Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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Prevalence of Leptospira spp. and Seoul hantavirus in brown rats (Rattus norvegicus) in four regions in the Netherlands, 2011-2015
Maas, Miriam ; Vries, Ankje De; Reusken, Chantal ; Buijs, Jan ; Goris, Marga ; Hartskeerl, Rudy ; Ahmed, Ahmed ; Tulden, Peter van; Swart, Arno ; Pijnacker, Roan ; Koene, Miriam ; Lundkvist, Åke ; Heyman, Paul ; Rockx, Barry ; Giessen, Joke Van Der - \ 2018
Infection Ecology and Epidemiology 8 (2018)1.
epidemiology - hantavirus - Leptospirosis - prevalence - Rattus norvegicus - Seoul virus

Background: Brown rats (Rattus norvegicus) may carry pathogens that can be a risk for public health. Brown rats in the Netherlands were tested for the zoonotic pathogens Leptospira spp. and Seoul hantavirus (SEOV), in order to obtain insight in their prevalence. Methods and results: Cross-sectional studies were performed at four locations from 2011 to 2015. The rats were tested for Leptospira spp. using real-time PCR and/or culture resulting in a prevalence ranging between 33–57%. Testing for SEOV was done through an adapted human Seoul hantavirus ELISA and real-time RT-PCR. Although at several locations the ELISA indicated presence of SEOV antibodies, none could be confirmed by focus reduction neutralization testing. Conclusion: The results indicate a widespread presence of Leptospira spp. in brown rats in the Netherlands, including areas with a low leptospirosis incidence in humans. No evidence for circulation of SEOV was found in this study.

Minimum required number of specimen records to develop accurate species distribution models
Proosdij, A.S.J. van; Sosef, M.S.M. ; Wieringa, Jan ; Raes, N. - \ 2015
simulated species - prevalence - AUC - minimum number of records - model performance - null model - species distribution model
Species Distribution Models (SDMs) are widely used to predict the occurrence of species. Because SDMs generally use presence-only data, validation of the predicted distribution and assessing model accuracy is challenging. Model performance depends on both sample size and species’ prevalence, being the fraction of the study area occupied by the species. Here, we present a novel method using simulated species to identify the minimum number of records required to generate accurate SDMs for taxa of different pre-defined prevalence classes. We quantified model performance as a function of sample size and prevalence and found model performance to increase with increasing sample size under constant prevalence, and to decrease with increasing prevalence under constant sample size. The Area Under the Curve (AUC) is commonly used as a measure of model performance. However, when applied to presence-only data it is prevalence-dependent and hence not an accurate performance index. Testing the AUC of an SDM for significant deviation from random performance provides a good alternative. We assessed the minimum number of records required to obtain good model performance for species of different prevalence classes in a virtual study area and in a real African study area. The lower limit depends on the species’ prevalence with absolute minimum sample sizes as low as 3 for narrow-ranged and 13 for widespread species for our virtual study area which represents an ideal, balanced, orthogonal world. The lower limit of 3, however, is flawed by statistical artefacts related to modelling species with a prevalence below 0.1. In our African study area lower limits are higher, ranging from 14 for narrow-ranged to 25 for widespread species. We advocate identifying the minimum sample size for any species distribution modelling by applying the novel method presented here, which is applicable to any taxonomic clade or group, study area or climate scenario.
Methicillin-resistant Staphylococcus aureus and extended-spectrum and AmpC b-lactamase-producing Escherichia coli in broilers and in people living and/or working on organic broiler farms
Huijbers, P.M.C. ; Hoek, A.H.A.M. van; Graat, E.A.M. ; Haenen, A.P.J. ; Florijn, A. ; Hengeveld, P.D. ; Duijkeren, E. van - \ 2015
Veterinary Microbiology 176 (2015)1-2. - ISSN 0378-1135 - p. 120 - 125.
