Detection of Pseudorabies Virus in Wild Boar Foetus

Simple Summary Pseudorabies virus (PRV) is a worldwide pathogen primarily affecting domestic and wild swine. In wild boar, seroprevalence rates are high, but little information is available about the impact of the disease on reproduction in this wild species. Our aim s to investigate the presence of Pseudorabies virus in foetus samples collected from pregnant animals living in an endemic area. A polymerase chain reaction (PCR) positive foetus sample is identified from a seropositive and viral shedding sow. Sequence analysis confirms the molecular result, describing for the first time the viral presence in wild boar foetus, suggesting an additional transmission route. Pseudorabies, or Aujeszky's disease, is a notifiable worldwide infection of domestic and feral swine that causes economic losses for the swine industry. In domestic pigs, the virus is responsible for nervous and/or respiratory symptoms; in pregnant sows, it is one of the major causes of stillbirth, mummification, embryonic death, and infertility (SMEDI). It is known that PRV infection in wild boar is associated with low pathogenicity and attenuated or absent symptomatology, but limited information is available about the ability of the virus to infect the foetuses of infected wild boar pregnant sows. Due to scarce information about the reproductive consequences, we investigate the possible intrauterine vertical transmission of the virus in wild boar pregnant sow living in a highly infected area. A number of 54 hunted wild boar were sampled during 2018-2019, and blood, genital and nasal swabs, placenta, and fetuses were collected for serological and molecular investigations. A seroprevalence of 74% (40/54) was detected, while 1/24 pregnant sow and 1/24 pooled foetuses tested positive by PCR (gene gB). This is the first evidence of viral detection in foetuses from seropositive pregnant wild boar. This finding suggests the possible pathogenetic role of PRV on pregnancy in wild boar and the existence of an additional transmission route.