Classical swine fever in wild boar: surveillance strategies under the microscope

Objective: Classical Swine Fever (CSF) is a highly contagious viral disease, which affects all suid species. CSF infection in wild boar can play an important role in disease introduction to commercial pig holdings. Due to its high economic impact, efficient but also cost-effective surveillance strategies have to be implemented not only in commercial pig holdings but also in wild boar. In Germany, the last CSF outbreak occurred in wild boar in 2009. Consequently, vaccination had been implemented until 2012. Since June 2012, Germany is considered to be free from CSF. Following this, active surveillance in wild boar has been carried out according to the directives of the European Union (Council directive 2001/89/EC). Germany's implementation of these regulations plan to take 59 samples per district per year to be capable to demonstrate freedom from disease on district level (conventional method). Compared to conventional surveillance, risk-based surveillance approaches may achieve similar performance at lower cost or better performance at the same cost. Within the framework of the European project RISKSUR (http://www.fp7-risksur.eu/) we conducted a simulation study to compare the performances of different surveillance approaches for CSF in an unvaccinated wild boar population in an area free from the disease. The aim of the study was to find out whether surveillance with the objective of demonstrating freedom from disease in wild boar could be designed more effectively using risk-based or alternative methods compared to using conventional methods. Methods: For the simulation model, R (www.r-project.org) was used for statistical computing and displaying graphs. A virtual wild boar population was generated and an infection initiated within this population. As study area we used the federal state of Rhineland Palatinate. The population size estimates for the considered region, determined using fecal DNA samples, were used to calculate the total number of wild boar within the simulation study. To assure a general pattern of the population structure we chose districts from three areas with different epidemiological situations. The simulated population was structured containing information on age, gender and the type of carcass (shot healthy, shot sick, injured through road traffic accident and found dead). The setup of the infection was done on the basis of data from Mecklenburg-Western Pomerania to estimate the increase of the seroprevalence at the beginning of an infection. The risk factor analysis used to define the risk-based surveillance approaches was done through literature search, expert opinion and bivariate analysis of infection data. Due to a lack of appropriate information in Rhineland Palatinate, infection data of the federal state of Mecklenburg-Western Pomerania were used as data basis as well. The simulation was conducted on the basis of real hunting data of Rhineland Palatinate and the surveillance approach, performed following the regulations of the European Union was simulated With these simulations, the probability of case detection and the time until the first case detection were determined and used as reference values. These values were then compared to the values resulting from the simulation of different alternative and risk-based surveillance methods. Alternative surveillance methods were increased sampling in the age class at higher risk of infection or in the season with an assumed higher detection probability. Furthermore we simulated the sampling in dependence of the population density in the different districts in two different ways. One approach was to sample only in districts were the population density was above a predefined threshold, whereas the other approach was to determine the sample size in the individual districts in dependence of the population density. Results: The results of the fecal DNA analyses showed an estimated mean of 2,593 wild boar per district with a maximum of 8,524 and a minimum of 30 wild boar (median: 2,163). The real hunting data collected in specified districts (27 districts) of Rhineland Palatinate between 2003 and 2014 constituted the basis for the age and sex structure of the simulated population. In total we had 105,439 records. In the analyzed data the sex proportion of shot male and female animals was almost equal (male: 52.4%; female: 47.6%). The age distribution showed that the number of shot animals aged less than one year were highest (55.1%) and the number of samples coming from animals over 2 years was lowest (10.8%). Almost all samples (99.6%) were collected from hunted healthy animals, i.e. from active surveillance. Most samples were taken in the months of November (15.92%), December (13.68%) and January (12.57%). For the simulation of hunting, averaged values of the hunting bag data from 2003-2011 were used. In average 1,340 wild boar/district/year were hunted (min: 0; max: 4,573; median: 1,113). For the setup of the infection into the simulated population, data from Mecklenburg-Western Pomerania were used. They consisted of 17,492 data sets resulting from the years 1993 and 1994, which were collected in six non-vaccination districts. Within this dataset, 2,652 samples had tested seropositive for CSF. Due to the low number of positive cases identified through serological and virological testing in the data set of Rhineland-Palatinate, surveillance data from non-vaccination districts within Mecklenburg-Western Pomerania were used for risk analysis. The data consisted of 85,105 data sets from 1994-2000. The sex, age and carcass distribution showed a similar pattern as the data from Rhineland-Palatinate. Bivariate analysis showed that age plays a role in the probability of being serologically or virologically positive. These findings were supported by the findings of the literature search as well as by expert opinion. In the literature, it was found that the probability of samples gathered through passive surveillance being positive is assumed to be higher. However, the low number of available passive surveillance data made it impossible to support this assumption through statistical analysis. Additionally, experts suggest that seasonality of the hunting and infection as well as population density may be considered as risk factors for infection. The following initial results refer to simulations in a defined area of Rhineland Palatinate consisting of three neighboring districts. From 1000 simulation repetitions of sampling 59 samples per district over the year, by serological examination the infection was detected 1000 times per district (reference value for detection probability). On average 331 cases were detected in the first month of infection (reference value for time until first case is detected). By serological investigations of 59 animals aged less than 1 year infection was not detected at all in 11 simulation runs. On average 162 cases were detected within the first month. However, investigating 59 animals aged over 2 years serologically, the infection was detected 1000 times and 688 times already in the first month of infection. Conclusion: The first results of the simulation model indicate that alternative surveillance strategies show a similar probability of detection. However, serological surveillance of animals aged over two years reduced the time until the first case was detected significantly. Additionally, it might be assumed that through changes in sampling strategies e.g. based on population density thresholds, a reduction of costs is possible. The resulting financial resources could be used to increase sampling following the risk based approaches, therefore increasing the detection probability. They could also be used for campaigns supporting for example passive surveillance. However, the effectiveness of the single surveillance approaches should not only be measured by the outputs of the model, but also through a comprehensive evaluation of the whole surveillance system, including acceptability and practicability of the system. Moreover, the surveillance could be designed taking different risk factors into account and could therefore have the potential to result in a better performance. If higher numbers of animals found dead were investigated, passive surveillance would be an alternative. However, also in the future it will be difficult to reach higher numbers of samples from passive surveillance. Finally it has to be mentioned that due to the limitation of getting accurate population abundance data in wild life, designing surveillance schemes and the establishment of effective surveillance strategies will always constitute a certain challenge. (Résumé d'auteur