livestock-associated mrsa - risk-factors - prevalence - netherlands - humans
The aim of this study was to estimate the prevalence of methicillin-resistantStaphylococcus aureus (MRSA) and extended-spectrum and AmpC b-lactamase (ESBL/AmpC)-producing Escherichia coli among broilers, and humans living and/or working on organic broiler farms; further characterise isolates; and compare these results with those from conventional farms. In the Netherlands, only 9 certified organic broiler farms were present. On 8 of these farms, 60 throat swabs and 20 cloacal swabs were taken per farm for MRSA and ESBL/AmpC-E. coli detection, respectively, at an average age of both 34 (T1) and 68 (T2) days. Faecal swabs and questionnaires were returned by 27 out of 36 humans. For selected ESBL/AmpC-producing E. coli isolates, phylogenetic groups, b-lactamase genes, plasmid families, and sequence types were determined. MRSA was not detected in broiler and human samples. ESBL/AmpC-producing E. coli were isolated from broilers on 7/8 farms at T1 and on all farms at T2. Furthermore, 3 farmers at T1, and 2 farmers and 1 family member at T2 were positive. Genes found in broilers and humans were almost exclusively blaCTX-M-1 and blaCMY-2. Given the high overall human ESBL/AmpC-prevalence (18.5%), which is similar to conventional farms, contact with live broilers is assumed a risk factor for carriage. Farm and sample-level prevalence at T1 are consistent with those from conventional farms. At T2, just before slaughter, sample-level prevalence of ESBL/AmpC-E. coli appears to have decreased (94.3%vs. 80%), which could have important consequences for contamination of retail meat.
That’s why I take my ONS. Means-end chain as a novel approach to elucidate the personally relevant factors driving ONS consumption in nutritionally frail elderly users
Uijl, L.C. den; Kremer, S. ; Jager, G. ; Stelt, Annelies van der; Graaf, C. de; Gibson, P. ; Godfrey, J. ; Lawlor, J.B. - \ 2015
Appetite 89 (2015). - ISSN 0195-6663 - p. 33 - 40.
sensory attributes - supplements - care - malnutrition - perceptions - prevalence - interview - consumers - motives - drinks
Oral nutritional supplements (ONS) are a recommended form of nutritional intervention for older malnourished persons when a ‘food first’ approach and/or food fortification prove ineffective. The efficacy of ONS will depend on, amongst other factors, whether persons do, or do not, consume their prescribed amount. Factors influencing ONS consumption can be product, context, or person related. Whereas product and context have received some attention, little is known about the person factors driving ONS consumption. In addition, the relative importance of the product, context, and person factors to ONS consumption is not known. Using the means-end chain (MEC) method, the current study elucidated personally relevant factors (product, context, and person factors) related to ONS consumption in two groups of older nutritionally frail ONS users: community-dwelling persons and care home residents with mainly somatic disorders. To our knowledge, the current work is the first to apply the MEC method to study older nutritionally frail ONS users. Forty ONS users (n¿=¿20 per group) were recruited via healthcare professionals. The level of frailty was assessed using the FRAIL scale. Both groups were interviewed for 30 to 45 minutes using the soft laddering technique. The laddering data were analysed using LadderUX software™. The MEC method appeared to work well in both groups. The majority of the participants took ONS on their doctor's or dietician's prescription as they trusted their advice. The community-dwelling group took ONS to prolong their independence, whereas the care home group reported values that related more to small improvements in quality of life. In addition, care home residents perceived themselves as dependent on their caregiver for their ONS arrangements, whereas this dependence was not reported by community-dwelling persons. Key insights from this work will enable doctors and dieticians to customize their nutritional interventions to ONS users' personal needs and thus positively impact health outcomes
Adapting an effective lifestyle intervention towards individuals with low socioeconomic status of different ethnic origins: the design of the MetSLIM study
Teuscher, D. ; Bukman, A.J. ; Meershoek, A. ; Renes, R.J. ; Feskens, E.J.M. ; Baak, M.A. van - \ 2015
BMC Public Health 15 (2015). - ISSN 1471-2458 - 10 p.
tolerance maastricht slim - to-height ratio - glucose-tolerance - risk-factors - cardiovascular-disease - physical-activity - health-promotion - screening tool - implementation - prevalence
Background People with low socioeconomic status (SES) and some ethnic minorities are often underrepresented in lifestyle programmes. Therefore, a lifestyle programme was developed especially targeting these groups. Developing this lifestyle programme and designing an intervention study to test the effectiveness of this programme was an informative process in which several obstacles were encountered and choices had to be made. Study protocols, however, rarely describe these obstacles encountered in the protocol design process, and it is not always clear why researchers made certain choices. Therefore, the aim of this article is to describe both the final MetSLIM study protocol and the considerations and choices made in designing this study protocol. Methods/Design The developed MetSLIM study has a quasi-experimental design, targeting 30- to 70-year-old adults with an elevated waist circumference, living in deprived neighbourhoods, of Dutch, Turkish or Moroccan descent. The intervention group participates in a 12-month lifestyle programme consisting of individual dietary advice, four group sessions and weekly sports lessons. The control group receives written information about a healthy lifestyle and one group session provided by a dietician. The study contains an elaborate effect, process and economic evaluation. Outcome measures are, among other things, change in waist circumference and the other components of the metabolic syndrome. Discussion Matching the preferences of the target group, such as their preferred setting, has implications for the entire study protocol. The process evaluation of the MetSLIM study will provide insight into the consequences of the choices made in the MetSLIM study protocol in terms of reach, acceptability and delivery of the programme, and the effect and economic evaluation will provide insight into the (cost)effectiveness of the lifestyle programme in order to reduce waist circumference among individuals with low SES of different ethnic origins.
