imhof, Saskia M; Wisse, Robert P L (2017-03)
      To determine the age-specific incidence and prevalence of keratoconus in the modern era of diagnostics.
    • Air Pollution from Livestock Farms Is Associated with Airway Obstruction in Neighboring Residents.

      Borlée, Floor; Yzermans, C Joris; Aalders, Bernadette; Rooijackers, Jos; Krop, Esmeralda; Maassen, Catharina B M; Schellevis, François; Brunekreef, Bert; Heederik, Dick; Smit, Lidwien A M (2017-11-01)
      Livestock farm emissions may not only affect respiratory health of farmers but also of neighboring residents.
    • Associations between lifestyle and air pollution exposure: Potential for confounding in large administrative data cohorts.

      Strak, Maciej; Janssen, Nicole; Beelen, Rob; Schmitz, Oliver; Karssenberg, Derek; Houthuijs, Danny; van den Brink, Carolien; Dijst, Martin; Brunekreef, Bert; Hoek, Gerard (2017)
      Cohorts based on administrative data have size advantages over individual cohorts in investigating air pollution risks, but often lack in-depth information on individual risk factors related to lifestyle. If there is a correlation between lifestyle and air pollution, omitted lifestyle variables may result in biased air pollution risk estimates. Correlations between lifestyle and air pollution can be induced by socio-economic status affecting both lifestyle and air pollution exposure.
    • Associations between lifestyle factors and an unhealthy diet.

      Fransen, Heidi P; Boer, Jolanda M A; Beulens, Joline W J; de Wit, G Ardine; Bueno-de-Mesquita, H Bas; Hoekstra, Jeljer; May, Anne M; Peeters, Petra H M (2017)
      : Unhealthy dietary patterns have been associated with other unhealthy lifestyle factors such as smoking and physical inactivity. Whether these associations are similar in high- and low-educated individuals is currently unknown.
    • Consumption of whole grains, fruit and vegetables is not associated with indices of renal function in the population-based longitudinal Doetinchem study.

      Herber-Gast, Gerrie-Cor M; Boersma, Marijke; Verschuren, W M Monique; Stehouwer, Coen D A; Gansevoort, Ron T; Bakker, Stephan J L; Spijkerman, Annemieke M W (2017-09)
      Emerging evidence suggests that diet and renal function are related. Little is known, however, about the association of consumption of whole grains, fruit and vegetables with urinary albumin:creatinine ratio (ACR) and changes in estimated glomerular filtration rate (eGFR). We investigated this in a population-based cohort aged 26-65 years. Data were from 3787 participants from the Doetinchem cohort study, who were examined ≥3 times, 5 years apart. Consumption of food groups was assessed at each round with a validated FFQ. GFR was estimated at each round from routinely measured cystatin C and creatinine using the Chronic Kidney Disease-Epidemiology (CKD-EPI) equation. ACR was measured at the last round. Generalised estimated equation models were performed to examine associations with changes in eGFR. Linear regression was used to examine associations with ACR. Adjustments were made for covariates related to lifestyle, biological factors and diet. Mean baseline eGFR was 104·5 (sd 13·7) and mean annual decline was -0·95 (sd 0·67) ml/min per 1·73 m2 over a 15-year follow-up. A trend was observed towards slightly less annual decline in eGFR among those with higher consumption of whole grains (P=0·06). This association, however, was attenuated and no longer significant in multivariate models (P=0·29). Consumption of fruit and vegetables was not associated with changes in eGFR and urinary ACR. In conclusion, consumption of whole grains, fruit and vegetables is not associated with changes in eGFR and mean ACR. As this was the first longitudinal study into this association in the general population, and as results are only partially in line with related studies, further research is recommended.
    • Cost-Effectiveness Analysis of Corneal Collagen Crosslinking for Progressive Keratoconus.