Bullous pemphigoid in infants: characteristics, diagnosis and treatment

BACKGROUND: Bullous pemphigoid (BP) in infants is a rare but increasingly reported autoimmune blistering skin disease. Autoantibody reactivity is usually poorly characterized. Current guidelines do not address specific aspects of the infantile form of BP. The objectives of this study are to define clinical and diagnostic characteristics of infantile BP and develop a treatment algorithm. METHODS: Detailed characterization of a current case series of five infants with BP from our departments. Comprehensive analysis of all reported cases (1-12 months) with respect to clinical and laboratory characteristics, treatment and outcome. RESULTS: In total 81 cases were identified (including our own). The mean age was 4.5 months. Moderately severe and severe disease was seen in 84% of cases. Involvement of hands and feet was present in all cases. Immunofluorescence microscopy was comparable with BP in adults. Where analyzed, the NC16A domain of bullous pemphigoid 180 kDa antigen/collagen XVII (BP180) was identified as the major target antigen. BP180 NC16A ELISA values in our cohort were significantly higher than in a control cohort of 28 newly diagnosed adult patients. 50% of patients were treated with systemic corticosteroids, 20% with a combination of systemic corticosteroids and dapsone or sulfapyridine and 10% with topical corticosteroids alone. 14% of patients needed a combination of multiple immunosuppressants. All but one patient reached remission. Relapses were rare. CONCLUSIONS: Presentation of infantile BP is often severe with blistering of hands and feet present in all cases. Pathogenesis and diagnostic criteria are comparable to adult BP, yet BP180 NC16A ELISA levels seem to be significantly higher in infants. The overall disease outcome is favorable. Based on the results of this study we propose a treatment algorithm for infantile BP