Loss of Olfactory Function and Nutritional Status in Vital Older Adults and Geriatric Patients
Toussaint, N. ; Roon, M. de; Campen, J.P.C.M. van; Kremer, S. ; Boesveldt, S. - \ 2015
Chemical Senses 40 (2015)3. - ISSN 0379-864X - p. 197 - 203.
mild cognitive impairment - odor identification - normative data - taste - malnutrition - smell - discrimination - dysfunction - prevalence - validation
The aim of this cross-sectional study was to assess the association of olfactory function and nutritional status in vital older adults and geriatric patients. Three hundred forty-five vital (mean age 67.1 years) and 138 geriatric older adults (mean age 80.9 years) were included. Nutritional status was assessed using the mini nutritional assessment-short form. The Sniffin’ Sticks was used to measure olfactory function. Eleven percentage of the vital older adults were at risk of malnutrition, whereas 60% of the geriatric participants were malnourished or at risk. Only 2% of the vital older adults were anosmic, compared with 46% of the geriatric participants. Linear regression demonstrated a significant association (P = 0.015) between olfactory function and nutritional status in the geriatric subjects. However, this association became insignificant after adjustment for confounders. Both crude and adjusted analysis in the vital older adults did not show a significant association. The results indicate that, in both groups of elderly, there is no direct relation between olfactory function and nutritional status. We suggest that a decline in olfactory function may still be considered as one of the risk-factors for malnutrition in geriatric patients—once co-occurring with other mental and/or physical problems that are more likely to occur in those patients experience.
A weekly alternating diet between caloric restriction and medium-fat protects the liver from fatty liver development in middle-aged C57BL/6J mice
Rusli, F. ; Boekschoten, M.V. ; Zubia, A.A. ; Lute, C. ; Müller, M.R. ; Steegenga, W.T. - \ 2015
Molecular Nutrition & Food Research 59 (2015)3. - ISSN 1613-4125 - p. 533 - 543.
metabolic syndrome - insulin-resistance - small-intestine - induced obesity - adipose-tissue - life-span - disease - prevalence - population - expression
Scope : We aimed to investigate whether a novel dietary intervention consisting of an every-other-week calorie restricted diet could prevent non-alcoholic fatty liver disease (NAFLD) development induced by a medium-fat diet. Methods and results : Nine week-old male C57BL/6J mice received either a 1) control (C), 2) 30E% calorie restricted (CR), 3) medium-fat (MF; 25E% fat) or 4) intermittent (INT) diet, a diet alternating weekly between 40E% CR and an ad libitum MF diet until sacrifice at the age of 12 months. The metabolic, morphological, and molecular features of NAFLD were examined. The INT diet resulted in healthy metabolic and morphological features as displayed by the continuous CR diet: glucose tolerant, low hepatic triglyceride content, low plasma alanine aminotransferase. In contrast, the C- and MF-exposed mice with high body weight developed signs of NAFLD. However, the gene expression profiles of INT-exposed mice differed to those of CR-exposed mice and showed to be more similar with those of C- and MF-exposed mice with a comparable body weight. Conclusions : Our study reveals that the INT diet maintains metabolic health and reverses the adverse effects of the MF diet, thus effectively prevent the development of NAFLD in 12-month-old male C57BL/6J mice.
Development of the HELIUS food frequency questionnaires ethnic-specific questionnaires to assess the diet of a multiethnic population in The Netherlands
Beukers, M.H. ; Dekker, L.H. ; Boer, E.J. de; Perenboom, C.W.M. ; Meijboom, S. ; Nicolaou, M. ; Vries, J.H.M. de; Brants, H.A.M. - \ 2015
European Journal of Clinical Nutrition 69 (2015). - ISSN 0954-3007 - p. 579 - 584.
