scholarly journals Efficacy of Oral Vaccine against Classical Swine Fever in Wild Boar and Estimation of the Disease Dynamics in the Quantitative Approach

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 319
Author(s):  
Enkhbold Bazarragchaa ◽  
Norikazu Isoda ◽  
Taksoo Kim ◽  
Madoka Tetsuo ◽  
Satoshi Ito ◽  
...  
Keyword(s):  
Wild Boar ◽  
Oral Vaccine ◽  
Classical Swine Fever ◽  
Control Measures ◽  
Wild Boar Population ◽  
Oral Vaccination ◽  
Wild Boars ◽  
In The Wild ◽  
High Virus ◽  
Gifu Prefecture

Classical swine fever virus (CSFV) in the wild boar population has been spreading in Japan, alongside outbreaks on pigs, since classical swine fever (CSF) reemerged in September 2018. The vaccination using oral bait vaccine was initially implemented in Gifu prefecture in March 2019. In the present study, antibodies against CSFV in wild boar were assessed in 1443 captured and dead wild boars in Gifu prefecture. After the implementation of oral vaccination, the increase of the proportion of seropositive animals and their titer in wild boars were confirmed. Quantitative analysis of antigen and antibodies against CSFV in wild boar implies potential disease diversity in the wild boar population. Animals with status in high virus replication (Ct < 30) and non- or low-immune response were confirmed and were sustained at a certain level after initial oral vaccination. Through continuous vaccination periods, the increase of seroprevalence among wild boar and the decrease of CSFV-positive animals were observed. The epidemiological analysis based on the quantitative virological outcomes could provide more information on the efficacy of oral vaccination and dynamics of CSF in the wild boar population, which will help to improve the implementation of control measures for CSF in countries such as Japan and neighboring countries.

scholarly journals Epidemiological analysis of classical swine fever in wild boars in Japan

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Yumiko Shimizu ◽  
Yoko Hayama ◽  
Yoshinori Murato ◽  
Kotaro Sawai ◽  
Emi Yamaguchi ◽  
...  
Keyword(s):  
Wild Boar ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Classical Swine Fever ◽  
Disease Spread ◽  
Wild Boar Population ◽  
Wild Boars ◽  
First Case ◽  
Forest Continuity ◽  
In The Wild

Abstract Background Classical swine fever (CSF) is a contagious disease of pigs and wild boars that is transmitted through direct/indirect contact between animals or CSF virus-contaminated fomites. When the disease re-emerged in 2018 in Japan, a CSF-infected wild boar was reported shortly after the initial pig farm outbreak; subsequently, the disease spread widely. To control the disease spread among wild boars, intensive capturing, fencing, and oral bait vaccination were implemented with concomitant virological and serological surveillance. This study aimed to describe the disease spread in the wild boar population in Japan from September 2018, when the first case was reported, to March 2020, based on the surveillance data. We conducted statistical analyses using a generalized linear mixed model to identify factors associated with CSF infection among wild boars. Moreover, we descriptively assessed the effect of oral bait vaccination, which started in March 2019 in some municipalities in the affected areas. Results We observed a faster CSF infection spread in the wild boar population in Japan compared with the CSF epidemics in European countries. The infection probability was significantly higher in dead and adult animals. The influence of the multiple rounds of oral bait vaccination was not elucidated by the statistical modeling analyses. There was a decrease and increase in the proportion of infected and immune animals, respectively; however, the immunization in piglets remained insufficient after vaccination for 1 year. Conclusions Conditions regarding the wild boar habitat, including forest continuity, higher wild boar population density, and a larger proportion of susceptible piglets, were addressed to increase the infection risk in the wild boar population. These findings could improve the national control strategy against the CSF epidemic among wild boars.

scholarly journals Prevalence and Antimicrobial Resistances of Salmonella spp. Isolated from Wild Boars in Liguria Region, Italy

Pathogens ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 568
Author(s):  
Elisabetta Razzuoli ◽  
Valeria Listorti ◽  
Isabella Martini ◽  
Laura Migone ◽  
Lucia Decastelli ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Wild Boar ◽  
Antimicrobial Susceptibility ◽  
Potential Risk ◽  
Salmonella Enterica ◽  
Intestinal Tract ◽  
Wild Boar Population ◽  
Salmonella Spp ◽  
Wild Boars ◽  
In The Wild

