Semi-quantitative risk assessment of peste des petits ruminants introduction with wild animals into Russian Federation

The Russian Federation was officially recognized free from peste des petitts ruminants (PPR). As far as the disease infects both domestic and wild small ruminants, it is important to identify the level of the threat associated with the wild fauna diversity in the neighboring countries, where PPR outbreaks were reported. For that reason, habitats of various disease susceptible animal species were examined. Habitats of the wild susceptible animals were mapped for further examination of the interactions between different animal species using zoological research data; PPR outbreaks in wild animals were also designated in the map thus allowing for the detection of the potential routes of the infection spread in the population and introduction to the country. Analysis of the PPR epidemic situation in the country demonstrated that the disease cases were reported in wild mountain animals (ibices and moufflons) and migratory steppe animals (gazelles and saigas). Risk of this highly contagious viral disease spread in wild small ruminants in Mongolia was reported (probability 0.77). Expert survey was carried out for the determination of possible trends and factors of the infection introduction with the wild susceptible animals, through which small ruminant epizootologists assessed the risk probability. During the survey it was determined that PPR was expected to be introduced from Mongolia (probability 0.81), and of major significance were seasonal migrations of wild animal populations. The resulted semi-quantitative parameters of the potential risk can be recommended for the arrangement and implementation of measures aimed at prevention of PPR introduction and spread in the intact domestic and wild small ruminant populations inhabiting the territory of the Russian Federation

Spatiotemporal analysis of African swine fever spread in wild boar population in Russian Federation, 2007–2022

African swine fever is a transboundary disease of all members of Suidae family andit causes economic damage to the pigindustry and ecology of wild boar as a species. The ASF epidemiology is complex andit is specifiedby the mechanismsof the agent’s transmission in susceptible animal populations. Choiceof measure saimed to control and prevent the disease spreadin the wild boar population depends mainly on the routes of the disease introduction and stage or phase of the epizootic process. Prevention of the ASFV introduction from an infected region to a free one is the back bone in the infection prevention. Therefore, there search was aimed at the spatiotemporal analysis of African swine feveroutbreaks in the wild boar population in the Russian Federation in 2007–2022 and identification of geographical are as that poser is kof new disease epidemics. The analysis was performed using retrospective space-timescan statistics, which does not require data on the wild boar population and which can beused for the assessment of the possibility of new ASFoutbreak occurrence upon availability of just data on the reported disease case sand out breaks. As are sult of spatiotem poral cluster analysis, 24 clusters of ASF out breaks were identified based on the laboratory-confirmed data on the infection in boars found dead, and 22 clusters in hunted wildboars. The analysis results demonstrated spatial heterogeneity of the outbreak cluster distribution in population of wildboarsdied of the disease and a significant expansion of the passive surveillance geography. Importance and necessity of the enhanced passive surve illance of African swinefever in susceptible animals is demonstrated. The proposed methodcan beused for regular scanning of age ographic region for the presence of developing zone sand areasat risk of re-emerging ASFoutbreaks in the wildboar population at different spatial scales

Density of wild boar population and spread of African swine fever in the Russian Federation

African swine fever (ASF) is a transboundary viral disease affecting all species of the Suidae family. It greatly undermines global pig industry and causes a significant damage to the ecology of the wild boar (Sus scrofa) which is a natural reservoir of the virus and is an intermediate  link in the epizootic process. Depopulation of wild boars is one of the measures taken to prevent spread of African swine fever in the Russian Federation. A threshold density of the wild boar population of 0.25 boars/1000 ha (0.025 boars/km2), according to the National Plan on the ASF Eradication in the Russian Federation, was achieved by 2020 in many RF Subjects. However, further analysis of the ASF epizootic situation shows that the measure has failed to eradicate the infection completely. A regression analysis showed statistically significant positive relationship between recurrent ASF outbreaks in the wild boar population and its density in a number of model subjects (N = 6). At the same time, there is no such dependence in other model subjects (N = 3), and  ASF outbreaks were recorded in wild boars at a density significantly lower than the recommended value. A review of foreign and national scientific publications has shown that such control methods as depopulation is just one part of the whole set of measures taken to eradicate African swine fever in the wild. The measure  is effective only when 70–80%  of animals are culled in a short time, which is practically impossible due to the high costs and some peculiarities of the population control and depopulation  process. Based on the results obtained, it can be concluded that a decrease in the number of wild boars does not guarantee to stop further spread of infection in the Russian Federation and it should be considered as just one part of the whole set of measures taken together with other anti-epizootic measures to eliminate and prevent ASF