      Godefrooij, Daniel A; Mangen, Marie-Josee J; Chan, Elsie; O'Brart, David P S; Imhof, Saskia M; de Wit, G Ardine; Wisse, Robert P L (2017-10)
      To evaluate the cost effectiveness of corneal collagen crosslinking (CXL) for progressive keratoconus from the healthcare payer's perspective.
    • Coxiella burnetii (Q fever) prevalence in associated populations of humans and small ruminants in The Gambia.

      Bok, Jeroen; Hogerwerf, Lenny; Germeraad, Eveline A; Roest, Hendrik I J; Faye-Joof, Tisbeh; Jeng, Momodou; Nwakanma, Davis; Secka, Arss; Stegeman, Arjan; Goossens, Bart; Wegmüller, Rita; van der Sande, Marianne A B; van der Hoek, Wim; Secka, Ousman (2017)
      To simultaneously estimate the prevalence of antibodies against Coxiella burnetii (Q fever) among adults and small ruminants, and C. burnetii shedding prevalence among small ruminants in households in the Kiang West district of The Gambia, and to assess associated risk factors.
    • Decreased, but still sufficient, iodine intake of children and adults in the Netherlands.

      Verkaik-Kloosterman, Janneke; Buurma-Rethans, Elly J M; Dekkers, Arnold L M; van Rossum, Caroline T M (2017-04)
      Sufficient I intake is important for the synthesis of thyroid hormones, which play an important role in normal growth and development. Our aim was to estimate habitual I intake for the Dutch population and the risk of inadequate or excessive intakes. Further, we aimed to provide an insight into the dietary sources of I and the association with socio-demographic factors. Data from the Dutch National Food Consumption Survey 2007-2010 (n 3819; 7-69 years), and from the Dutch food and supplement composition tables were used to estimate habitual I intake with a calculation model. Contribution of food groups to I intake were computed and multiple linear regression was used to examine associations of intakes with socio-demographic factors. A total of ≤2 % of the population had an intake below the estimated average requirement or above the upper level. The main sources of I were bread containing iodised salt (39 %), dairy products (14 %) and non-alcoholic drinks (6 %). I intake (natural sources only, excluding iodised salt and supplements) was positively associated with (parental) education, which could at least partly be attributed to a higher consumption of dairy products. Among children, the consumption of bread, often containing iodised bakery salt, was positively associated with parental education. The I intake of the Dutch population (7-69 years) seems adequate, although it has decreased since the period before 2008. With the current effort to reduce salt intake and changing dietary patterns (i.e. less bread, more organic foods) it is important to keep a close track on the I status, important sources and potential risk groups.
    • Distribution of serotypes and patterns of antimicrobial resistance among commensal Streptococcus pneumoniae in nine European countries.

      Yahiaoui, Rachid Y; Bootsma, Hester J; den Heijer, Casper D J; Pluister, Gerlinde N; John Paget, W; Spreeuwenberg, Peter; Trzcinski, Krzysztof; Stobberingh, Ellen E (2018-08-29)
      Streptococcus pneumoniae is a commensal of the human upper respiratory tract and a major cause of morbidity and mortality worldwide. This paper presents the distribution of serotypes and antimicrobial resistance in commensal S. pneumoniae strains cultured from healthy carriers older than four years of age in nine European countries.
    • Does a better adherence to dietary guidelines reduce mortality risk and environmental impact in the Dutch sub-cohort of the European Prospective Investigation into Cancer and Nutrition?