Factors associated with grower herd performance in three New Zealand pig farms

The aim of this observational study was to identify performance parameters, which can be used to predict market weight of a batch of pigs on commercial farms. For that purpose, we obtained weekly retro- and prospective production records from three New Zealand pig farms. The observation periods on farms A, B, and C were 140, 127 and 90 weeks, respectively. As we expected the data to be autocorrelated, we used two modelling approaches for multivariable analysis: An autoregressive (AR) model and an ordinary least squares (OLS) regression model (‘naive approach’). Analyses were performed separately for each farm. Using an AR-model, we identified four production parameters (weaning age, two sample weights and days to market) across the three farms that were effective in predicting market weight with accuracies greater than 70%. All AR-models yielded stationary and normally distributed residuals. In contrast, residuals of the OLS-models showed remaining autocorrelation on farms B and C indicating biased model estimates. Using an AR-model also has the advantage that immediate future observations can be forecasted. This is particularly useful as all predictor variables (apart from ‘Days to market’) could be obtained a month prior to marketing on all farms.Die Zielsetzung dieser Beobachtungsstudie war es, Leistungsparameter zu identifizieren, die es ermöglichen das Vermarktungsgewicht von Schweinegruppen auf kommerziellen Schweinefarmen vorherzusagen. Für diesen Zweck haben wir sowohl retro- als auch prospektive Produktionsdaten von drei neuseeländischen Schweinefarmen erhoben. Die Beobachtungszeiträume auf den Farmen A, B und C erstreckten sich über 140, 127 und 90 Wochen. Da wir Autokorrelation in den Daten vermuteten, benutzten wir zwei Modellierungsansätze: Ein autoregressives (AR) Model und ein Ordinary Least Squares (OLS) Regressionsmodel (‚naives Model’). Wir entwickelten ein separates Model für jede einzelne Farm. Mit Hilfe des AR-Models konnten wir vier Produktionsparameter (‚Absetzalter’, zwei Gewichtsmessungen und ‚Tage bis zur Schlachtung’) identifizieren, die das Schlachtgewicht auf allen drei Farmen mit mehr als 70% Genauigkeit vorhersagen. Alle AR-Modelle produzierten stationäre und normalverteilte Residuen. Im Gegensatz dazu, Residuen der OLS-Modelle zeigten verbleibende Autokorrelation für die Farmen B und C, was auf verfälschte Modelschätzungen schliessen lässt. Die Anwendung eines AR-Models hat zudem den Vorteil dass unmittelbar zukünftige Beobachtungen vorhergesagt werden können. Dies ist vor allem hilfreich da alle unabhängigen Variablen (abgesehen von ‚Tage bis zur Schlachtung’) auf jeder Farm ein Monat vor der Schlachtung erhoben werden können

Interaction of Vibrio cholerae non-O1/non-O139 with Copepods, Cladocerans and Competing Bacteria in the Large Alkaline Lake Neusiedler See, Austria

Vibrio cholerae is a human pathogen and natural inhabitant of aquatic environments. Serogroups O1/O139 have been associated with epidemic cholera, while non-O1/non-O139 serogroups usually cause human disease other than classical cholera. V. cholerae non-O1/non-O139 from the Neusiedler See, a large Central European lake, have caused ear and wound infections, including one case of fatal septicaemia. Recent investigations demonstrated rapid planktonic growth of V. cholerae non-O1/non-O139 and correlation with zooplankton biomass. The aim of this study was to elucidate the interaction of autochthonous V. cholerae with two dominant crustacean zooplankton species in the lake and investigate the influence of the natural bacterial community on this interaction. An existing data set was evaluated for statistical relationships between zooplankton species and V. cholerae and co-culture experiments were performed in the laboratory. A new fluorescence in situ hybridisation protocol was applied for quantification of V. cholerae non-O1/non-O139 cells, which significantly reduced analysis time. The experiments clearly demonstrated a significant relationship of autochthonous V. cholerae non-O1/non-O139 with cladocerans by promoting growth of V. cholerae non-O1/non-O139 in the water and on the surfaces of the cladocerans. In contrast, copepods had a negative effect on the growth of V. cholerae non-O1/non-O139 via competing bacteria from their surfaces. Thus, beside other known factors, biofilm formation by V. cholerae on crustacean zooplankton appears to be zooplankton taxon specific and may be controlled by the natural bacterial community. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00248-010-9764-9) contains supplementary material, which is available to authorized users