risk-factors - cardiovascular-disease - health - prevalence - europe - immigrants - chinese - cohort
Objectives: Ethnic minorities are often not included in studies of diet and health because of a lack of validated instruments to assess their habitual diets. Given the increased ethnic diversity in many high-income countries, insight into the diets of ethnic minorities is needed for the development of nutritional policies and interventions. In this paper, we describe the development of ethnic-specific food frequency questionnaires (FFQs) to study the diets of Surinamese (African and South Asian), Turkish, Moroccan and ethnic Dutch residents of The Netherlands. Methods: An existing Dutch FFQ was adapted and formed the basis for three new FFQs. Information on food intake was obtained from single 24¿h recalls. Food items were selected according to their percentage contribution to and variance in absolute nutrient intake of the respective ethnic groups. A nutrient database for each FFQ was constructed, consisting of data from the Dutch Food Composition table; data on ethnic foods were based on new chemical analyses and available international data. Results: We developed four ethnic-specific FFQs using a standardised approach that included ~200 food items each and that covered more than 90% of the intake of the main nutrients of interest. Conclusions: The developed FFQs will enable standardised and comparable assessment of the diet of five different ethnic groups and provide insight into the role of diet in differences in health between ethnic groups. The methodology described in this paper and the choices made during the development phase may be useful in developing similar FFQs in other settings.
Risk perception and management in smallholder dairy farming in Tigray, Northern Ethiopia
Gebreegziabher, K. ; Tadesse Woeldesenbet, T. - \ 2014
Journal of Risk Research 17 (2014)3. - ISSN 1366-9877 - p. 367 - 381.
tick-borne diseases - kenya highlands - cattle - tanzania - systems - prevalence - economics - adoption - farmers - region
Empirical studies on smallholder dairy farmers' risk perceptions and management strategies have still received little attention in agricultural research of developing countries. This study focuses on farmers' risk perception and management strategies of smallholder dairy farms in urban and peri-urban areas of Tigray in northern Ethiopia. Based on data collected from a sample of 304 smallholder dairy farm households, we used descriptive statistics for analyzing farmers' risk attitude and factor analysis for analyzing and classifying risk sources and management strategies. The majority of dairy farmers considered themselves risk takers towards farm decision that may have a positive impact on technology adoption. Factor analysis identified technological, price/market, production, financial, human, and institutional factor as major sources of risks. In addition, factor analysis indicates that disease reduction, diversification, financial management, and market network are perceived as the most effective risk management strategies. Our findings indicate that perceptions of risk and management strategies are farmer-specific; therefore, policy-makers need to consider tailor-made strategies that would address farmers' individual motives to manage risks and shocks.
Cultivation-Independent Screening Revealed Hot Spots of IncP-1, IncP-7 and IncP-9 Plasmid Occurrence in Different Environmental Habitats
Dealtry, S. ; Ding, G.C. ; Weichelt, V. ; Dunon, V. ; Schluter, A. ; Martini, M.C. ; Papa, M.F. Del; Lagares, A. ; Amos, G.C.A. ; Wellington, E.M.H. ; Gaze, W.H. ; Sipkema, D. ; Sjoling, S. ; Springael, D. ; Heuer, H. ; Elsas, J.D. ; Thomas, C. ; Smalla, K. - \ 2014
PLoS ONE 9 (2014)2. - ISSN 1932-6203
resistance genes - naphthalene - pseudomonas - adaptation - prevalence - transposon - diversity - sediment - biobeds
IncP-1, IncP-7 and IncP-9 plasmids often carry genes encoding enzymes involved in the degradation of man-made and natural contaminants, thus contributing to bacterial survival in polluted environments. However, the lack of suitable molecular tools often limits the detection of these plasmids in the environment. In this study, PCR followed by Southern blot hybridization detected the presence of plasmid-specific sequences in total community (TC-) DNA or fosmid DNA from samples originating from different environments and geographic regions. A novel primer system targeting IncP-9 plasmids was developed and applied along with established primers for IncP-1 and IncP-7. Screening TC- DNA from biopurification systems (BPS) which are used on farms for the purification of pesticide-contaminated water revealed high abundances of IncP-1 plasmids belonging to different subgroups as well as IncP-7 and IncP-9. The novel IncP-9 primer-system targeting the rep gene of nine IncP-9 subgroups allowed the detection of a high diversity of IncP-9 plasmid specific sequences in environments with different sources of pollution. Thus polluted sites are "hot spots'' of plasmids potentially carrying catabolic genes.