      Biesbroek, Sander; Verschuren, W M Monique; Boer, Jolanda M A; van de Kamp, Mirjam E; van der Schouw, Yvonne T; Geelen, Anouk; Looman, Moniek; Temme, Elisabeth H M (2017-07)
      Guidelines for a healthy diet aim to decrease the risk of chronic diseases. It is unclear as to what extent a healthy diet is also an environmentally friendly diet. In the Dutch sub-cohort of the European Prospective Investigation into Cancer and Nutrition, the diet was assessed with a 178-item FFQ of 40 011 participants aged 20-70 years between 1993 and 1997. The WHO's Healthy Diet Indicator (HDI), the Dietary Approaches to Stop Hypertension (DASH) score and the Dutch Healthy Diet index 2015 (DHD15-index) were investigated in relation to greenhouse gas (GHG) emissions, land use and all-cause mortality risk. GHG emissions were associated with HDI scores (-3·7 % per sd increase (95 % CI -3·4, -4·0) for men and -1·9 % (95 % CI -0·4, -3·4) for women), with DASH scores in women only (1·1 % per sd increase, 95 % CI 0·9, 1·3) and with DHD15-index scores (-2·5 % per sd increase (95 % CI -2·2, -2·8) for men and -2·0 % (95 % CI -1·9, -2·2) for women). For all indices, higher scores were associated with less land use (ranging from -1·3 to -3·1 %). Mortality risk decreased with increasing scores for all indices. Per sd increase of the indices, hazard ratios for mortality ranged from 0·88 (95 % CI 0·82, 0·95) to 0·96 (95 % CI 0·92, 0·99). Our results showed that adhering to the WHO and Dutch dietary guidelines will lower the risk of all-cause mortality and moderately lower the environmental impact. The DASH diet was associated with lower mortality and land use, but because of high dairy product consumption in the Netherlands it was also associated with higher GHG emissions.
    • Estimated incidence and number of outpatient visits for seasonal influenza in 2015-2016 in Beijing, China.

      Wu, S; Van Asten, L; Wang, L; McDonald, S A; Pan, Y; Duan, W; Zhang, L; Sun, Y; Zhang, Y; Zhang, X; Pilot, E; Krafft, T; Van Der Hoek, W; Van Der Sande, M A B; Yang, P; Wang, Q (2017)
      Information on morbidity burden of seasonal influenza in China is limited. A multiplier model was used to estimate the incidence and number of outpatient visits for seasonal influenza by age group for the 2015-2016 season in Beijing, the capital of China, based on reported numbers of influenza-like illness consultations and proportions of positive cases from influenza surveillance systems in Beijing, general consultation rates and other parameters from previous studies, surveys and surveillance systems. An estimated total of 1 190 200 (95% confidence interval (CI) 830 400-1 549 900) cases of influenza virus infections occurred in Beijing, 2015-2016 season, with an attack rate of 5·5% (95% CI 3·9-7·2%). These infections resulted in an estimated 468 280 (95% CI 70 700-606 800) outpatient visits, with an attack rate of 2·2% (95% CI 0·3-2·8%). The attack rate of influenza virus infections was highest among children aged 0-4 years (31·9% (95% CI 21·9-41·9%)), followed by children aged 5-14 years (18·7% (95% CI 12·9-24·5%)). Our study demonstrated a substantial influenza-related morbidity in Beijing, China, especially among the preschool- and school-aged children. This suggests that development or modification of seasonal influenza targeted vaccination strategies need to recognize that incidence is highest in children.
    • Estimation of age-specific rates of reactivation and immune boosting of the varicella zoster virus.

      Marinelli, Isabella; van Lier, Alies; de Melker, Hester; Pugliese, Andrea; van Boven, Michiel (2017)
      Studies into the impact of vaccination against the varicella zoster virus (VZV) have increasingly focused on herpes zoster (HZ), which is believed to be increasing in vaccinated populations with decreasing infection pressure. This idea can be traced back to Hope-Simpson's hypothesis, in which a person's immune status determines the likelihood that he/she will develop HZ. Immunity decreases over time, and can be boosted by contact with a person experiencing varicella (exogenous boosting) or by a reactivation attempt of the virus (endogenous boosting). Here we use transmission models to estimate age-specific rates of reactivation and immune boosting, exogenous as well as endogenous, using zoster incidence data from the Netherlands (2002-2011, n=7026). The boosting and reactivation rates are estimated with splines, enabling these quantities to be optimally informed by the data. The analyses show that models with high levels of exogenous boosting and estimated or zero endogenous boosting, constant rate of loss of immunity, and reactivation rate increasing with age (to more than 5% per year in the elderly) give the best fit to the data. Estimates of the rates of immune boosting and reactivation are strongly correlated. This has important implications as these parameters determine the fraction of the population with waned immunity. We conclude that independent evidence on rates of immune boosting and reactivation in persons with waned immunity are needed to robustly predict the impact of varicella vaccination on the incidence of HZ.
    • Excess all-cause and influenza-attributable mortality in Europe, December 2016 to February 2017.