Salmonella spp. is an important zoonotic agent. Wild boars might host this pathogen in the intestinal tract and might represent a risk for Salmonella spp. transmission to humans. Wild boars are widely spread in Liguria, due to the environmental characteristics of the region. The aim of the study was the isolation, typing, and investigation of antimicrobial susceptibility of the isolated strains of Salmonella spp. During the 2013–2017 hunting seasons, 4335 livers of wild boars were collected and analyzed for the presence of Salmonella spp. A total of 260 strains of Salmonella spp. were isolated and characterized, with a prevalence of 6%. The isolated strains belonged to all six Salmonella enterica subspecies. Most of them were identified as Salmonella enterica subs. enterica of which 31 different serotypes were identified. The dominating serotype identified was S. Enteritidis. The antimicrobial resistance profiles of the isolated strains were analyzed against sixteen molecules. Of the isolated strains, 94.6% were resistant to at least one of the tested antimicrobials. This study showed the circulation of resistant Salmonella spp. strains in the wild boar population living in this area of Italy, underling the potential risk for these animals to disseminate this pathogen and its antimicrobial resistances.

scholarly journals Role of Wild Boar in the Spread of Classical Swine Fever in Japan

Pathogens ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 206 ◽  
Author(s):  
Ito ◽  
Jurado ◽  
Bosch ◽  
Ito ◽  
Sánchez-Vizcaíno ◽  
...  
Keyword(s):  
Wild Boar ◽  
Spatial Association ◽  
Classical Swine Fever ◽  
Temporal Analysis ◽  
Control Measures ◽  
Domestic Pig ◽  
Potential Contact ◽  
Spatio Temporal ◽  
Epidemiological Characteristics ◽  
Gifu Prefecture

Since September 2018, nearly 900 notifications of classical swine fever (CSF) have been reported in Gifu Prefecture (Japan) affecting domestic pig and wild boar by the end of August 2019. To determine the epidemiological characteristics of its spread, a spatio-temporal analysis was performed using actual field data on the current epidemic. The spatial study, based on standard deviational ellipses of official CSF notifications, showed that the disease likely spread to the northeast part of the prefecture. A maximum significant spatial association estimated between CSF notifications was 23 km by the multi-distance spatial cluster analysis. A space-time permutation analysis identified two significant clusters with an approximate radius of 12 and 20 km and 124 and 98 days of duration, respectively. When the area of the identified clusters was overlaid on a map of habitat quality, approximately 82% and 75% of CSF notifications, respectively, were found in areas with potential contact between pigs and wild boar. The obtained results provide information on the current CSF epidemic, which is mainly driven by wild boar cases with sporadic outbreaks on domestic pig farms. These findings will help implement control measures in Gifu Prefecture.

scholarly journals Does the infection with endoparasites influence the effect of oral vaccination against classical swine fever in wild boar?

2015 ◽  
Vol 84 (3) ◽  
pp. 225-230
Author(s):  
Anna Ondrejková ◽  
Ondrej Kiš ◽  
Juraj Ciberej ◽  
Katarína Oberhauserová ◽  
Róbert Ondrejka ◽  
...  
Keyword(s):  
Wild Boar ◽  
Classical Swine Fever ◽  
Viral Disease ◽  
Economic Losses ◽  
Parasitic Infections ◽  
Oral Vaccination ◽  
Specific Antibodies ◽  
Antibody Titres ◽  
In The Wild ◽  
Direct Elisa

Classical swine fever is a highly contagious viral disease that affects domestic and wild suids and could cause important economic losses. It is the most dangerous infectious disease of the wild boar that can cause severe death in densely populated areas. The aim of the study was to determine the effect of endoparasites on the oral vaccination against classical swine fever in wild boar. The study compared classical swine fever antibody titres in wild boar treated and untreated with antiparasitics. Fourteen six-month-old wild boar piglets were tested via direct ELISA to detect specific antibodies in blood serum after vaccination. Before the vaccination, one group of piglets was administered antiparasitic therapy; the other group of animals remained untreated. Twenty-eight days post vaccination, piglets from the first group (free of parasites) showed significantly (P = 0.0015) higher concentrations of specific antibodies than the infected animals. Obtained results proved that parasitic infections substantially influence the efficacy of oral vaccination against classical swine fever and may support the ability of the virus to produce infectious diseases and its transmission in the wild boar population. For that reason, antiparasitic therapy of wild boar populations before their vaccination is highly recommended in order to increase the vaccine’s efficacy.

scholarly journals Dynamics of Classical Swine Fever Spread in Wild Boar in 2018–2019, Japan

