Current status and future recommendations for feral swine disease surveillance in the United States

Abstract

USDA APHIS Wildlife Services (WS) responded to the threat of feral swine as a pathogen reservoir as early as 2004. To increase awareness and knowledge on that risk, WS began opportunistic sampling of animals harvested by its operational component to curtail swine damage to agriculture and property. Initially, pseudorabies and swine brucellosis were of most concern, as both serve as a potential threat to the domestic swine industry and the latter also possesses zoonotic implications. In 2006, classical swine fever, a foreign animal disease, became the main driver for feral swine pathogen surveillance. Subsequent years of surveillance identified numerous other disease risks inherent within populations of feral swine. Presently, feral swine surveillance falls under the purview of the APHIS National Feral Swine Damage Management Program, which began in 2014. In January 2018, a panel of animal disease experts representing industry, government, and academia were invited to Fort Collins, Colorado to discuss successes of this surveillance, identify any shortcomings or needs, and propose future feral swine surveillance. This manuscript serves to synthesize WS' surveillance and the future direction of these efforts.

Stability of classical swine fever virus and pseudorabies virus in animal feed ingredients exposed to transpacific shipping conditions

“…Pseudorabies virus (PRV) was officially eradicated from U.S. commercial swine in 2004, but remains a constant threat to commercial pork production due to the maintenance of the virus in U.S. feral swine (Brown et al, 2019;Pedersen et al, 2013) and the emergence of highly virulent strains in other countries. In 2011, a variant Chinese pseudorabies virus emerged on pig farms in China, characterized as having increased virulence in older grow-finish pigs and causing disease in swine previously vaccinated with Bartha-K61 (An et al, 2013;Wu, Bai, Sun, Chang, & Zhang, 2013).…”

Assessment of soy‐based imports into the United States and associated foreign animal disease status

“…ASFV and surrogates for FMDV and pseudorabies have been demonstrated to survive transboundary shipping in soy ingredients, such as soybean meal and soy oilcake (Dee et al., 2018 ). Pseudorabies has been eradicated from U.S. domestic swine herds, but is currently endemic in feral swine populations (Brown et al., 2019 ). This eradication was possible, in part, because of the availability of a vaccine for pseudorabies, and domestic swine herds can be vaccinated if pseudorabies is re‐introduced (Haagmans et al., 1999 ).…”

Detection error influences both temporal seroprevalence predictions and risk factors associations in wildlife disease models

“…Serum is collected from culled animals annually for serologic monitoring of diseases of importance for human and animal health. Sampling is distributed throughout the United States with samples being collected throughout the year (Brown et al, ). The serological data used in our study were collected from 33,794 wild pigs in 845 counties in the United States from January 2007 through July 2018 (Appendix ).…”

“…PRRS is an important cause of late-term reproductive losses, severe pneumonia, and increased mortality of domestic pigs with an estimated annual loss of $664 million to the US domestic swine industry (Holtkamp et al, 2013). IAVS can cause sporadic infections and pandemic outbreaks among humans and reduces the production of domestic swine (Ma, Kahn, & Richt, 2009 (Brown et al, 2019). The serological data used in our study were collected from 33,794 wild pigs in 845 counties in the United States from January 2007 through July 2018 (Appendix S1).…”