Antimicrobial resistance in commensal Escherichia coli in veal calves is associated with antimicrobial drug use
Bosman, A.B. ; Wagenaar, J.A. ; Stegeman, J.A. ; Vernooij, J.C.M. ; Mevius, D.J. - \ 2014
Epidemiology and Infection 142 (2014)9. - ISSN 0950-2688 - p. 1893 - 1904.
to-finish farms - antibiotic-resistance - fecal samples - exposed herd - risk-factors - pigs - prevalence - coliforms - bacteria - ontario
The aim of this study was to determine the association between farm management factors, including antimicrobial drug usage, and resistance in commensal Escherichia coli isolates from the faeces of white veal calves. Ninety E. coli isolates from one pooled sample per farm (n = 48) were tested for their phenotypical resistance against amoxicillin, tetracycline, cefotaxime, ciprofloxacin and trimethoprim/sulfamethoxazole (TMP/SMX). Logistic regression analysis revealed the following risk factors (P <0·05); farmer wearing the same work clothes for several days [ciprofloxacin, odds ratio (OR) 2·6; tetracycline, OR 2·4], administration of trimethoprim-sulfonamide combinations (TMP/SMX, OR 3·0; amoxicillin, OR 3·1; tetracycline, OR 2·6), ¿0·3 animal daily dosage per production cycle (ADD/pc), quinolones (ciprofloxacin, OR 2·8), ¿1·3 ADD/pc, penicillins (ciprofloxacin, OR 3·3; tetracycline, OR 3·4), 20-40 ADD/pc, tetracyclines (tetracycline, OR 3·2) and >40 ADD/pc, tetracyclines (tetracycline, OR 13·1; amoxicillin, OR 6·5). In this study antimicrobial resistance in commensal E. coli was mainly associated with antimicrobial drug use.
The impact of double-blind placebo-controlled food challenge (DBPCFC) on the socioeconomic cost of food allergy in Europe
Cerecedo, I. ; Zamora, J. ; Fox, M. ; Voordouw, J. ; Plana, N. ; Rokicka, E. ; Fernandez-Rivas, M. ; Vazquez Cortes, S. ; Reche, M. ; Fiandor, A. ; Kowalski, M. ; Antonides, G. ; Mugford, M. ; Frewer, L.J. ; Hoz, B. De la - \ 2014
Journal of Investigational Allergology & Clinical Immunology 24 (2014)6. - ISSN 1018-9068 - p. 418 - 424.
prevalence - hypersensitivity - sensitization
BACKGROUND: Double-blind placebo controlled food (DBPCFC) is the gold standard diagnostic test in food allergy because it minimizes diagnostic bias. OBJECTIVE: To investigate the potential effect of diagnosis on the socioeconomic costs of food allergy. METHODS: A prospective longitudinal cost analysis study was conducted in Spain and Poland within the EuroPrevall project. Food-allergic patients were enrolled into the study and in all cases diagnosis was confirmed through a standardized DBPCFC. Data were collected through a self-administered survey on all aspects of health and social care resource use, costs of living, and costs of leisure activities. Costs were measured before and 6 months after the DBPCFC and reported in international dollars with 2007 as the benchmark year. RESULTS: Forty-two patients were enrolled. Twenty-one patients had a negative DBPCFC and the suspected food was reintroduced into their diet. Comparing total direct costs before and after the DBPCFC, the reactive group spent a significantly higher amount (median increase of $ 813.1 over baseline), while the tolerant group's spending decreased by a median of $ 87.3 (P=0.31). The amount of money spent on food 6 months after diagnosis was also significantly higher in the reactive group (P=40). Finally, a larger, but not statistically significant, decrease in total indirect costs was observed in the tolerant group compared with the reactive group ($538.3 vs $ 32.3). CONCLUSION: DBPCFC has an impact on indirect and direct costs of living. The main contrubition to this increase was money to spent on food. Keywords: Food allergy. Double-Blind Placebo-Controlled Food Challenge. Diagnosis. Socioeconomic impact.
Comparison of Fecal Methanogenic Archaeal Community Between Erhualian and Landrace Pigs Using Denaturing Gradient Gel Electrophoresis and Real-Time PCR Analysis
Su, Y. ; Smidt, H. ; Zhu, W.Y. - \ 2014
Journal of Integrative Agriculture 13 (2014)6. - ISSN 2095-3119 - p. 1340 - 1348.