Pathogens ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 119 ◽  
Author(s):  
Norikazu Isoda ◽  
Kairi Baba ◽  
Satoshi Ito ◽  
Mitsugi Ito ◽  
Yoshihiro Sakoda ◽  
...  
Keyword(s):  
Wild Boar ◽  
Euclidean Distance ◽  
Classical Swine Fever ◽  
Control Measures ◽  
Anthropogenic Factors ◽  
Epidemiological Analysis ◽  
Period Prevalence ◽  
Positive Rate ◽  
In The Wild ◽  
Spatiotemporal Analyses

The prolongation of the classic swine fever (CSF) outbreak in Japan in 2018 was highly associated with the persistence and widespread of the CSF virus (CSFV) in the wild boar population. To investigate the dynamics of the CSF outbreak in wild boar, spatiotemporal analyses were performed. The positive rate of CSFV in wild boar fluctuated dramatically from March to June 2019, but finally stabilized at approximately 10%. The Euclidean distance from the initial CSF notified farm to the farthest infected wild boar of the day constantly increased over time since the initial outbreak except in the cases reported from Gunma and Saitama prefectures. The two-month-period prevalence, estimated using integrated nested Laplace approximation, reached >80% in half of the infected areas in March–April 2019. The area affected continued to expand despite the period prevalence decreasing up to October 2019. A large difference in the shapes of standard deviational ellipses and in the location of their centroids when including or excluding cases in Gunma and Saitama prefectures indicates that infections there were unlikely to have been caused simply by wild boar activities, and anthropogenic factors were likely involved. The emergence of concurrent space–time clusters in these areas after July 2019 indicated that CSF outbreaks were scattered by this point in time. The results of this epidemiological analysis help explain the dynamics of the spread of CSF and will aid in the implementation of control measures, including bait vaccination.

scholarly journals African swine fever virus (ASFV) in Poland: Prevalence in a wild boar population (2017–2018)

2020 ◽  
Vol 65 (No. 4) ◽  
pp. 143-158 ◽  
Author(s):  
MP Frant ◽  
M Lyjak ◽  
L Bocian ◽  
A Barszcz ◽  
K Niemczuk ◽  
...  
Keyword(s):  
Wild Boar ◽  
Active Surveillance ◽  
African Swine Fever Virus ◽  
Winter Season ◽  
African Swine Fever ◽  
Disease Spread ◽  
Passive Surveillance ◽  
Wild Boar Population ◽  
Wild Boars ◽  
In The Wild

African swine fever (ASF) was first described in 1921 in Kenya. The latest epidemic of ASF started in 2007 in Georgia. The virus was introduced to Poland in 2014. Since the beginning of the epidemics, the National Veterinary Research Institute in Pulawy (NVRI) has been testing wild boar samples from restricted areas and other parts of Poland to conduct passive and active surveillance for ASFV in these groups of animals. The aim of this study was to summarise the last two years of the ASF epidemiological status in Poland and the attempt to find disease patterns in the wild boar population. The period between 2017 and 2018 brought a massive number of new ASF cases in Poland. The number of ASF-positive wild boars jumped from 91 in 2016 to 1 140 in 2017 (approximately a 12 × increase), and 2018 was even worse, with the disease affecting 4 083 animals (2 435 cases; one case could even be 10 animals or more if they are found in one place next to each other). The percentage of positive wild boars found dead (passive surveillance) in the restricted area increased in 2018 to 73.1% from 70.8% in 2017. The chance of obtaining positive results in this group was six times higher in December and 4.5 times higher in January than in August and September. The percentage of positive wild boars detected through active surveillance reached 1.5% in 2018. The data suggested that, not only in Poland, but also in other ASF-affected countries, during the epizootic stage of the disease spread the most important measure is an effective passive surveillance of dead wild boars especially, in the winter season rather than in the summer.

scholarly journals What Do Lithuanian Hunters Think of African Swine Fever and Its Control—Perceptions

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 525
Author(s):  
Evelina Stončiūtė ◽  
Katja Schulz ◽  
Alvydas Malakauskas ◽  
Franz J. Conraths ◽  
Marius Masiulis ◽  
...  
Keyword(s):  
Wild Boar ◽  
Surveillance System ◽  
African Swine Fever ◽  
Study Data ◽  
Control Measures ◽  
Attitudes And Beliefs ◽  
Passive Surveillance ◽  
Wild Boar Population ◽  
In The Wild ◽  
Governmental Institutions

