Patients with Mycobacterium tuberculosis isolates sharing identical DNA fingerprint patterns can be epidemiologically linked. However, municipal health services in the Netherlands are able to confirm ...an epidemiological link in only around 23% of the patients with isolates clustered by the conventional variable number of tandem repeat (VNTR) genotyping. This research aims to investigate whether whole genome sequencing (WGS) is a more reliable predictor of epidemiological links between tuberculosis patients than VNTR genotyping.
VNTR genotyping and WGS were performed in parallel on all Mycobacterium tuberculosis complex isolates received at the Netherlands National Institute for Public Health and the Environment in 2016. Isolates were clustered by VNTR when they shared identical 24-loci VNTR patterns; isolates were assigned to a WGS cluster when the pair-wise genetic distance was ≤ 12 single nucleotide polymorphisms (SNPs). Cluster investigation was performed by municipal health services on all isolates clustered by VNTR in 2016. The proportion of epidemiological links identified among patients clustered by either method was calculated.
In total, 535 isolates were genotyped, of which 25% (134/535) were clustered by VNTR and 14% (76/535) by WGS; the concordance between both typing methods was 86%. The proportion of epidemiological links among WGS clustered cases (57%) was twice as common than among VNTR clustered cases (31%).
When WGS was applied, the number of clustered isolates was halved, while all epidemiologically linked cases remained clustered. WGS is therefore a more reliable tool to predict epidemiological links between tuberculosis cases than VNTR genotyping and will allow more efficient transmission tracing, as epidemiological investigations based on false clustering can be avoided.
Background. Because there may be substantial hidden mortality caused by common seasonal pathogens, we estimated the number of deaths in elderly persons attributable to viruses and bacteria for which ...robust weekly laboratory surveillance data were available. Methods. On weekly time series (1999-2007) we used regression models to associate total death counts in individuals aged 65-74, 75-84, and ≥85 years (a population of 2.5 million) with pathogen circulation—influenza A (season-specific), influenza B, respiratory syncytial virus (RSV), parainfluenza, enterovirus, rotavirus, norovirus, Campylobacter, and Salmonella — adjusted for extreme outdoor temperatures. Results. Influenza A and RSV were significantly (P <.05) associated with mortality in all studied age groups; influenza B and parainfluenza were additionallyassociated in those aged ≥75 years, and norovirus was additionally associated in those aged ≥85 years. The proportions of deaths attributable to seasonal viruses were 6.8% (≥85 years), 4.4% (75-84 years), and 1.4% (65-74 years), but with great variations between years. Influenza occasionally showed lower impact than some of the other viruses. Conclusions. The number of different pathogens associated with mortality in the older population increases with increasing age. Besides influenza A and RSV, influenza B, parainfluenza and norovirus may also contribute substantially to elderly mortality.
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.
Brucellosis is a worldwide zoonosis with significant impact on rural livelihoods and a potentially underestimated contributor to febrile illnesses. The aim of this study was to estimate the ...seroprevalence of brucellosis in humans and small ruminants in The Gambia.
The study was carried out in rural and urban areas. In 12 rural villages in Kiang West district, sera were collected from humans (n = 599) and small ruminants (n = 623) from the same compounds. From lactating small ruminants, milk samples and vaginal swabs were obtained. At the urban study sites, sera were collected from small ruminants (n = 500) from slaughterhouses and livestock markets. Information on possible risk factors for seropositivity was collected through questionnaires. Sera were screened for antibodies against Brucella spp. with the Rose Bengal Test, ELISA and Micro Agglutination Test (human sera only). PCR was performed on 10 percent of the milk samples and vaginal swabs from small ruminants.
One human and 14 sheep sera were positive by the Rose Bengal Test. The rest were negative in all serological tests used. The PCR results were all negative.
The results suggest that brucellosis is currently not a generalized problem in humans or small ruminants in The Gambia.
In the transformation from tidal systems to freshwater coastal landscapes, plants act as eco‐engineering species that reduce hydrodynamics and trap sediment, but nature and timing of the mechanisms ...of land creation along estuaries remains unclear. This article focuses on the Old Rhine estuary (The Netherlands) to show the importance of vegetation in coastal landscape evolution, predominantly regarding tidal basin filling and overbank morphology. This estuary hosted the main outflow channel of the river Rhine between ca 6500 to 2000 cal bp, and was constrained by peat during most of its existence. This study reconstructs its geological evolution, by correlating newly integrated geological data and new field records to varying conditions. Numerical modelling was performed to test the inferred mechanisms. It was found that floodbasin vegetation and resulting organic accumulation strongly accelerated back‐barrier infill, by minimizing tidal influence. After tidal and wave transport had already sufficiently filled the back‐barrier basin, reed rapidly expanded from its edges under brackish conditions, as shown by diatom analysis and datings. Reed growth provided a positive infilling feedback by reducing tidal flow and tidal prism, accelerating basin infilling. New radiocarbon dates show that large‐scale crevassing along the Old Rhine River – driven by tidal backwater effect – only started as nutrient‐rich river water transformed the floodbasin into an Alder carr in a next phase of estuary evolution. Such less dense vegetation promotes crevassing as sediments are more easily transported into the floodbasin. As river discharge increased and estuary mouth infilling progressed, crevasse activity diminished around 3800 to 3000 cal bp, likely due to a reduced tidal backwater effect. The insights from this data‐rich Holocene study showcase the dominant role that vegetation may have in the long‐term evolution of coastal wetlands. It provides clues for effective use of vegetation in vulnerable wetland landscapes to steer sedimentation patterns to strategically adapt to rising water levels.