AFRICAN SWINE FEVER EPIDEMIC IN 2007–2017 PART 1. COMMON TRENDS FOR ASF IN THE RUSSIAN FEDERATION AND IN EURASIA

Results of retrospective analysis of African swine fever epidemic situation in the Russian Federation including analysis of the epidemic chronology indicating significant events of the disease spread across the country territory are presented. Common ASF epidemic trend and rate in 2007–2017 in Eurasia territory based on number of infected countries (1.273 ± 1.272 countries/year) and in Russian Federation Subjects (4.5 ± 2.3 Subjects/year) are shown. The paper also addresses some peculiarities of the epidemic process depending on the season of a year. Possible social and biological factors contributing to the epidemic spread are examined. Necessity of further search for probable biological vector and examination of social factors that could contribute to the disease maintenance in wild life and in domestic pigs in the Russian Federation and Eastern European countries are discussed

Classical swine fever: a retrospective analysis of the epizootic situation in the Russian Federation (2007–2021) and forecast for 2022

The paper presents trends in the epizootic situation on classical swine fever (CSF) in the Russian Federation, for 2007–2021. Most likely, a drop in the number of CSF outbreaks throughout the country results from two factors: a geographical shift of the disease outbreaks from the European part of Russia to the eastern regions bordering on China (into the wild boar population), as documented between 2015 and 2021, and a large-scale vaccination of domestic pigs practiced in the recent years. The introduction and spread of CSF in the Russian Federation are, most likely, associated with the internal risk factors (i.e. quality of anti-epizootic measures, mainly vaccination) and with the territories, where the virus circulates in wild boars. Expansion of vaccination coverage since 2011 is one of the factors contributing to a decrease in the number of clinical CSF cases registered in domestic pigs of the Russian Federation. The infection spread in domestic pigs is still on a downward trend. For purposes of analysis, current trends of CSF spread in domestic pigs and wild boars in the Russian Federation, as well as the volume of the vaccine used, were visualized in relative numbers (taking into account total number of pigs in the country) used to build a regression model. Currently, vaccination against classical swine fever in the Russian Federation (and its good quality) is an essential prerequisite to contain the infection spread in the country

Basic reproduction number for certain infectious porcine diseases: estimation of required level of vaccination or depopulation of susceptible animals

Basic reproduction number (R0) is one of the fundamental quantitative characteristics in epidemiology of infectious human and animal diseases. This parameter reflects the biological properties of the infectious agent, the social and economic aspects of animal husbandry, natural factors associated with the habitat of the animal population invaded by the virus (microorganism), as well as the effectiveness of methods selected for infection control, in particular, the implementation of preventive measures; it also allows foreseeing the number and probability of occurrence of new secondary outbreaks in the area at risk of the disease spread. The paper presents data on the estimation of basic reproduction number (R0) for a range of infectious porcine diseases. A systematic analysis has been undertaken with respect to the publications available on the estimation of R 0 for various virus isolates of African swine fever, classical swine fever, foot-and-mouth disease, porcine reproductive and respiratory syndrome, Aujeszky’s disease, hepatitis E, encephalomyocarditis, porcine circovirus type 2, as well as pleuropneumonia associated with Actinobacillus pleuropneumoniae, and diseases caused by pathogenic isolates of Mycoplasma hyopneumoniae. Based on the obtained R0 values, recommendations for the veterinary services are made on preventive vaccination of pigs against the above mentioned diseases in the areas at risk of infection spread. The necessary conditions for wild boar depopulation aimed to prevent new African swine fever outbreaks are identified, namely, the elimination of at least 75% of the wild boar population living in the risk zone within the period of time equal to one infectious period

