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Mutze G.,Australian Department of Primary Industries and Fisheries | Kovaliski J.,Australian Department of Primary Industries and Fisheries | Butler K.,Australian Department of Primary Industries and Fisheries | Capucci L.,Istituto Zooprofilattico Sperimentale della Lombardia e dellEmilia | And 2 more authors.
Journal of Applied Ecology | Year: 2010

1. The effect of rabbit population density on transmission of rabbit haemorrhagic disease virus (RHDV) is a critical aspect of disease ecology for rabbit control and rabbit conservation. We examined the interaction between rabbit control and spread of RHDV and a non-pathogenic calicivirus (bCV) in Australian wild rabbit populations, and reviewed existing recommendations for control in this context.2. Rabbits were sampled at eight pairs of sites; from rabbit populations where densities had been reduced by conventional control and from matching uncontrolled populations. Sites chosen ranged from hot, arid areas where RHDV had greatly reduced rabbit numbers to cooler, higher-rainfall areas where rabbits remained more abundant. Virus activity was implied from antibody profiles in sera of surviving rabbits.3. Reducing population density by conventional control had a similar effect on disease transmission despite a seven-fold difference in initial density. Populations reduced by 70% or more had lower RHDV antibody prevalence in juvenile rabbits but not in adult rabbits, indicating that reducing rabbit density slowed but did not stop RHDV transmission. We found no interactions between rabbit control, RHDV and bCV that could be exploited to improve rabbit management.4. Synthesis and applications. Delayed RHDV infection in rabbit control sites is likely to be offset by higher mortality in older rabbits, so that conventional rabbit control does not reduce the impact of RHDV on rabbit populations. Only minor changes to delay the timing of summer rabbit control programmes in cooler areas of Australia are necessary to take best advantage of RHDV-induced reduction in rabbit numbers. For conservation management of rabbits in Europe, these findings indicate that RHDV may continue to have a severe impact on rabbit populations that have been reduced to low population density, but also raise the possibility that bCVs might be introduced to rabbit populations to aid their recovery. © 2010 The Authors. Journal compilation © 2010 British Ecological Society. Source

Mutze G.J.,Australian Department of Primary Industries and Fisheries | Sinclair R.G.,Australian Department of Primary Industries and Fisheries | Peacock D.E.,Australian Department of Primary Industries and Fisheries | Capucci L.,Istituto Zooprofilattico Sperimentale della Lombardia e dellEmilia | Kovaliski J.,Australian Department of Primary Industries and Fisheries
European Journal of Wildlife Research | Year: 2014

The frequency and timing of rabbit haemorrhagic disease (RHD) epizootics and their impact on different age groups of rabbits were studied for 15 years in a recovering rabbit population in South Australia. We recorded the number and body size of rabbits dying during RHD epizootics, collected tissue for genetic analysis of rabbit haemorrhagic disease virus variants and compared the number of carcasses found to the number of susceptible rabbits present at the beginning of each epizootic. All RHD epizootics occurred between late winter and spring, but, progressively, epizootics started earlier and became more frequent and prolonged, fewer susceptible adult rabbits were present during epizootics, and the age of rabbits dying of RHD declined. Increased infection and virus shedding in juvenile rabbits offers the most plausible explanation for those epidemiological changes; the disease is now increasingly transmitted through populations of kittens, starting before young-of-the-year reach adult size and persisting late in the breeding season, so that most rabbits are challenged in their year of birth. These changes have increased juvenile mortality due to RHD but reduced total mortality across all age groups, because age-specific mortality rates are lower in young rabbits than in older rabbits. We hypothesise that this may be the proximate cause of recovery in rabbit populations across Australia and possibly elsewhere. © 2014 Springer-Verlag Berlin Heidelberg. Source

Mutze G.,Australian Department of Primary Industries and Fisheries | Bird P.,Australian Department of Primary Industries and Fisheries | Jennings S.,Water and Natural ResourcesSA | Peacock D.,Australian Department of Primary Industries and Fisheries | And 4 more authors.
Wildlife Research | Year: 2014

