Epidemiological study on porcine circovirus type 2 (PCV2) infection in the European wild boar (Sus scrofa)

Abstract

-Porcine circovirus type 2 (PCV2) is considered as the causative agent of postweaning multisystemic wasting syndrome (PMWS) in domestic pigs, where the virus is ubiquitous as evidenced by serological surveys. We present the results of the first nationwide sero-survey on the presence of PCV2 antibodies in European wild boars, and report the first PMWS case in a wild boar from Spain. Sera from 656 hunter harvested wild boars from 45 different geographical sites and 22 additional imported animals were analysed by means of an immunoperoxidase monolayer assay (IPMA). We also examined the tissues from 55 healthy and one diseased wild boars for the presence of PCV2 nucleic acid and PMWS lesions by in situ hybridisation and histopathology, respectively. Additionally, abundance estimates of wild boars and field interviews were carried out on 30 sampling sites. The prevalence of medium to high PCV2 serological titres among the examined wild boars was 47.89 ± 1.9%. Seropositive wild boars appeared in all but one of the geographical regions analysed. Seroprevalence and titre of PCV2 antibodies were closely related to the management of the wild boar populations. Wild boars from intensively managed, farm-like populations had higher prevalence than wild boars living in more natural situations. The effect of wild boar abundance and management on PCV2 antibody prevalence was further evidenced by the high correlation existing between the relative abundance estimates of animals and the percentage of wild boars with medium to high levels of PCV2 antibodies. PCV2 nucleic acid was detected in the tissues of three wild boars. One of these was diagnosed as PMWS. The results, in addition to information on piglet mortalities, suggest a potential role of PMWS in piglet mortality in intensively managed wild boar populations.

Risk factors associated with the prevalence of tuberculosis-like lesions in fenced wild boar and red deer in south central Spain

“…The main finding of the present study is the association between the aggregation of hosts (mainly a consequence of hunting management in Mediterranean habitats) and the presence of TBL in potential TB reservoirs. Previous reports suggested similar relationships for other infectious pathogens in the study area [31]. Our spatial analyses of the TBL pattern across estates revealed that management units close together in space did not tend to be similar in terms of TBL prevalence, which suggests that there was no spatial aggregation (which would lead to spatial autocorrelation in our data).…”

“…Wild boar relative abundance estimates were based on dropping frequency counts [31]. Briefly, each count consisted of N = 40 transects of 100 m, divided into 10 sectors of 10 m in length.…”

Monitoring wild pig populations: a review of methods

“…Large plots are generally needed to ensure at least one dung sample can be detected per plot (Hone and Martin 1998;Hone 2012). Although swine population indexing using dung counts has been conducted without prior clearing of dung observation stations (Vicente et al 2004), once stations are defined, it is best to clear each station of existing dung. After an a priori defined and fixed period of time, the station is again searched and dung counted.…”

Detection and Genetic Characterization of Porcine Circovirus 2 Isolates From the First Cases of Postweaning Multisystemic and Wasting Syndrome in Wild Boars in Greece

“…A PCV2-antibody prevalence of 47% has been reported for wild boar sampled in Spain; antibody prevalence was highest in intensively managed populations rather than in those living in more natural conditions (Vicente et al, 2004). In addition, the incidence of PCV2 DNA in tissue samples from wild boars sampled in Hungary was 20.5% (Csagola et al, 2006).…”

“…Wild boars (Sus scrofa) infected with PCV2 have been reported (Vicente et al, 2004;Knell et al, 2005;Csagola et al, 2006). A PCV2-antibody prevalence of 47% has been reported for wild boar sampled in Spain; antibody prevalence was highest in intensively managed populations rather than in those living in more natural conditions (Vicente et al, 2004).…”