Although pseudorabies virus can affect a wide range of mammalian and avian hosts, swine are the only natural hosts of the virus. The US commercial swine industry obtained pseudorabies-free status in 2004, which was important because of the economic value of domestic swine production; however, feral swine remain competent hosts and represent a constant threat for reintroducing the virus into the commercial industry. To better assess feral swine infection status, we collected 8,498 serum samples from feral swine across the United States between 1 October 2009 and 30 September 2012. Of these, 18% were antibody positive in 25 of 35 states where samples were collected, indicating that transmission risk is widespread.
Pedersen K, Bevins SN, Baroch JA, Cumbee JC Jr, Chandler SC, Woodruff BS, Bigelow TT, Deliberto TJ; Pseudorabies in Feral Swine in the United States, 2009-2012; J Wildl Dis. 2013 Jul;49(3):709-13. doi: 10.7589/2012-12-314.