Spillover of Swine Coronaviruses, United States

Abstract

Porcine epidemic diarrhea virus, a pathogen first detected in US domestic swine in 2013, has rapidly spilled over into feral swine populations. A better understanding of the factors associated with pathogen emergence is needed to better manage, and ultimately prevent, future spillover events from domestic to nondomestic animals.

Emerging and re-emerging coronaviruses in pigs

“…Additionally, PEDV infects cells from pigs, humans, monkeys, duck, and bats, further supporting the theory that PEDV had crossed the batswine interspecies barrier sometime in the past (Table 1) [48,49]. PEDV has been detected from feral pigs in Korea and the US [50,51 ], with the latter study suggesting that PEDV may have spilled over from domestic to feral pigs. However, because there are no control measures to prevent PEDV circulation in feral pigs, they may represent a PEDV reservoir that can lead to PEDV outbreaks in the future.…”

A retrospective study of porcine epidemic diarrhoea virus (PEDV) reveals the presence of swine enteric coronavirus (SeCoV) since 1993 and the recent introduction of a recombinant PEDV‐SeCoV in Spain

“…In the Americas, PEDV was first detected in 2013 in the USA (Stevenson et al, 2013) and spread rapidly through the country, as well as to other countries in North, Centre and South America (Barrera et al, 2017;Jarvis, Lam, Rovira, & Marthaler, 2016;Lara-Romero et al, 2018;Pasick et al, 2014). Infection resulted in high mortality in piglets (up to 90%-95%) and caused huge economic losses to the pig industry (Bevins et al, 2018). After PEDV emergence in the USA, outbreaks have been reported in several European countries such as Germany (Stadler et al, 2015), Ukraine (Dastjerdi, Carr, Ellis, Steinbach, & Williamson, 2015), the Netherlands (Dortmans et al, 2018), France (Grasland et al, 2015),…”

A framework for surveillance of emerging pathogens at the human-animal interface: Pigs and coronaviruses as a case study

“…Of the alpha-CoVs, the same genus as Middle Eastern respiratory syndrome CoV (MERS-CoV), the three most commonly studied and monitored alpha-CoVs in pigs are transmissible gastroenteritis virus (TGEV), porcine respiratory CoV (PRCV), and porcine epidemic diarrhea virus (PEDV). These viruses are highly prevalent and transmissible in domestic pigs ( Li et al, 2018 ; Wang et al, 2019 ) and wild pigs ( Kaden et al, 2009 ; Roic et al, 2012 ; Lee et al, 2016 ; Bevins et al, 2018 ), although surveys in wild pigs remain scarce. Additionally, a severe acute respiratory syndrome CoV (SARS-CoV)-like alpha-CoV named swine acute diarrhea syndrome-coronavirus (SADS-CoV) and porcine enteric alpha-CoV (PEAV) have recently emerged in pigs (causing widespread morbidity and mortality) likely through spillover from bats ( Gong et al, 2017 ; Wang et al, 2018 ; Zhou et al, 2018 ).…”

“… Risk factor Type Rationale Scale Source Caveats Pathogen availability in hosts ( A ) Host density A Pathogen availability – all host species Host density affects dynamics and prevalence of CoVs in each host population County (All data streams) ( Lewis et al, 2017 ) using methods from ( Lewis et al, 2019 ) ( USDA, 2020 ) ( Institute, 2018 ) Wild pigs: density over time is important because densities can fluctuate dramatically due to birth pulses and control efforts. Commercial domestic pigs: Size of farms may not correlate directly to risk due to differences in farm connectivity and biosecurity CoV trends in hosts A Pathogen availability – all host species Historical trends of CoV circulation in hosts could represent hotspots for CoV availability in hosts County (All data streams) ( USDA-APHIS, 2015 ; Bevins et al, 2018 ; Benatia et al, 2020 ) Recent prevalence of specific ‘high-risk’ CoVs would be a more direct risk metric of pathogen availability Climate A Pathogen availability – all host species CoV transmission within host species will be higher in colder climates because CoVs persist longer outside hosts in colder climates providing an additional source of infection within host species (i.e., higher virus availability). County nCLIMGRID ( Vose et al, 2014 ) Relationship of climate and CoV prevalence remains poorly understood, is likely non-linear, and depends on other factors that could modify its effects.…”