16s ribosomal-rna - methanobrevibacter-smithii - human gut - diversity analysis - mcra gene - quantification - populations - bacterial - methane - prevalence
Erhualian and Landrace breeds are typical genetically obese and lean pigs, respectively. To compare the fecal methanogenic Archaeal community between these two pig breeds, fecal samples from different growth phase pigs were collected and used for PCR-denaturing gradient gel electrophoresis (DGGE) with two primer pairs (344fGC/519r and 519f/915rGC) and real-time PCR analysis. Results showed that a better separation and higher quality of bands pattern were obtained in DGGE profiles using primers 344fGC/519r as compared with primers 519f/915rGC. Sequencing of DGGE bands showed that the predominant methanogens in the feces of Erhualian and Landrace pigs belonged to Methanobrevibacter spp. and Methanosphaera spp. Real-time PCR analysis revealed that there was no significant difference in the numbers of fecal total methanogens between Erhualian and Landrace pigs; however, pig growth phase affected the numbers of 16S rRNA genes of total methanogens and Methanobrevibacter smithii. Dissociation curves of methyl coenzyme-M reductase subunit A (mcrA) gene fragments amplified with real-time PCR showed all samples possessed a single peak at 82°C, which might be associated with M. smithii. Samples from the same growth phase of each breed showed good replicative dissociation curves. The results suggest that the growth phase (including diet factor) other than genotype of pig may affect the fecal methanogenic Archaeal community of pigs.
Effect of merging levels of locomotion scores for dairy cows on intra- and interrater reliability and agreement
Schlageter-Tello, A. ; Bokkers, E.A.M. ; Groot Koerkamp, P.W.G. ; Hertem, T. van; Viazzi, S. ; Romanini, C.E.B. ; Halachmi, I. ; Bahr, C. ; Berckmans, D. ; Lokhorst, K. - \ 2014
Journal of Dairy Science 97 (2014)9. - ISSN 0022-0302 - p. 5533 - 5542.
ensure high repeatability - lameness scoring system - sampling strategies - training-program - standard errors - lying behavior - weighted kappa - cattle - prevalence - gait
Locomotion scores are used for lameness detection in dairy cows. In research, locomotion scores with 5 levels are used most often. Analysis of scores, however, is done after transformation of the original 5-level scale into a 4-, 3-, or 2-level scale to improve reliability and agreement. The objective of this study was to evaluate different ways of merging levels to optimize resolution, reliability, and agreement of locomotion scores for dairy cows. Locomotion scoring was done by using a 5-level scale and 10 experienced raters in 2 different scoring sessions from videos from 58 cows. Intra- and interrater reliability and agreement were calculated as weighted kappa coefficient (¿w) and percentage of agreement (PA), respectively. Overall intra- and interrater reliability and agreement and specific intra- and interrater agreement were determined for the 5-level scale and after transformation into 4-, 3-, and 2-level scales by merging different combinations of adjacent levels. Intrarater reliability (¿w) ranged from 0.63 to 0.86, whereas intrarater agreement (PA) ranged from 60.3 to 82.8% for the 5-level scale. Interrater ¿w=0.28 to 0.84 and interrater PA=22.6 to 81.8% for the 5-level scale. The specific intrarater agreement was 76.4% for locomotion level 1, 68.5% for level 2, 65% for level 3, 77.2% for level 4, and 80% for level 5. Specific interrater agreement was 64.7% for locomotion level 1, 57.5% for level 2, 50.8% for level 3, 60% for level 4, and 45.2% for level 5. Specific intra- and interrater agreement suggested that levels 2 and 3 were more difficult to score consistently compared with other levels in the 5-level scale. The acceptance threshold for overall intra- and interrater reliability (¿w and ¿ =0.6) and agreement (PA =75%) and specific intra- and interrater agreement (=75% for all levels within locomotion score) was exceeded only for the 2-level scale when the 5 levels were merged as (12)(345) or (123)(45). In conclusion, when locomotion scoring is performed by experienced raters without further training together, the lowest specific intra- and interrater agreement was obtained in levels 2 and 3 of the 5-level scale. Acceptance thresholds for overall intra- and interrater reliability and agreement and specific intra- and interrater agreement were exceeded only in the 2-level scale.
Blood feeding on large grazers affects the transmission of Borrelia burgdorferi sensu lato by Ixodes ricinus
Pacilly, F.C.A. ; Benning, M.E. ; Jacobs, F. ; Leidekker, J. ; Sprong, H. ; Wieren, S.E. van; Takken, W. - \ 2014
Ticks and Tick-borne Diseases 5 (2014)6. - ISSN 1877-959X - p. 810 - 817.
