Flying-Fox Species Density-A Spatial Risk Factor for Hendra Virus Infection in Horses in Eastern Australia

Hendra virus causes sporadic but typically fatal infection in horses and humans in eastern Australia. Fruit-bats of the genus Pteropus (commonly known as flying-foxes) are the natural host of the virus, and the putative source of infection in horses; infected horses are the source of human infection. Effective treatment is lacking in both horses and humans, and notwithstanding the recent availability of a vaccine for horses, exposure risk mitigation remains an important infection control strategy. This study sought to inform risk mitigation by identifying spatial and environmental risk factors for equine infection using multiple analytical approaches to investigate the relationship between plausible variables and reported Hendra virus infection in horses. Spatial autocorrelation (Global Moran’s I) showed significant clustering of equine cases at a distance of 40 km, a distance consistent with the foraging ‘footprint’ of a flying-fox roost, suggesting the latter as a biologically plausible basis for the clustering. Getis-Ord Gi* analysis identified multiple equine infection hot spots along the eastern Australia coast from far north Queensland to central New South Wales, with the largest extending for nearly 300 km from southern Queensland to northern New South Wales. Geographically weighted regression (GWR) showed the density of P. alecto and P. conspicillatus to have the strongest positive correlation with equine case locations, suggesting these species are more likely a source of infection of Hendra virus for horses than P. poliocephalus or P. scapulatus. The density of horses, climate variables and vegetation variables were not found to be a significant risk factors, but the residuals from the GWR suggest that additional unidentified risk factors exist at the property level. Further investigations and comparisons between case and control properties are needed to identify these local risk factors

Flying-Fox Species Density-A Spatial Risk Factor for Hendra Virus Infection in Horses in Eastern Australia

Hendra virus causes sporadic but typically fatal infection in horses and humans in eastern Australia. Fruit-bats of the genus Pteropus (commonly known as flying-foxes) are the natural host of the virus, and the putative source of infection in horses; infected horses are the source of human infection. Effective treatment is lacking in both horses and humans, and notwithstanding the recent availability of a vaccine for horses, exposure risk mitigation remains an important infection control strategy. This study sought to inform risk mitigation by identifying spatial and environmental risk factors for equine infection using multiple analytical approaches to investigate the relationship between plausible variables and reported Hendra virus infection in horses. Spatial autocorrelation (Global Moran’s I) showed significant clustering of equine cases at a distance of 40 km, a distance consistent with the foraging ‘footprint’ of a flying-fox roost, suggesting the latter as a biologically plausible basis for the clustering. Getis-Ord Gi* analysis identified multiple equine infection hot spots along the eastern Australia coast from far north Queensland to central New South Wales, with the largest extending for nearly 300 km from southern Queensland to northern New South Wales. Geographically weighted regression (GWR) showed the density of P. alecto and P. conspicillatus to have the strongest positive correlation with equine case locations, suggesting these species are more likely a source of infection of Hendra virus for horses than P. poliocephalus or P. scapulatus. The density of horses, climate variables and vegetation variables were not found to be a significant risk factors, but the residuals from the GWR suggest that additional unidentified risk factors exist at the property level. Further investigations and comparisons between case and control properties are needed to identify these local risk factors

Hendra Virus and Horse Owners – Risk Perception and Management

Hendra virus is a highly pathogenic novel paramyxovirus causing sporadic fatal infection in horses and humans in Australia. Species of fruit-bats (genus Pteropus), commonly known as flying-foxes, are the natural host of the virus. We undertook a survey of horse owners in the states of Queensland and New South Wales, Australia to assess the level of adoption of recommended risk management strategies and to identify impediments to adoption. Survey questionnaires were completed by 1431 respondents from the target states, and from a spectrum of industry sectors. Hendra virus knowledge varied with sector, but was generally limited, with only 13% of respondents rating their level of knowledge as high or very high. The majority of respondents (63%) had seen their state’s Hendra virus information for horse owners, and a similar proportion found the information useful. Fifty-six percent of respondents thought it moderately, very or extremely likely that a Hendra virus case could occur in their area, yet only 37% said they would consider Hendra virus if their horse was sick. Only 13% of respondents stabled their horses overnight, although another 24% said it would be easy or very easy to do so, but hadn’t done so. Only 13% and 15% of respondents respectively had horse feed bins and water points under solid cover. Responses varied significantly with state, likely reflecting different Hendra virus history. The survey identified inconsistent awareness and/or adoption of available knowledge, confusion in relation to Hendra virus risk perception, with both over-and under-estimation of true risk, and lag in the uptake of recommended risk minimisation strategies, even when these were readily implementable. However, we also identified frustration and potential alienation by horse owners who found the recommended strategies impractical, onerous and prohibitively expensive. The insights gained from this survey have broader application to other complex risk-management scenarios