The incidence of childhood overweight and obesity is rising. It is hypothesized that infections in early childhood are associated with being overweight. This study investigated the association ...between the number of symptomatic infections or antibiotic prescriptions in the first 3 years of life and body mass index (BMI) in adolescence.
The current study is part of the Prevention and Incidence of Asthma and Mite Allergy population-based birth cohort study. Weight and height were measured by trained research staff at ages 12 and 16 years. The 3015 active participants at age 18 years were asked for informed consent for general practitioner (GP) data collection and 1519 gave written informed consent. Studied exposures include (1) GP-diagnosed infections, (2) antibiotic prescriptions, and (3) parent-reported infections in the first 3 years of life. Generalized estimating equation analysis was used to determine the association between each of these exposures and BMI z-score.
Exposure data and BMI measurement in adolescence were available for 622 participants. The frequencies of GP-diagnosed infections and antibiotic prescriptions were not associated with BMI z-score in adolescence with estimates being 0.14 (95% CI -0.09-0.37) and 0.10 (95% CI -0.14-0.34) for the highest exposure categories, respectively. Having ≥6 parent-reported infections up to age 3 years was associated with a 0.23 (95% CI 0.01-0.44) higher BMI z-score compared to <2 parent-reported infections.
For all infectious disease measures an increase in BMI z-score for the highest childhood exposure to infectious disease was observed, although only statistically significant for parent-reported infections. These results do not show an evident link with infection severity, but suggest a possible cumulative effect of repeated symptomatic infections on overweight development.
We assessed the severity of the 2009 influenza pandemic by comparing pandemic mortality to seasonal influenza mortality. However, reported pandemic deaths were laboratory-confirmed - and thus an ...underestimation - whereas seasonal influenza mortality is often more inclusively estimated. For a valid comparison, our study used the same statistical methodology and data types to estimate pandemic and seasonal influenza mortality.
We used data on all-cause mortality (1999-2010, 100% coverage, 16.5 million Dutch population) and influenza-like-illness (ILI) incidence (0.8% coverage). Data was aggregated by week and age category. Using generalized estimating equation regression models, we attributed mortality to influenza by associating mortality with ILI-incidence, while adjusting for annual shifts in association. We also adjusted for respiratory syncytial virus, hot/cold weather, other seasonal factors and autocorrelation. For the 2009 pandemic season, we estimated 612 (range 266-958) influenza-attributed deaths; for seasonal influenza 1,956 (range 0-3,990). 15,845 years-of-life-lost were estimated for the pandemic; for an average seasonal epidemic 17,908. For 0-4 yrs of age the number of influenza-attributed deaths during the pandemic were higher than in any seasonal epidemic; 77 deaths (range 61-93) compared to 16 deaths (range 0-45). The ≥75 yrs of age showed a far below average number of deaths. Using pneumonia/influenza and respiratory/cardiovascular instead of all-cause deaths consistently resulted in relatively low total pandemic mortality, combined with high impact in the youngest age category.
The pandemic had an overall moderate impact on mortality compared to 10 preceding seasonal epidemics, with higher mortality in young children and low mortality in the elderly. This resulted in a total number of pandemic deaths far below the average for seasonal influenza, and a total number of years-of-life-lost somewhat below average. Comparing pandemic and seasonal influenza mortality as in our study will help assessing the worldwide impact of the 2009 pandemic.
The controversial Younger Dryas impact hypothesis suggests that at the onset of the Younger Dryas an extraterrestrial impact over North America caused a global catastrophe. The main evidence for this ...impact—after the other markers proved to be neither reproducible nor consistent with an impact—is the alleged occurrence of several nanodiamond polymorphs, including the proposed presence of lonsdaleite, a shock polymorph of diamond. We examined the Usselo soil horizon at Geldrop-Aalsterhut (The Netherlands), which formed during the Allerød/Early Younger Dryas and would have captured such impact material. Our accelerator mass spectrometry radiocarbon dates of 14 individual charcoal particles are internally consistent and show that wildfires occurred well after the proposed impact. In addition we present evidence for the occurrence of cubic diamond in glass-like carbon. No lonsdaleite was found. The relation of the cubic nanodiamonds to glass-like carbon, which is produced during wildfires, suggests that these nanodiamonds might have formed after, rather than at the onset of, the Younger Dryas. Our analysis thus provides no support for the Younger Dryas impact hypothesis.
Abstract
We describe the Q fever epidemic in the Netherlands with emphasis on the epidemiological characteristics of acute Q fever patients and the association with veterinary factors. Data from 3264 ...notifications for acute Q fever in the period from 2007 through 2009 were analysed. The patients most affected were men, smokers and persons aged 40-60 years. Pneumonia was the most common clinical presentation (62% in 2007 and 2008). Only 3.2% of the patients were working in the agriculture sector and 0.5% in the meat-processing industry including abattoirs. Dairy goat farms with Coxiella burnetii-induced abortion waves were mainly located in the same area where human cases occurred. Airborne transmission of contaminated dust particles from commercial dairy goat farms in densely populated areas has probably caused this epidemic. In 2010, there was a sharp decline in the number of notified cases following the implementation of control measures on dairy goat and sheep farms such as vaccination, hygiene measures and culling of pregnant animals on infected farms. In combination with a rise in the human population with antibodies against C. burnetii, these have most likely ended the outbreak. Development of chronic Q fever in infected patients remains an important problem for years to come.
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