AFRICAN SWINE FEVER ZONING OF THE RUSSIAN FEDERATION TERRITORY

Possibility and efficacy of African swine fever (ASF) zoning of the Russian Federation (RF) territory and compartmentalization of pig establishments are discussed in the paper. The main goal of thezoning programme is creation of independent zones with different zoo-sanitary status where enhanced surveillance (passive and target) will be carried out and movements of ASF-susceptible live pigs and porcine products between the zones will be restricted. Approval and validation of the programme on ASF zoning of the RF territory will allow reduction (minimization) of risks of possible disease spread to the ASF-free zone as well as achieving the main goal - gaining and maintaining ASF-free status in the whole territory of the country. Moreover, successful programme on pig establishment compartmentalization will allow international trade in pork and porcine products from both ASF-free and ASF-affected zones in case of the disease occurrence in the affected zones

Evaluation of rabies control measure effectiveness in the Russian Federation

Rabies is a zooanthroponotic disease, causing significant economic damage, resulting from losses due to livestock deaths, costs of preventive measures and diagnostic tests. The disease is transmitted through biting or licking of damaged skin or mucosa. The disease is absolutely fatal and practically all warm-blooded animals are susceptible to it. The paper presents the analysis of statistical data on rabies morbidity and mortality among humans and animals; the assessment of epidemic situation in the Russian Federation, including the target population vaccination coverage and effectiveness evaluation of measures, taken in Russia to prevent rabies spread. The major causes of human mortality are considered. The recommendations on decreasing the disease spread risks are given. It was established that about 60 thousand human deaths and 45 thousand animal deaths from rabies have been reported in the Russian Federation within the past 10 years (from 2010 to 2019). Moreover cases of licking/scratching/biting of humans (397,248 cases in 2019, out of them 10,232 by wild animals) are reported every year. The sources of human infection within the mentioned period were dogs (39%), foxes (18%), cats (14%), raccoon dogs (14%), wolves (4%), polar foxes (4%), ferrets (4%), unknown sources (3%). The analysis of data from veterinary reports showed that the most rabies-infected regions are the Central and Volga Federal Districts. Using the mathematical modeling of the epidemic process the results of preventive measures, taken by the Veterinary Service in case of rabies in the region, were evaluated

Spatio-temporal modeling of the African swine fever epidemic in the Russian Federation, 2007-2012

© 2014 Elsevier Ltd. In 2007 African swine fever (ASF) entered Georgia and in the same year the disease entered the Russian Federation. From 2007 to 2012 ASF spread throughout the southern region of the Russian Federation. At the same time several cases of ASF were detected in the central and northern regions of the Russian Federation, forming a northern cluster of outbreaks in 2011. This northern cluster is of concern because of its proximity to mainland Europe. The aim of this study was to use details of recorded ASF outbreaks and human and swine population details to estimate the spatial distribution of ASF risk in the southern region of the European part of the Russian Federation. Our model of ASF risk was comprised of two components. The first was an estimate of ASF suitability scores calculated using maximum entropy methods. The second was an estimate of ASF risk as a function of Euclidean distance from index cases. An exponential distribution fitted to a frequency histogram of the Euclidean distance between consecutive ASF cases had a mean value of 156. km, a distance greater than the surveillance zone radius of 100-150. km stated in the ASF control regulations for the Russian Federation. We show that the spatial and temporal risk of ASF expansion is related to the suitability of the area of potential expansion, which is in turn a function of socio-economic and geographic variables. We propose that the methodology presented in this paper provides a useful tool to optimize surveillance for ASF in affected areas