Global-Local Finite Element Analysis

114 σ.Η αναλυτική επίλυση πολύπλοκων προβλημάτων της μηχανικής στις μέρες μας καθίσταται δυσχερής εως αδύνατη χωρίς την εφαρμογή αριθμητικών μεθόδων και τη χρήση ηλεκτρονικού υπολογιστή. Η μέθοδος των πεπερασμένων στοιχείων αποτελεί σήμερα ένα ισχυρό εργαλείο για την επίλυση τέτοιων προβλημάτων και εξελίσσεται με μεγάλη ταχύτητα τόσο σε ακαδημαϊκό όσο και σε επαγγελματικό επίπεδο. Ενδεικτικά, αν και επινοήθηκε και χρησιμοποιήθηκε για τη στατική ανάλυση φορέων, έχει καθολικότερη εφαρμογή σε μια ευρύτερη κατηγορία προβλημάτων του μηχανικού, όπως στη ρευστομηχανική, στη μεταφορά θερμότητας, στην ακουστική, στον ηλεκτρομαγνητισμό και στην εμβιομηχανική. Επιπλέον, η εξέλιξη στων Η/Υ με τις ολοένα μεγαλύτερες δυνατότητες διαχείρισης όγκου δεδομένων αλλά και με την αύξηση της ταχύτητας εκτέλεσης των αριθμητικών πράξεων κατέστησε εφικτή την επίλυση σύνθετων προβλημάτων τα οποία θεωρούνταν απροσπέλαστα πριν μερικά χρόνια. Στην κατηγορία αυτή, των προβλημάτων αυξημένου υπολογιστικού κόστους, ανήκει και η καταστατική περιγραφή πολυφασικών υλικών. Είναι γεγονός ότι το μεγαλύτερο μέρος των παραγώμενων δομικών υλικών σήμερα, παρουσιάζει κάποιο είδος ανομοιογένειας, διακριτή ή μη στην κλίμακα δομικών έργων. Χαρακτηριστικά παραδείγματα αποτελούν τα κράματα μετάλλων, τα πορώδη, τα πολυκρυσταλλικά και τα σύνθετα υλικά στα οποία το μέγεθος, το σχήμα και οι ιδιότητες των συστατικών τους μερών καθορίζουν άμεσα τη συνολική τους μηχανική συμπεριφορά. Διάφορες τεχνικές έχουν αναπτυχθεί για την προσομοίωση και την περιγραφή της απόκρισης ανομοιογενών υλικών. Η παρούσα εργασία επικεντρώνεται στη μέθοδο ομογενοποίησης πολλαπλών κλιμάκων η οποία συνίσταται στην επίλυση δύο εμφωλευμένων προβλημάτων συνοριακών τιμών, για τη μακροκλίμακα και τη μικροκλίμακα αντίστοιχα. Τα βασικά χαρακτηριστικά μιας τέτοιας μεθόδου είναι ότι - Δεν απαιτείται η περιγραφή των καταστατικών νόμων του μακροφορέα. - Παρέχει τη δυνατότητα ενσωμάτωσης μεγάλων παραμορφώσεων και στροφών τόσο στην προσομοίωση της μικροκλίμακας όσο και του μακροφορέα. - Παρέχει τη δυνατότητα λεπτομερούς προσομοίωσης των συστατικών μερών της μικροκλίμακας. - Επιτρέπει οποιαδήποτε τεχνική επίλυσης στην κλίμακα του μικροφορέα. Αναλυτικά, σύμφωνα με τη μέθοδο αυτή. υπολογίζεται το διάνυσμα ανηγμένων παραμορφώσεων σε κάθε υλικό σημείο του μακροφορέα το οποίο στη συνέχεια χρησιμοποιείται για τη μόρφωση των συνοριακών συνθηκών του αντιπροσωπευτικού μικροφορέα στο αντίστοιχο σημείο. Μετά την επίλυση του προβλήματος συνοριακών τιμών της μικροκλίμακας, το διάνυσμα των τάσεων του μακροφορέα υπολογίζεται μέσα από τη διαδικασία ομογενοποίησης του πεδίου των τάσεων και κατά τον τρόπο αυτό υπολογίζεται η σχέση τάσεων ανηγμένων παραμορφώσεων για κάθε υλικό σημείο Ωστόσο, υπάρχουν κάποιοι περιορισμοί στην εφαρμογή της εν λόγω υπολογιστικής τεχνικής. Συγκεκριμένα, παρά το ότι κατά την προσομοίωση λαμβάνονται υπ' όψην οι διάφορες παράμετροι της μικροκλίμακας όπως το ποσοστό όγκου, η κατανομή και η μορφολογία των συστατικών μερών του υλικού, τα αποτελέσματα της μεθόδου είναι ανεξάρτητα από το απόλυτο μέγεθος του αντιπροσωπευτικού όγκου της μικροκλίμακας. Παρ' όλα αυτά, η τεχνική ομογενοποίησης στα πλαίσια ανάλυσης πολλαπλών κλιμάκων αποτελεί ένα σημαντικό εργαλείο για τον υπολογισμό των καταστατικών σχέσεων πολυφασικών υλικών στα οποία είναι αδύνατη η εφαρμογή οποιασδήποτε άλλης μεθόδου.Nowadays, analysis of complicated problems in the domain of mechanics consti- tutes a hard and even impossible task without the implementation of numerical methods and the employment of computational machines. Finite element method is a powerful tool for the solution of such problems and is rapidly developed in an academic and professional sense. Even if it was developed and implemented for structural analysis, it is widely employed in several domains such as in fluid mechanics, heat transfer, acoustics and electromagnetism. Furthermore, the development of computer hardware in terms of data processing, has significantly contributed to the solution of problems that were considered inaccessible a few years ago. Most of the materials produced in industry are heterogeneous on one or another spatial scale. Typical examples include metal alloy systems, porous media and polycrystalline materials and composites. The overall response of these micro heterogeneous materials depends strongly on the size, shape properties and spatial distribution of the microstructural components. Several techniques have been developed for the prediction of the macroscopic behavior of such materials. The present work is concentrated on the first order homogenization technique in the framework of a multi-scale approach which consists of the solution of two nested boundary value problems, for the macro-scale and the micro-scale respectively. Methods of this type - Do not require any constitutive assumption with respect to the overall ma- terial behavior. - Enable the incorporation of large deformations and rotations on both micro and macrolevel. - Provide the possibility to introduce detailed microstructural information. - Allow the use of any modelling technique at the microlevel. Concretely, according to this approach, the macroscopic deformation tensor is calculated for every integration point of the macrostructure and then is used to formulate the kinematic boundary conditions for the associated microstructural representative volume element (RVE). After the solution of the microstructural boundary value problem, the macroscopic stress tensor is computed by averaging the resulting microstructural stress field over the volume of the RVE and as a result, we obtain the stress-strain relation at every macroscopic point. However, there is a major disadvantage of the existing first-order computational homogenization. More specifically, this technique can account for the volume fraction, distribution and morphology of the micro-components however, it cannot take into account the absolute size of the microstructure making it thus impossible to treat microstructural size effects. Nevertheless, computational homogenization provides a significant strategy to obtain micro-macro structure-property relations for materials for which the overall macroscopic response cannot be computed by any other method.Κωνσταντινος Ε. Τατση