After the introduction of African swine fever (ASF) into Lithuania in 2014, continuous spread of the disease resulted in infection of the wild boar populations in most parts of Lithuania. The virus has been moving closer to other Western European countries where pig density is high. An efficient surveillance system detecting ASF cases early in domestic and wild animals is necessary to manage this disease. To make surveillance appropriate and effective, it is critical to understand how key players perceive the implemented control measures. This study investigated the attitudes and beliefs of hunters in Lithuania regarding currently implemented or proposed measures for the control of ASF in the wild boar population. Study data were collected through questionnaires distributed via the internet and by hunting associations in Lithuania. In total, 621 fully completed questionnaires were received and analyzed. All measures interfering with extensive hunting, like ban of driven or individual hunting or ban of supplementary feeding were considered as unacceptable and as ineffective measures to control ASF in wild boar. However, selective hunting of female wild boar was generally considered as an unethical act and therefore rejected. Some measures that seem to have been successful in other countries, like involvement of additional forces, were rejected by Lithuanian hunters, thus implementation of these measures could be difficult. The study highlighted that there is a need for improving important relationships with other stakeholders, since many hunters expressed a lack of trust in governmental institutions and regarded cooperation with them as insufficient. Hunters emphasized that their motivation to support passive surveillance measures could be improved with financial compensation and reduction of workload. The present study provides insights into hunters’ perceptions, which may be used as a foundation for additional discussions with these important stakeholders and for adapting measures to improve their acceptance if appropriate.

scholarly journals Determination of Endoparasites by Faecal Examination in the Wild Boar Population in Vojvodina (Serbia)

2018 ◽  
Vol 41 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Igor Stojanov ◽  
Ivan Pavlović ◽  
Ivan Pušić ◽  
Jasna Prodanov-Radulović ◽  
Radomir Ratajac ◽  
...  
Keyword(s):  
Wild Boar ◽  
Parasite Species ◽  
Wild Boar Population ◽  
Laboratory Methods ◽  
Faecal Examination ◽  
Wild Boars ◽  
Faecal Samples ◽  
Potential Reservoir ◽  
In The Wild

Abstract The aim of our study was to determine whether and to what extent certain species of helminths and protozoa are present in the wild boar population living in hunting grounds in Vojvodina. For this purpose, 52 faecal samples of hunted wild boars (aged 6 months to 2 years) were examined. Examination of the faeces was performed using classical coproscopic laboratory methods. The following parasite species were identified: Metastrongylus spp. Ascaris suum, Trichuris suis, Physocephalus sexalatus, Strongyloides ransomi, Oesophagostomum sp. / Globocephalus sp., Hyostrongylus rubidus, Gnathostoma hispidum, Eimeria deblecki and Eimeria suis. The obtained results from this study indicated that wild boars are a potential reservoir of a variety of endoparasites, thus endangering the surrounding ecosystem.

scholarly journals Wild boar behaviour and the epidemiological significance of this animal species as the main reservoir of the African swine fever virus

2021 ◽  
Vol 77 (02) ◽  
pp. 6501-2021
Author(s):  
KAZIMIERZ TARASIUK ◽  
ZYGMUNT GIŻEJEWSKI
Keyword(s):  
Wild Boar ◽  
Animal Species ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Annual Growth Rate ◽  
Wild Boar Population ◽  
Wild Boars ◽  
In The Wild ◽  
To Come

Recent years (since 2013) have witnessed an increasing interest in wild boars in Europe because this animal species has become the most important reservoir of the African swine fever virus (ASFV). In all countries affected by ASF since 2013, the virus originated in wild boar populations, and the disease was directly or indirectly transmitted from wild boars to domestic pigs. In Poland, the first known case of ASF was detected in February 2014, and nearly 10 300 cases were reported by the end of April 2020. A correlation was found between the density of wild boar populations and the number of ASF cases. The global population of wild boars has increased considerably, and their natural range has expanded, particularly northward and westward. The mean annual growth rate in the wild boar population in Europe is around 100%. Milder winters and agricultural transformations that involve growing a single crop (in particular, maize) over large areas are the key factors contributing to the increase in the number of wild boars. In the opinion of most experts, recreational hunting is not sufficient to control the expansion of wild boar populations in Europe. Undoubtedly, wild boar populations will continue to be the main reservoir of the ASFV for many years to come, and wild boars will remain the major risk factor for ASF spread in commercial pig herds. Therefore, a new long-term approach to wild boar population management is needed

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