      Vestergaard, Lasse S; Nielsen, Jens; Krause, Tyra G; Espenhain, Laura; Tersago, Katrien; Bustos Sierra, Natalia; Denissov, Gleb; Innos, Kaire; Virtanen, Mikko J; Fouillet, Anne; Lytras, Theodore; Paldy, Anna; Bobvos, Janos; Domegan, Lisa; O'Donnell, Joan; Scortichini, Matteo; de Martino, Annamaria; England, Kathleen; Calleja, Neville; van Asten, Liselotte; Teirlinck, Anne C; Tønnessen, Ragnhild; White, Richard A; P Silva, Susana; Rodrigues, Ana P; Larrauri, Amparo; Leon, Inmaculada; Farah, Ahmed; Junker, Christoph; Sinnathamby, Mary; Pebody, Richard G; Reynolds, Arlene; Bishop, Jennifer; Gross, Diane; Adlhoch, Cornelia; Penttinen, Pasi; Mølbak, Kåre (2017-04-06)
      Since December 2016, excess all-cause mortality was observed in many European countries, especially among people aged ≥ 65 years. We estimated all-cause and influenza-attributable mortality in 19 European countries/regions. Excess mortality was primarily explained by circulation of influenza virus A(H3N2). Cold weather snaps contributed in some countries. The pattern was similar to the last major influenza A(H3N2) season in 2014/15 in Europe, although starting earlier in line with the early influenza season start.
    • Fluidity of the dietary fatty acid profile and risk of coronary heart disease and ischemic stroke: Results from the EPIC-Netherlands cohort study.

      Sluijs, I; Praagman, J; Boer, J M A; Verschuren, W M M; van der Schouw, Y T (2017-09)
      The fluidity of dietary fatty acids consumed has been suggested to inversely affect coronary heart disease (CHD) risk. Lipophilic index (LI) represents overall fluidity of the dietary fatty acid profile. Lipophilic load (LL) represents a combination of overall fluidity and absolute intake of dietary fatty acids. We investigated the relations of dietary LI and LL with risk of CHD and ischemic stroke (iStroke).
    • Frequency and determinants of consistent STI/HIV testing among men who have sex with men testing at STI outpatient clinics in the Netherlands: a longitudinal study.

      Visser, Maartje; Heijne, Janneke C M; Hogewoning, Arjan A; van Aar, Fleur (2017)
      Men who have sex with men (MSM) are at highest risk for STIs and HIV infections in the Netherlands. However, official guidelines on STI testing among MSM are lacking. They are advised to test for STIs at least every six months, but their testing behaviour is not well known. This study aimed to get insight into the proportion and determinants of consistent 6-monthly STI testing among MSM testing at STI outpatient clinics in the Netherlands.
    • Gender asymmetry in concurrent partnerships and HIV prevalence.

      Leung, Ka Yin; Powers, Kimberly A; Kretzschmar, Mirjam (2017)
      The structure of the sexual network of a population plays an essential role in the transmission of HIV. Concurrent partnerships, i.e. partnerships that overlap in time, are important in determining this network structure. Men and women may differ in their concurrent behavior, e.g. in the case of polygyny where women are monogamous while men may have concurrent partnerships. Polygyny has been shown empirically to be negatively associated with HIV prevalence, but the epidemiological impacts of other forms of gender-asymmetric concurrency have not been formally explored. Here we investigate how gender asymmetry in concurrency, including polygyny, can affect the disease dynamics. We use a model for a dynamic network where individuals may have concurrent partners. The maximum possible number of simultaneous partnerships can differ for men and women, e.g. in the case of polygyny. We control for mean partnership duration, mean lifetime number of partners, mean degree, and sexually active lifespan. We assess the effects of gender asymmetry in concurrency on two epidemic phase quantities (R0 and the contribution of the acute HIV stage to R0) and on the endemic HIV prevalence. We find that gender asymmetry in concurrent partnerships is associated with lower levels of all three epidemiological quantities, especially in the polygynous case. This effect on disease transmission can be attributed to changes in network structure, where increasing asymmetry leads to decreasing network connectivity.
    • Heterosubtypic cross-reactivity of HA1 antibodies to influenza A, with emphasis on nonhuman subtypes (H5N1, H7N7, H9N2).