Comparison of different diagnostic protocols for the detection of Toxocara spp. in faecal samples of cats and dogs

Background Toxocara canis and Toxocara cati are parasitic nematodes that occur worldwide. As embryonated Toxocara spp. eggs in the environment pose a zoonotic risk, especially for children, optimal diagnostic approaches are necessary for effective disease response and management, including surveillance. However, little is known about the performance of different diagnostic protocols for detecting Toxocara spp. in the faeces of cats and dogs, hampering movement towards an optimal diagnostic process. This study aimed to compare detection methods, including a newly developed sequential sieving protocol (SF-SSV) and a high-throughput multiplex qPCR-based method to facilitate epidemiological studies. Methods Species-specific Toxocara spp. egg suspensions and canine and feline faecal samples from the field were used to estimate analytical and diagnostic sensitivity of the protocols. The performance of two automated DNA extraction protocols using enzymatic and mechanical lysis were compared by multiplex qPCR, targeting both T. canis and T. cati-specific genomic sequences. All samples were examined by microscopy-based techniques, the sedimentation flotation technique (SF) and a newly developed SF-SSV for the detection, enrichment and purification of parasite eggs. The costs and processing times necessary for all protocols were estimated and compared for both single samples and sets of 100 samples. Results To detect Toxocara spp. eggs, SF-SSV showed the highest analytical sensitivity and a significantly higher diagnostic sensitivity than the DNA detection methods. Mechanical lysis performed better than enzymatic lysis for automated DNA extraction. In automated DNA extraction, 96-well plates performed better than 24-well plates. DNA detection and microscopy-based parasitological methods showed substantial agreement between the results generated by each method. Microscopy-based techniques required the lowest costs and least hands-on time for a single sample. However, when costs and labour were estimated for a set of 100 samples, the DNA detection protocol using 96-well plates for extraction revealed costs similar to SF-SSV and the fastest processing times. Conclusions SF-SSV was superior in terms of analytical and diagnostic sensitivity for the detection of Toxocara spp. eggs. For larger sets of samples, multiplex qPCR-based DNA detection represents an alternative to microscopy-based methods, based on the possibility of faster sample processing at similar costs to SF-SSV, and the ability to provide species-specific diagnoses

Guidance for evaluating integrated surveillance of antimicrobial use and resistance

Antimicrobial resistance (AMR) resulting from antimicrobial use (AMU) is an emerging threat to global health. One of the key elements for a better understanding and management of AMU and AMR is to develop effective and efficient integrated surveillance systems that consider the complex epidemiology of these issues and the impacts of resistance on humans, animals and the environment. Consequently, for this project, an international consortium of experts from multiple fields called CoEvalAMR was formed with the objectives to study user needs, characterise and compare existing tools for the evaluation of integrated AMU and AMR surveillance, apply them to case studies, and elaborate guidance on the purpose-fit selection and the use of the tools. For the comparison of evaluation tools, questions were extracted from existing tools and attributed to themes, to assess the user needs, interviews were conducted with national key stakeholders, and we applied a series of different evaluation tools to understand and document their strengths and weaknesses. The guidance was refined iteratively. From 12 evaluation tools, 1117 questions/indicators were extracted and attributed to seven emerging themes. Twenty-three experts were interviewed, who suggested to increase the ease-of-use, grant open access, provide web-based interfaces and allow results to be automatically generated. Respondents also wished for tools providing the flexibility to conduct a rapid review, or an in-depth analysis of the surveillance system, depending on the evaluation objectives. The case studies emphasised that proper evaluations require adequate resources, typically requiring the involvement of several assessors and/or stakeholders, and can take weeks or months to complete. The resulting web-based guidance comprises six main sections: 1. Introduction to surveillance evaluation, 2. Evaluation of surveillance for AMU and AMR, 3. Evaluation tools, 4. Support for selecting an evaluation tool, 5. Case studies and 6. Directory of existing tools. The audience for the guidance is personnel working in public, private, and non-governmental organisations, from public health, animal health, plant health and environmental health, at local, national and international levels. We conclude that the field is challenged by opposing user needs for reduction and simplicity versus system approaches allowing the synthesis of that knowledge to sufficiently reflect the complexity of AMU and AMR ecology for real-world decisions. The CoEvalAMR web platform allows a better understanding of the different evaluation tools and assists users in the selection of an approach that corresponds to their evaluation needs. The CoEvalAMR consortium continues to address remaining gaps and consolidate evaluation tools and approaches in the future