Australian bat lyssavirus infection in two horses

In May 2013, the first cases of Australian bat lyssavirus infections in domestic animals were identified in Australia. Two horses (filly-H1 and gelding-H2) were infected with the Yellow-bellied sheathtail bat (YBST) variant of Australian bat lyssavirus (ABLV). The horses presented with neurological signs, pyrexia and progressing ataxia. Intra-cytoplasmic inclusion bodies (Negri bodies) were detected in some Purkinje neurons in haematoxylin and eosin (H&E) stained sections from the brain of one of the two infected horses (H2) by histological examination. A morphological diagnosis of sub-acute moderate non-suppurative, predominantly angiocentric, meningo-encephalomyelitis of viral aetiology was made. The presumptive diagnosis of ABLV infection was confirmed by the positive testing of the affected brain tissue from (H2) in a range of laboratory tests including fluorescent antibody test (FAT) and real-time PCR targeting the nucleocapsid (N) gene. Retrospective testing of the oral swab from (H1) in the real-time PCR also returned a positive result. The FAT and immunohistochemistry (IHC) revealed an abundance of ABLV antigen throughout the examined brain sections. ABLV was isolated from the brain (H2) and oral swab/saliva (H1) in the neuroblastoma cell line (MNA). Alignment of the genome sequence revealed a 97.7% identity with the YBST ABLV strain

Risk for Infection with Highly Pathogenic Influenza A Virus (H5N1) in Chickens, Hong Kong, 2002

Infection was spread to commercial poultry farms through retail marking of live birds

Modelling the spread and control of African swine fever in domestic and feral pigs