      Te Beest, Dennis E; de Bruin, Erwin; Imholz, Sandra; Koopmans, Marion; van Boven, Michiel (2017)
      Epidemics of influenza A vary greatly in size and age distribution of cases, and this variation is attributed to varying levels of pre-existing immunity. Recent studies have shown that antibody-mediated immune responses are more cross-reactive than previously believed, and shape patterns of humoral immunity to influenza A viruses over long periods. Here we quantify antibody responses to the hemagglutinin subunit 1 (HA1) across a range of subtypes using protein microarray analysis of cross-sectional serological surveys carried out in the Netherlands before and after the A/2009 (H1N1) pandemic. We find significant associations of responses, both within and between subtypes. Interestingly, substantial overall reactivity is observed to HA1 of avian H7N7 and H9N2 viruses. Seroprevalence of H7N7 correlates with antibody titers to A/1968 (H3N2), and is highest in persons born between 1954 and 1969. Seroprevalence of H9N2 is high across all ages, and correlates strongly with A/1957 (H2N2). This correlation is most pronounced in A/2009 (H1N1) infected persons born after 1968 who have never encountered A/1957 (H2N2)-like viruses. We conclude that heterosubtypic antibody cross-reactivity, both between human subtypes and between human and nonhuman subtypes, is common in the human population.
    • HIV testing week 2015: lowering barriers for HIV testing among high-risk groups in Amsterdam.

      Bartelsman, M; Joore, I K; van Bergen, J E; Hogewoning, A A; Zuure, F R; van Veen, M G (2017-08-01)
      Evaluation of the HIV Testing Week (HTW) 2015 in Amsterdam: the number of (positive) tested persons, characteristics and testing history of the tested population, the differences in attendance per location and the healthcare workers' experiences and opinions concerning the HTW.
    • Identification of differences in health impact modelling of salt reduction.

      Hendriksen, Marieke A H; Geleijnse, Johanna M; van Raaij, Joop M A; Cappuccio, Francesco P; Cobiac, Linda C; Scarborough, Peter; Nusselder, Wilma J; Jaccard, Abbygail; Boshuizen, Hendriek C (2017)
      We examined whether specific input data and assumptions explain outcome differences in otherwise comparable health impact assessment models. Seven population health models estimating the impact of salt reduction on morbidity and mortality in western populations were compared on four sets of key features, their underlying assumptions and input data. Next, assumptions and input data were varied one by one in a default approach (the DYNAMO-HIA model) to examine how it influences the estimated health impact. Major differences in outcome were related to the size and shape of the dose-response relation between salt and blood pressure and blood pressure and disease. Modifying the effect sizes in the salt to health association resulted in the largest change in health impact estimates (33% lower), whereas other changes had less influence. Differences in health impact assessment model structure and input data may affect the health impact estimate. Therefore, clearly defined assumptions and transparent reporting for different models is crucial. However, the estimated impact of salt reduction was substantial in all of the models used, emphasizing the need for public health actions.
    • The impact of ambient air pollution on the human blood metabolome.

      Vlaanderen, J J; Janssen, N A; Hoek, G; Keski-Rahkonen, P; Barupal, D K; Cassee, F R; Gosens, I; Strak, M; Steenhof, M; Lan, Q; Brunekreef, B; Scalbert, A; Vermeulen, R C H (2017-07)
      Biological perturbations caused by air pollution might be reflected in the compounds present in blood originating from air pollutants and endogenous metabolites influenced by air pollution (defined here as part of the blood metabolome). We aimed to assess the perturbation of the blood metabolome in response to short term exposure to air pollution.