Ewing sarcoma: Diagnostic and therapeutic options : a comparison of current imaging techniques for the diagnosis of Ewing sarcoma

Thema Ewing-Sarkom: Diagnose- und Therapiemöglichkeiten - Ein Vergleich der gängigen bildgebenden Verfahren für die Diagnose des Ewing-Sarkoms Problem Das Ewing-Sarkom ist der zweithäufigste maligne Knochentumor des Kindes- und Jugendalters. Bei einer kleinen Zahl von Patientinnen und Patienten (etwa 5%), wird ein reines Weichteil-Ewing-Sarkom diagnostiziert. Besonders wichtig ist eine rechtzeitige Diagnose. 20-30% der Patientinnen und Patienten weisen bei Diagnosestellung bereits Fernmetastasen auf, meist in der Lunge und/oder im Skelettsystem. Ohne systemische Behandlung entwickeln über 80% der Patientinnen und Patienten Fernmetastasen. In der vorliegenden Arbeit werden die verschiedenen bildgebenden Diagnoseverfahren (Röntgen, CT, MRT, PET, PET-CT, Szintigraphie) des Ewing-Sarkoms verglichen. Fragestellung Welchen Stellenwert haben bildgebende Verfahren bei der Diagnose von Ewing-Sarkomen? Methode Zur Verfassung dieser Bachelorarbeit wurde eine qualitative retrospektive Analyse der Datenlage in Literaturdatenbanken wie GOOGLE SCHOLAR oder PUBMED im Zeitraum von Oktober bis Dezember 2020 durchgeführt. Ergebnisse Ab einer bestimmten Tumorgröße sind allen gängigen bildgebenden Verfahren in der Lage ein Ewing-Sarkom zu detektieren. Die Diagnosestellung mittels Röntgenaufnahmen ist der Computertomographie besonders im Bereich von sehr kleinen Veränderungen des Knochens in Bezug auf die Dichte und der Struktur des Knochens unterlegen. Intraossär gelegene Ewing-Sarkome können mit einer CT-Untersuchung sehr gut erkannt werden. Ein großer Nachteil von Computertomographien ist die hohe Strahlenbelastung besonders für Kinder und Jugendliche, auch bei Verwendung von low-dose-CT-Protokollen. Ewing-Sarkome in Weichteilgewebe sind im CT schlecht diagnostizierbar. Hier ist die MRT bzw. die Ganzkörper-MRT die überlegene Untersuchungsmethode. Bei der Detektion von Metastasen erwiesen sich die FDG-PET-Untersuchung und die PET/CT-Untersuchung als besonders sensitiv und erkannten Metastasen frühzeitig. Hybridtechniken wie das PET/CT sind einer PET-Untersuchung in Bezug auf die Sensitivität, der Spezifität und der Genauigkeit überlegen. Diskussion Alle gängigen bildgebenden Verfahren können ab einer gewissen Tumorgröße ein Ewing-Sarkom erkennen. Bei Kinder und Jugendlichen muss bei der Auswahl des Verfahrens besonders auf die Strahlenbelastung geachtet werden. Der Nutzen und das Risiko jeder radiologischen Untersuchung sind abzuwägen. Die Aufgabe einer/eines Radiologietechnologin/-technologen ist es, auf bildgebende Verfahren hinzuweisen, welche sensitiver oder spezifischer als andere Verfahren sind. Neue schonendere Untersuchungsverfahren oder -protokolle sind zu bevorzugen. Schlussfolgerung Je nach Fragestellung und Anforderung an ein bildgebendes Verfahren zur Detektion eines Ewing-Sarkoms hat jedes Verfahren charakteristische Vor- und Nachteile. Zumeist wird eine Kombination mehrerer Techniken angewendet um die Diagnose abzusichern bzw. andere Erkrankungen auszuschließen.Subject Ewing sarcoma: Diagnostic and therapeutic options - A comparison of current imaging techniques for the diagnosis of Ewing sarcoma Problem Ewing's sarcoma is the second most common malignant bone tumor of childhood and adolescence. A small number of patients (about 5%) are diagnosed with pure soft tissue Ewing sarcoma. Timely diagnosis is particularly important. 20-30% of patients already have distant metastases at diagnosis, mostly in the lungs and/or skeletal system. Without systemic treatment, over 80% of patients develop distant metastases. In the present study, the different imaging diagnostic procedures (X-ray, CT, MRI, PET, PET-CT, scintigraphy) for Ewing sarcoma are compared. Research Question What is the significance of imaging techniques in the diagnosis of Ewing sarcoma? Method For the preparation of this bachelor thesis, a qualitative retrospective analysis of the data available in literature databases such as GOOGLE SCHOLAR or PUBMED was performed in the period from October to December 2020. Results From a certain tumor size on, all common imaging techniques are able to detect Ewing sarcoma. Diagnosis by means of X-rays is inferior to computed tomography, especially in the area of very small changes in the density and structure of the bone. Intraosseous Ewing sarcomas can be detected very well with a CT examination. A major disadvantage of computed tomography is the high radiation exposure, especially for children and adolescents, even when using low-dose CT protocols. Ewing sarcomas in soft tissue are difficult to diagnose on CT. Here, MRI or whole-body MRI is the superior examination method. For the detection of metastases, the FDG-PET examination and the PET/CT examination proved to be particularly sensitive and detected metastases at an early stage. Hybrid techniques such as PET/CT are superior to PET examination in terms of sensitivity, specificity and accuracy. Discussion All current imaging techniques can detect Ewing sarcoma from a certain tumor size onwards. In children and adolescents, special attention must be paid to radiation exposure when selecting the procedure. The benefits and risks of each radiological examination must be weighed up. It is the task of a radiological technologist to point out imaging procedures that are more sensitive or specific than other procedures. New, gentler examination procedures or protocols are to be preferred. Conclusion Depending on the problem and the requirements for an imaging procedure for the detection of Ewing sarcoma, each procedure has characteristic advantages and disadvantages. In most cases, a combination of several techniques is used to confirm the diagnosis or exclude other diseases.Birgit SchauerBachelorarbeit Graz, Fachhochschule Joanneum 202