African swine fever (ASF) represents a significant threat to the Australian pork sector and the economy in general. Estimates of the economic damages from a large multi-state outbreak of ASF in Australia exceed $A2 billion. ASF outbreaks are widespread and increasing in number in Asia and Europe. Although ASF is not present in Australia, detections of ASF viral fragments in undeclared pork products intercepted at the Australian border and the recent spread of the disease to neighbouring Papua New Guinea demonstrate the significance of the threat. The AADIS model (Bradhurst et al., 2015), simulates the spread and control of contagious emergency animal diseases such as foot-and-mouth disease. The ability to evaluate different outbreak scenarios in time and space, and trial various control measures, assists the development of animal health policy. This project expanded the AADIS modelling framework to simulate the potential spread and control of ASF in Queensland domestic and feral pig populations. Of particular interest was the epidemiological interface between domestic and feral pigs and the potential role of ASF-infectious feral pig carcasses in transmission. The upgraded model will provide a useful decision support tool to assist with preparedness and planning for ASF outbreaks. The report provides a literature review on ASF, feral pigs in Australia, and ASF decision support tools. Case studies on the spread and control of ASF in domestic and feral pigs demonstrate the functionality of the new model. Queensland was selected as the test case study area due to the wide distribution and high numbers of feral pigs and the availability of local expertise and data from Biosecurity Queensland, Department of Agriculture and Fisheries, Australian Pork Limited and SunPork Group Pty Ltd. The model was parameterised from the literature review and expert opinion that incorporated local knowledge of Australian production systems and environmental conditions. Note that the model is only parameterised for Queensland and will be scaled up to a national model through Biosecurity Innovation Program project 182021

Modelling the spread and control of African swine fever in domestic and feral pigs

African swine fever (ASF) represents a significant threat to the Australian pork sector and the economy in general. Estimates of the economic damages from a large multi-state outbreak of ASF in Australia exceed $A2 billion. ASF outbreaks are widespread and increasing in number in Asia and Europe. Although ASF is not present in Australia, detections of ASF viral fragments in undeclared pork products intercepted at the Australian border and the recent spread of the disease to neighbouring Papua New Guinea demonstrate the significance of the threat. The AADIS model (Bradhurst et al., 2015), simulates the spread and control of contagious emergency animal diseases such as foot-and-mouth disease. The ability to evaluate different outbreak scenarios in time and space, and trial various control measures, assists the development of animal health policy. This project expanded the AADIS modelling framework to simulate the potential spread and control of ASF in Queensland domestic and feral pig populations. Of particular interest was the epidemiological interface between domestic and feral pigs and the potential role of ASF-infectious feral pig carcasses in transmission. The upgraded model will provide a useful decision support tool to assist with preparedness and planning for ASF outbreaks. The report provides a literature review on ASF, feral pigs in Australia, and ASF decision support tools. Case studies on the spread and control of ASF in domestic and feral pigs demonstrate the functionality of the new model. Queensland was selected as the test case study area due to the wide distribution and high numbers of feral pigs and the availability of local expertise and data from Biosecurity Queensland, Department of Agriculture and Fisheries, Australian Pork Limited and SunPork Group Pty Ltd. The model was parameterised from the literature review and expert opinion that incorporated local knowledge of Australian production systems and environmental conditions. Note that the model is only parameterised for Queensland and will be scaled up to a national model through Biosecurity Innovation Program project 182021

A multi-jurisdictional outbreak of Salmonella Typhimurium infections linked to backyard poultry—Australia, 2020

Zoonotic salmonellosis can occur either through direct contact with an infected animal or through indirect contact, such as exposure to an infected animal's contaminated environment. Between May and August 2020, a multi-jurisdictional outbreak of Salmonella Typhimurium (STm) infection due to zoonotic transmission was investigated in Australia. In total, 38 outbreak cases of STm with a median age of 5 years were reported. Epidemiological investigation showed contact with live poultry to be a common risk factor with most cases recently purchasing one-week old chicks from produce/pet stores. Traceback investigation of cases identified 25 product/pet stores of which 18 were linked to a single poultry breeder farm. On farm environmental sampling identified the same STm genotype as identified in cases. Whole genome sequencing of both environmental and human outbreak isolates found them to be highly related by phylogenetic analysis. This investigation describes the first documented widespread zoonotic salmonellosis outbreak in Australia attributed to backyard poultry exposure and identified potential risk factors and prevention and control measures for future outbreaks. Prevention of future outbreaks will require an integrated One Health approach involving the poultry industry, produce/pet store owners, animal healthcare providers, public health and veterinary health agencies and the public

Hendra Virus Outbreak with Novel Clinical Features, Australia

To determine the epidemiologic and clinical features of a 2008 outbreak of Hendra virus infection in a veterinary clinic in Australia, we investigated the equine case-series. Four of 5 infected horses died, as did 1 of 2 infected staff members. Clinical manifestation in horses was predominantly neurologic. Preclinical transmission appears likely