Epidemiology of Schmallenberg Virus in European Bison (Bison Bonasus) in Poland

Abstract

Schmallenberg virus (SBV), an emerging arbovirus in Europe, is an important pathogen in domestic ruminants; however, its impact on free-ranging wild ruminants is not well studied. Three hundred and forty-seven serum samples collected between 2011 and 2016 from 302 European bison ( Bison bonasus) from 12 different sites in Poland were tested for the presence of SBV antibodies. In addition, 86 sera were collected between 2013 and 2016 from three species of cervids for testing for SBV antibodies. After the first detection of the virus in Poland in October 2012, the proportion of SBV-seropositive European bison reached 81% (95% confidence interval [CI]: 77.1-85.8%), whereas in cervids seroprevalence was 34% (95% CI: 23.5-43.9%). There was an increase in seroprevalence in European bison from 2012 to 2014. Biting midges ( Culicoides spp.), the primary vectors of SBV, were monitored entomologically for the identification of the biting midge populations and virologically for SBV infections in the Białowieża Forest region, which contains the world's largest European bison population. We detected SBV by PCR in 3% of Culicoides pools from 2015. In addition, seven fetal brain samples from European bison or cervids were tested and were negative for SBV RNA. Our results indicate a high seroprevalence with reduced transmission of SBV in subsequent years in the European bison populations and lower seroprevalence in cervids.

Infectious Disease Monitoring of European Bison (Bison bonasus)

“…SBV in utero infections may lead to congenital malformations of newborns, stillbirths, or abortions. Limited access to the material of aborted fetus in the wild European bison did not allow to draw many conclusions [73]; however some losses in reproduction rate may be expected as observed in cattle.…”

“…Notwithstanding, the most important consequences of the occurring of BT are the culling of diseases or suspected animals and restrictions on the movement of animals, since the disease is notifiable disease listed by the World Organization. Control or eradication of BTV in protected wild species such as European bison is rather doomed, especially that the environment provides more susceptible species such as cervids and favorable conditions for midge reproduction and survival [72,73]. BTV epidemiological situation remains under continuous supervision (unpublished data).…”

“…The midges are active at night; therefore the trap was set on from dusk till dawn once a week during the vector activity season (April-October). UV light attracts the insects, which were trapped and fell down into the jar containing water with detergent [73].…”

“…Infectious Disease Monitoring of European Bison (Bison bonasus) DOI: http://dx.doi.org /10.5772/intechopen.84290 wild ruminants at Białowieża Forest, what allowed to determined that the transmission of SBV occurred during 2012 Culicoides activity season [76]. Further studies concentrated on the epidemiology of SBV in European bison and the environment (other susceptible species, vector) [11,73,78]. SBV seroprevalence in European bison in all studies was significantly much higher than observed in the cervids sampled simultaneously at the same locations.…”

“…Since the transmission of arthropod-borne pathogens involves environmental factors, entomological and virological studies of the midges near European bison were performed between 2014 and 2015 [73]. Using specially designed ultraviolet (UV) light traps (Figure 7c) placed near European bison resting places at Białowieża National Park abundance, species composition and virus exposure were tested.…”