lyme borreliosis - tick infestation - north-america - endemic area - roe deer - netherlands - prevalence - density - disease - abundance
The presence of Ixodes ricinus and their associated Borrelia infections on large grazers was investigated. Carcases of freshly shot red deer, mouflon and wild boar were examined for the presence of any stage of I. ricinus. Questing ticks were collected from locations where red deer and wild boar are known to occur. Presence of Borrelia burgdorferi s.l. DNA was examined in a fraction of the collected ticks. Larvae, nymphs and adult ticks were found on the three large grazers. Red deer had the highest tick burden, with many of the nymphs and adult females attached for engorgement. Most larvae had not attached. The mean number of ticks on the animals varied from 13 to 67. Ticks were highly aggregated amongst the animals: some animals had no ticks, while others had high numbers. Larvae and nymphs were mostly found on the ears, while adult ticks were attached to the axillae. The Borrelia infection rate of questing nymphs was 8.5%. Unengorged wandering nymphs on deer had a Borrelia infection rate of 12.5%, while only 0.9% of feeding nymphs carried a Borrelia infection. The infection rate of unengorged adult male ticks was 4.5%, and that of feeding female ticks was 0.7%. The data suggest that ticks feeding on red deer and wild boar lose their Borrelia infections. The implications of the results are discussed with respect to Borrelia epidemiology and maintenance of a Borrelia reservoir as well as the role of reproductive hosts for Ixodes ricinus.
Overweight increases risk of trimester hypothyroxinaemia in iodine-deficient pregnant woman
Gowachirapant, S. ; Boonstra, A. ; Winichagoon, P. ; Zimmerman, M.B. - \ 2014
Maternal and Child Nutrition 10 (2014)1. - ISSN 1740-8695 - p. 61 - 71.
maternal hypothyroxinemia - thyroid-disease - free-thyroxine - hypothyroidism - obesity - supplementation - consequences - population - prevalence - management
Hypothyroxinaemia early in pregnancy may impair fetal brain development. Increased body weight has been associated with low thyroxine concentrations in non-pregnant women. In pregnant women, morbid maternal obesity is a risk factor for thyroid dysfunction. But whether lesser degrees of overweight that are much more common could be a risk factor for hypothyroxinaemia in pregnancy is unclear. The objective of this study was to investigate if overweight increases risk for thyroid dysfunction, and specifically hypothyroxinaemia, in iodine-deficient pregnant women. We performed a cross-sectional study at first hospital visit among healthy Thai pregnant women. We measured weight and height, urinary iodine concentration (UIC), serum thyroid hormones and thyroglobulin. Pre-pregnancy weight and relevant dietary factors were determined by questionnaire, and body mass index (BMI) was used to classify weight status. Among 514 women (mean gestational age, 11 weeks) with a median UIC of 111¿µg¿dL–1, indicating mild iodine deficiency, 12% had low free thyroxine (fT4) concentrations: 3% had overt hypothyroidism; 7% had subclinical hypothyroidism; and 8% had isolated hypothyroxinaemia. Based on pre-pregnancy BMI, 26% of women were overweight or obese. In a multiple regression model, BMI was a negative predictor of fT4 (ß¿=¿-0.20, P¿
DHA Serum Levels Were Significantly Higher in Celiac Disease Patients Compared to Healthy Controls and Were Unrelated to Depression
Hees, N.J.M. van; Giltay, E.J. ; Geleijnse, J.M. ; Janssen, N. ; Does, A.J.W. van der - \ 2014
PLoS ONE 9 (2014)5. - ISSN 1932-6203
gluten-free diet - fatty-acid-composition - major depression - body-composition - children - omega-3-fatty-acids - adolescents - prevalence - disorders - diagnosis
Objectives: Celiac disease (CD), a genetically predisposed intolerance for gluten, is associated with an increased risk of major depressive disorder (MDD). We investigated whether dietary intake and serum levels of the essential n-3 polyunsaturated fatty acids (PUFA) eicosapentaenoic acid (EPA) and docosahexanoic acid (DHA) found in fatty fish play a role in this association. Methods: Cross-sectional study in 71 adult CD patients and 31 healthy volunteers, matched on age, gender and level of education, who were not using n-3 PUFA supplements. Dietary intake, as assessed using a 203-item food frequency questionnaire, and serum levels of EPA and DHA were compared in analyses of covariance, adjusting for potential confounders. Serum PUFA were determined using gas chromatography. Results: Mean serum DHA was significantly higher in CD patients (1.72 mass%) than controls (1.28 mass%) after multivariable adjustment (mean diff. 0.45 mass%; 95% CI: 0.22-0.68; p = 0.001). The mean intake of EPA plus DHA did not differ between CD patients and controls after multivariable adjustment (0.15 and 0.22 g/d, respectively; p = 0.10). There were no significant differences in intake or serum levels of EPA and DHA between any of the CD patient groups (never depressed, current MDD, minor/partially remitted MDD, remitted MDD) and controls. Conclusions: Patients on a long term gluten-free diet had similar intakes of EPA plus DHA compared to controls. Contrary to expectations, DHA serum levels were significantly higher in CD patients compared to healthy controls and were unrelated to MDD status.
