African Swine Fever (ASF) is an important contagious haemorrhagic viral disease affecting swine whose notification is mandatory due to its high mortality rates and the great sanitary and socioeconomic impact it has on international trade in animal and swine products.This disease only affects porcine species, both wild and domestic, and produces a variety of clinical signs such as fever and functional disorders of the digestive and respiratory systems. Lesions are mainly characterized by congestive-haemorrhagic alterations. ASF epidemiology varies significantly between countries, regions and continents, since it depends on the characteristics of the virus in circulation, the presence of wild hosts and reservoirs, environmental conditions and human social behaviour. Furthermore, a specific host will not necessarily always play the same active role in the spread and maintenance of ASF in a particular area.Currently, ASF is endemic in most sub-Saharan African countries where wild hosts and tick vectors (Ornithodoros) play an important role acting as biological reservoirs for the virus. In Europe, the disease has been endemic since 1978 on the island of Sardinia (Italy) and since 2007, when it was first reported in Georgia, in a number of Eastern European countries. It is also endemic in certain regions of the Russia Federation, where domestic pig and wild boar populations are widely affected. By contrast, in the affected eastern European Union (EU) countries where ASF is currently as epidemic, the on-going spread of the disease affects mainly wild boar populations located in restricted areas and, to a much less extent, domestic pigs. Unlike most livestock diseases, no vaccine or specific treatment is currently available for ASF. Therefore, disease control is mainly based on early detection and the application of strict sanitary and biosecurity measures. Epidemiology of ASF is very complex by the existence of different virus circulating, reservoirs and a number of scenarios, and the on-going spread of the disease through Africa and Europe. Survivor pigs can remain persistently infected for months which may contribute to virus transmission and thus the spread and maintenance of the disease, thereby complicating attempts to control it.
African swine fever (ASF) has caused the swine industry of the Russian Federation substantial economic losses over the last 7 years, and the disease spread from there to a number of neighbouring countries. Wild boar has been involved in the spread of the disease both at local and at transboundary levels. Understanding ASF dynamics in wild boars is prerequisite to preventing the spread and to designing and applying effective surveillance and control plans. The reproductive ratio (R ) is an epidemiological indicator commonly used to quantify the extent of disease spread. Here, it was estimated in nine spatio-temporal clusters of ASF in wild boar cases in the Russian Federation (2007-2013). Clusters were defined by exploring the maximum distance of association of ASF cases using K Ripley analysis and spatio-temporal scan statistics. A maximum spatial association of 133 km in wild boar cases was identified which is within de the conventional radius of surveillance zone (100-150 km). The mean range value of R = 1.58 (1.13-3.77) was lower compared to values previously estimated for ASF transmission within farms but similar to early estimates between farm (R = 2-3), in domestic pigs using notification data in the Russian Federation. Results obtained provide quantitative knowledge on the epidemiology of ASF in wild boars in the Russian Federation. They identify the ASF transmission rate value in affected natural wild populations, for the first time, which could provide basis for modelling ASF transmission and suggest that current surveillance radius should be reviewed to make surveillance in wild nature more targeted and effective.
Summary Crimean‐Congo haemorrhagic fever virus (CCHFV) is one of the most widespread of all medically important arboviruses with ticks of the Hyalomma spp. serving as the main vectors. Infection of livestock by CCHFV serves as a route of exposure to humans, as a reservoir of disease and as a route of importation. This study discusses the pathways and data requirements for a qualitative risk assessment for the emergence of CCHFV in livestock in Europe. A risk map approach is proposed based on layers that include the potential routes of release (e.g. by migrating birds carrying infected ticks) together with the main components for exposure, namely the distributions of the tick vectors, the small vertebrate host reservoirs and the livestock. A layer on landscape fragmentation serves as a surrogate for proximity of livestock to the tick cycle. Although the impact of climate change on the emergence of CCHF is not clear, comparing the distribution of risk factors in each layer currently with those predicted in the 2080s with climate change can be used to speculate how potential high‐risk areas may shift. According to the risk pathway, transstadial and/or transovarial transmission in the tick vector are crucial for CCHFV spread. Vector competence and tick vector switching, however, remain critical factors for CCHFV colonization of new regions in Europe. The species of migratory bird is also an important consideration in the release assessment with greater abundance and biodiversity of ground‐dwelling birds in southern Europe than in northern Europe.
To predict the risk of incursion of Crimean-Congo haemorrhagic fever virus (CCHFV) in livestock in Europe introduced through immature Hyalomma marginatum ticks on migratory birds under current conditions and in the decade 2075-2084 under a climate-change scenario. A spatial risk map of Europe comprising 14 282 grid cells (25 × 25 km) was constructed using three data sources: (i) ranges and abundances of four species of bird which migrate from sub-Saharan Africa to Europe each spring, namely Willow warbler (Phylloscopus trochilus), Northern wheatear (Oenanthe oenanthe), Tree pipit (Anthus trivialis) and Common quail (Coturnix coturnix); (ii) UK Met Office HadRM3 spring temperatures for prediction of moulting success of immature H. marginatum ticks and (iii) livestock densities. On average, the number of grid cells in Europe predicted to have at least one CCHFV incursion in livestock in spring was 1·04 per year for the decade 2005-2014 and 1·03 per year for the decade 2075-2084. In general with the assumed climate-change scenario, the risk increased in northern Europe but decreased in central and southern Europe, although there is considerable local variation in the trends. The absolute risk of incursion of CCHFV in livestock through ticks introduced by four abundant species of migratory bird (totalling 120 million individual birds) is very low. Climate change has opposing effects, increasing the success of the moult of the nymphal ticks into adults but decreasing the projected abundance of birds by 34% in this model. For Europe, climate change is not predicted to increase the overall risk of incursion of CCHFV in livestock through infected ticks introduced by these four migratory bird species
The pharmacokinetics of ciprofloxacin (CIP) following intravenous administration in dogs have been investigated. The drug was administered at three doses (2.5, 5 and 10 mg/kg body weight) and was assayed in biological fluid samples (plasma and urine) by an HPLC method. The plasma concentration-time curves were best described by a two-compartment open pharmacokinetic model. The drug was widely distributed (Vd(area) almost 3 l/kg), being distributed in the dog more rapidly than in other species (t1/2(lambda 1) 3 min approximately). The elimination half-life (t1/2 lambda 2) was 129-180 min which is similar to values obtained in other species. The unchanged drug eliminated in urine was less than 37% of the administered dose, which is less than the values obtained in humans, calves and pigs. The glomerular filtration rate and the renal clearance of CIP in the dog suggest that renal elimination probably occurs mainly by glomerular filtration. The results showed that the pharmacokinetics of CIP, as in other species, was linear in dogs in the dose range studied.
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