Evaluation of sources of error in weight records of commercially raised growing pigs : a thesis presented in partial fulfillment of the requirements for the degree of Master of Veterinary Studies in Epidemiology at Massey University, Palmerston North, New Zealand

The objective of this research was to investigate sources of errors in pig weight measurements. Three studies were conducted using data from one commercial New Zealand pig farm. In XChapter 4X, finisher pigs fed ad libitum or via a computerized liquid feeding system were weighed four times a day over a fourday period. Results showed that standardization of weighing time reduced diurnal fluctuations in pig weight. However, multivariate analysis showed that there was a significant interaction between day and time of day, which indicates that diurnal fluctuations in live weight are not consistent between days, particularly in ad libitum fed pigs. Hence, XChapter 5X investigated whether overnight feed withdrawal for 11 hours (weaners) or 17 hours (growers and finishers) is effective in reducing between-pig variation in live weight and growth rate. For grower and finisher pigs, feed withdrawal was associated with a reduction in variability in live weight and growth rate by up to 11.5%, whilst the effect was inconsistent in weaner pigs. It is recommended to repeat the investigation on other farms to assess long-term effects on pig performance before general recommendations can be made. XChapter 6X compared the magnitude of sampling error when sampling pens from batches of pigs, using different sample sizes and sampling methods. Increasing the portion of randomly selected pens reduced the sampling error, but in a diminishing manner. Purposive selection of two pens reduced sampling error by more than 64% compared with random sampling. However, purposive sampling introduces the risk of obtaining biased estimates. Thus, it is recommended to select pens from batches at random. These results may be used as an educational tool to demonstrate how to minimize errors in pig weights. Collecting more accurate weight records is likely to lead to improved interpretability of pig weights, and may promote better use of production data