Estimation of hepatitis E virus (HEV) pig seroprevalence using Elisa and Western blot and comparison between human and pig HEV sequences in Belgium.
Thiry, D. ; Mauroy, A. ; Saegerman, C. ; Thomas, I. ; Wautier, M. ; Miry, C. ; Czaplicki, G. ; Berkvens, D. ; Praet, N. ; Poel, W.H.M. van der; Cariolet, R. ; Brochier, B. ; Thiry, E. - \ 2014
Veterinary Microbiology 172 (2014)3-4. - ISSN 0378-1135 - p. 407 - 414.
antibodies - swine - transmission - infection - netherlands - populations - prevalence - france - meat - farm
Zoonotic transmission of hepatitis E virus (HEV) is of special concern, particularly in high income countries were waterborne infections are less frequent than in developing countries. High HEV seroprevalences can be found in European pig populations. The aims of this study were to obtain prevalence data on HEV infection in swine in Belgium and to phylogenetically compare Belgian human HEV sequences with those obtained from swine. An ELISA screening prevalence of 73% (95% CI 68.8–77.5) was determined in Belgian pigs and a part of the results were re-evaluated by Western blot (WB). A receiver operating characteristic curve analysis was performed and scenarios varying the ELISA specificity relative to WB were analysed. The seroprevalences estimated by the different scenarios ranged between 69 and 81% and are in agreement with the high exposure of the European pig population to HEV. Pig HEV sequences were genetically compared to those detected in humans in Belgium and a predominance of genotype 3 subtype f was shown in both swine and humans. The high HEV seroprevalence in swine and the close phylogenetic relationships between pig and human HEV sequences further support the risk for zoonotic transmission of HEV between humans and pigs.
Survey of the crayfisch plague pathogen presence in the Netherlands reveals a new Aphanomyces astaci carrier.
Tilmans, M.H.J. ; Mrugala, A. ; Svoboda, J. ; Engelsma, M.Y. ; Petie, M. ; Soes, D.M. ; Nutbeam-Tuffs, S. ; Oidtmann, B. ; Roessink, I. ; Petrusek, A. - \ 2014
Journal of Invertebrate Pathology 120 (2014). - ISSN 0022-2011 - p. 74 - 79.
north-american crayfish - polymerase-chain-reaction - fresh-water crayfish - persistent infection - central-europe - populations - prevalence - agent
North American crayfish species as hosts for the crayfish plague pathogen Aphanomyces astaci contribute to the decline of native European crayfish populations. At least six American crayfish species have been reported in the Netherlands but the presence of this pathogenic oomycete with substantial conservational impact has not yet been confirmed in the country. We evaluated A. astaci prevalence in Dutch populations of six alien crustaceans using species-specific quantitative PCR. These included three confirmed crayfish carriers (Orconectes limosus, Pacifastacus leniusculus, Procambarus clarkii), two recently introduced but yet unstudied crayfish (Orconectes cf. virilis, Procambarus cf. acutus), and a catadromous crab Eriocheir sinensis. Moderate levels of infection were observed in some populations of O. limosus and P. leniusculus. Positive results were also obtained for E. sinensis and two Dutch populations of O. cf. virilis. English population of the latter species was also found infected, confirming this taxon as another A. astaci carrier in European waters. In contrast, Dutch P. clarkii seem only sporadically infected, and the pathogen was not yet detected in P. cf. acutus. Our study is the first confirmation of crayfish plague infections in the Netherlands and demonstrates substantial variation in A. astaci prevalence among potential hosts within a single region, a pattern possibly linked to their introduction history and coexistence.
Coxiella burnetii Seroprevalence in Small Ruminants in The Gambia
Klaassen, M. ; Roest, Hendrik-Jan ; Hoek, W. van der; Goossens, B. ; Secka, A. ; Stegeman, A. - \ 2014
PLoS ONE 9 (2014)1. - ISSN 1932-6203
hospitalized febrile patients - q-fever - domestic ruminants - northern tanzania - goats - netherlands - prevalence - antibodies - diagnosis - children
Q fever is a zoonosis caused by Coxiella burnetii, a Gram negative bacterium present worldwide. Small ruminants are considered the main reservoirs for infection of humans. This study aimed to estimate the extent of C. burnetii infection among sheep and goats in part of The Gambia.
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