A Serologic Survey of Pathogens in Wild Boar (Sus Scrofa) in Sweden

Abstract

The wild boar ( Sus scrofa) population has increased markedly during the last three decades in Sweden and in other parts of Europe. This population growth may lead to increased contact between the wild boar and the domestic pig ( Sus scrofa scrofa), increasing the risk of transmission of pathogens. The objective of our study was to estimate the seroprevalence of selective pathogens, known to be shared between wild boars and domestic pigs in Europe, in three wild boar populations in Sweden. In total, 286 hunter-harvested female wild boars were included in this study. The sera were analyzed for antibodies against nine pathogens using different commercial or in-house enzyme-linked immunosorbent assays. Antibodies were detected against porcine parvovirus (78.0%), porcine circovirus type 2 (99.0%), swine influenza virus (3.8%), Erysipelothrix rhusiopathiae (17.5%), Mycoplasma hyopneumoniae (24.8%), and Toxoplasma gondii (28.6%). No antibodies were detected against porcine respiratory and reproductive syndrome virus, Brucella suis, or Mycobacterium bovis. Our results highlight the potential importance of the wild boar as a reservoir for pathogens potentially transmissible to domestic pigs and which also may affect human health.

Wild boars: A potential source of Erysipelothrix rhusiopathiae infection in Japan

“…The SpaA protein used in this study for the detection of anti‐ E. rhusiopathiae antibodies is not expressed in other Erysipelothrix species, including Erysipelothrix tonsillarum , which is phenotypically very similar to E. rhusiopathiae , indicating high reliability of the data. The high seropositivity in Japan was surprising in view of previous surveys in the European countries of Spain, Sweden, and Greece, in which seropositivity was reported as 15%, 17.5%, and 2.4%, respectively . The high seropositivity rate is most likely due to the high rate of carrier status: 90% (18/20) of the wild boars tested in this study carried E. rhusiopathiae in their tonsils.…”

“…The high seropositivity in Japan was surprising in view of previous surveys in the European countries of Spain, Sweden, and Greece, in which seropositivity was reported as 15%, 17.5%, and 2.4%, respectively. [14][15][16] The high seropositivity rate is most likely due to the high rate of carrier status: 90% (18/20) of the wild boars tested in this study carried E. rhusiopathiae in their tonsils.…”

Genetically similar hepatitis E virus strains infect both humans and wild boars in the Barcelona area, Spain, and Sweden

“…The increasing populations and geographical spread of the wild boars into farmlands may also cause direct and indirect contacts with and possible transmission of viruses to livestock (Jansson et al., ). Even if HEV infections in domestic pigs have low impact on herd health, the contact suggested by infections with similar HEV strains may be relevant for other pathogens with impact on farming health, such as porcine reproductive and respiratory syndrome virus, porcine circovirus, Aujeszky's diseases virus, African and classical swine fever viruses, Mycoplasma hyopneumoniae and Toxoplasma gondii , which are carried by wild boars (Boadella et al., ; Klaumann et al., ; Ruiz‐Fons, Segales, & Gortazar, ; Malmsten, Magnusson, Ruiz‐Fons, Gonzalez‐Barrio, & Dalin, ). The risks for spreading diseases from wild boars can thus increase, which could lead to losses in the livestock industry.…”

Hepatitis E virus strains infecting Swedish domestic pigs are unique for each pig farm and remain in the farm for at least 2 years

“…There may be a significant risk that direct or indirect contacts between wild boars and domestic pigs can introduce other diseases in the herds, such as porcine circovirus, Yersinia ssp., Salmonella ssp. and Toxoplasma gondii , which are all carried by Swedish wild boars (Quintern & Sundrum, ; Malmsten, Magnusson, Ruiz‐Fons, Gonzalez‐Barrio, & Dalin, ; Sanno, Rosendal, Aspan, Backhans, & Jacobson, ). Therefore, the dissemination of HEV and other diseases between wild boars and domestic pigs needs further investigation.…”