Context Recovery of Australian rabbit populations from the impact of rabbit haemorrhagic disease virus (RHDV) contrasts with more prolonged suppression of wild rabbits in Europe, and has been widely discussed in the scientific community, but not yet documented in formal scientific literature. The underlying causes of recovery remain unclear, but resistance to RHDV infection has been reported in laboratory studies of wild-caught rabbits. Aims We document numerical changes in two South Australian wild rabbit populations that were initially suppressed by RHDV, and examine serological data to evaluate several alternative hypotheses for the cause of recovery. Methods Rabbit numbers were assessed from spotlight transect counts and dung mass transects between 1991 and 2011, and age and RHDV antibody sero-prevalence were estimated from rabbits shot in late summer. Key results Rabbit numbers were heavily suppressed by RHDV between 1995 and 2002, then increased 5-to 10-fold between 2003 and 2010. During the period of increase, annual RHDV infection rates remained stable or increased slightly, average age of rabbits remained stable and annual rainfall was below average. Conclusions Rabbit populations recovered but neither avoidance of RHDV infection, gradual accumulation of long-lived RHD-immune rabbits, nor high pasture productivity were contributing factors. This leaves increased annual survival from RHDV infection as the most likely cause of recovery. Implications Previously documented evidence of resistance to RHDV infection may be of little consequence to post-RHD recovery in rabbit numbers, unless the factors that influence the probability of infection also shape the course of infection and affect survival of infected rabbits. © 2014 CSIRO. Source

Losio M.,Istituto Zooprofilattico Sperimentale della Lombardia e dellEmilia | Pavoni E.,Istituto Zooprofilattico Sperimentale della Lombardia e dellEmilia
Industrie Alimentari | Year: 2011

An investigation on the presence of Listeria Monocytogenes (L. monocytogenes) in semi-preserved seafood was carried out in the Veneto Kegion during 2009-2010. Each sample was composed ol three subunits and each ol these was incubated at different temperatures (4° and 10°C). The presence of L. monocytogenes together with other microbiological and physicalchemical parameters were evaluated the last day of the shelf-life period. The presence ot live Listeria Monocytogenes was found in 9 of the 38 samples analysed and 3 of these samples were potentially dangerous lor humans because the L. monocytogenes cell count was higher than the limit fixed by EU Regulations. Only the products with favourable characteristics for L. monocytogenes growth were positive. At the following PCR testing 12 samples were found to be positive for L. monocytogenes The genetic characterization by means of a Riboprinter analyzer emphasized the presence of L. monocytogenes with different genotypic features, showing the need for further investigation in order to understand the behaviour of this food borne pathogen and its epidemiological characteristics. Source

Costa M.C.,economics and Food Safety Standards Authority ASAE | Goumperis T.,European Food Safety Authority | Andersson W.,Food Safety Authority of Ireland | Badiola J.,Spanish Food Safety and Nutrition Agency AESAN | And 21 more authors.
Food Control | Year: 2016

The European Food Safety Authority (EFSA) established an Emerging Risks Exchange Network (EREN) to exchange information between EFSA and the Member states (MSs) on possible emerging risks for food and feed safety in 2010. The Network is composed of delegates from MSs and Norway designated through the Advisory Forum of EFSA and observers from the European Commission, EU pre-accession countries, the Food and Drug Administration of the USA and the Food and Agricultural Organisation of the United Nations. Through 2010 to 2014, the EREN met 12 times. The EREN discussed a total of 63 signals of potential emerging issues that were presented and assessed using a standard template developed by the Emerging Risks unit of EFSA (EMRISK). Out of these signals, 39 originated from EFSA, 24 from MSs. The issues discussed were mainly microbiological and chemical hazards, but also food safety issues as result of illegal activity, new consumer consumption trends, biotoxins, new technologies and processes, allergens, animal health, environmental pollution, new analytical methods, new food packaging technology and unknown hazards were on the agenda. Based on the available evidence, EREN recommended whether an issue should be considered emerging or not, and if it merited further consideration, such as generating data on the issue, starting a full risk assessment and/or consultation of other bodies. According to the emerging risks identification process set in place at EFSA, the issues discussed and found of relevance by EREN were sent to the EFSA's Scientific Committee Standing Working Group on Emerging Risks for final evaluation. With four case studies, i.e the zoonotic potential of Usutu virus, risk of ciguatera fish poisoning in EU, zoonotic aspects of illegally imported wildlife products and benefits and risks of 3D food printing, the method developed to preliminary assess signals of potential emerging issues is presented and discussed. © 2016 Elsevier Ltd. Source

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