• Acarological Risk of Borrelia burgdorferi Sensu Lato Infections Across Space and Time in The Netherlands.

      Takken, Willem; van Vliet, Arnold J H; Verhulst, Niels O; Jacobs, Frans H H; Gassner, Fedor; Hartemink, Nienke; Mulder, Sara; Sprong, Hein (2017)
      A longitudinal investigation on tick populations and their Borrelia infections in the Netherlands was undertaken between 2006 and 2011 with the aim to assess spatial and temporal patterns of the acarological risk in forested sites across the country and to assess variations in Borrelia genospecies diversity. Ticks were collected monthly in 11 sites and nymphs were examined for Borrelia infections. Tick populations expressed strong seasonal variations, with consistent and significant differences in mean tick densities between sites. Borrelia infections were present in all study sites, with a site-specific mean prevalence per month ranging from 7% to 26%. Prevalence was location-dependent and was not associated with tick densities. Mean Borrelia prevalence was lowest in January (4%), gradually increasing to reach a maximum (24%) in August. Borrelia afzelii represented 70% of all infections, with Borrelia burgdorferi sensu stricto, Borrelia garinii, and Borrelia valaisiana represented with 4%, 8%, and 10%, respectively. The density of infected nymphs and the proportional distribution of the four Borrelia genospecies, were significantly different between sites. The results show a consistent and significant spatial and temporal difference in acarological risk across the Netherlands.
    • 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; et al. (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.
    • Influenza-like Illness Incidence Is Not Reduced by Influenza Vaccination in a Cohort of Older Adults, Despite Effectively Reducing Laboratory-Confirmed Influenza Virus Infections.

      van Beek, Josine; Veenhoven, Reinier H; Bruin, Jacob P; van Boxtel, Renée A J; de Lange, Marit M A; Meijer, Adam; Sanders, Elisabeth A M; Rots, Nynke Y; Luytjes, Willem (2017-08-15)
      Data on the relative contribution of influenza virus and other respiratory pathogens to respiratory infections in community-dwelling older adults (≥60 years) are needed.
    • Road traffic noise and registry based use of sleep medication.

      Evandt, Jorunn; Oftedal, Bente; Krog, Norun Hjertager; Skurtveit, Svetlana; Nafstad, Per; Schwarze, Per E; Skovlund, Eva; Houthuijs, Danny; Aasvang, Gunn Marit (2017-10-23)
      Road traffic noise has been associated with adverse health effects including sleep disturbances. Use of sleep medication as an indicator of sleeping problems has rarely been explored in studies of the effects of traffic noise. Furthermore, using registry data on sleep medications provides an opportunity to study the effects of noise on sleep where attribution of sleep problems to noise is not possible.
    • Space-time analysis of pneumonia hospitalisations in the Netherlands.

      Benincà, Elisa; van Boven, Michiel; Hagenaars, Thomas; van der Hoek, Wim (2017)
      Community acquired pneumonia is a major global public health problem. In the Netherlands there are 40,000-50,000 hospital admissions for pneumonia per year. In the large majority of these hospital admissions the etiologic agent is not determined and a real-time surveillance system is lacking. Localised and temporal increases in hospital admissions for pneumonia are therefore only detected retrospectively and the etiologic agents remain unknown. Here, we perform spatio-temporal analyses of pneumonia hospital admission data in the Netherlands. To this end, we scanned for spatial clusters on yearly and seasonal basis, and applied wavelet cluster analysis on the time series of five main regions. The pneumonia hospital admissions show strong clustering in space and time superimposed on a regular yearly cycle with high incidence in winter and low incidence in summer. Cluster analysis reveals a heterogeneous pattern, with most significant clusters occurring in the western, highly urbanised, and in the eastern, intensively farmed, part of the Netherlands. Quantitatively, the relative risk (RR) of the significant clusters for the age-standardised incidence varies from a minimum of 1.2 to a maximum of 2.2. We discuss possible underlying causes for the patterns observed, such as variations in air pollution.
    • Variation in loss of immunity shapes influenza epidemics and the impact of vaccination.

      Woolthuis, Rutger G; Wallinga, Jacco; van Boven, Michiel (2017-09-19)
      Protective antibody immunity against the influenza A virus wanes in 2-7 years due to antigenic drift of the virus' surface proteins. The duration of immune protection is highly variable because antigenic evolution of the virus is irregular. Currently, the variable nature of the duration of immunity has had little attention in analyses of the impact of vaccination, including cost-effectiveness studies.