Dynamics of Virus Distribution in a Defined Swine Production Network Using Enteric Viruses as Molecular Markers

Abstract

Modern swine production systems represent complex and dynamic networks involving numerous stakeholders. For instance, livestock transporters carry live animals between fattening sites, abattoirs, and other premises on a daily basis. This interconnected system may increase the risk of microbial spread within and between networks, although little information is available in that regard. In the present study, a swine network composed of 10 finishing farms, one abattoir, and three types of stakeholders (veterinarians, livestock transporters, and nutritional technicians) in Quebec, Canada, was selected to investigate specific vectors and reservoirs of enteric viruses. Environmental samples were collected from the premises over a 12-month period. Samples were screened using targeted reverse transcription-PCR and sequencing of two selected viral markers, group A rotaviruses (RVA) and porcine astroviruses (PoAstV), both prevalent and genetically heterogeneous swine enteric viruses. The results revealed frequent contamination of farm sites (21.4 to 100%), livestock transporter vehicles (30.6 to 68.8%) and, most importantly, the abattoir yard (46.7 to 94.1%), depending on the sample types. Although high levels of strain diversity for both viruses were found, identical PoAstV and RVA strains were detected in specific samples from farms, the abattoir yard, and the livestock transporter vehicle, suggesting interconnections between these premises and transporters. Overall, the results from this study underscore the potential role of abattoirs and livestock transport as a reservoir and transmission route for enteric viruses within and between animal production networks, respectively. IMPORTANCE Using rotaviruses and astroviruses as markers of enteric contamination in a swine network has revealed the potential role of abattoirs and livestock transporters as a reservoir and vectors of enteric pathogens. The results from this study highlight the importance of tightening biosecurity measures. For instance, implementing sanitary vacancy between animal batches and emphasizing washing, disinfection, and drying procedures on farms and for transportation vehicles, as well as giving limited access and circulation of vehicles throughout the production premises, are some examples of measures that should be applied properly. The results also emphasize the need to closely monitor the dynamics of enteric contamination in the swine industry in order to better understand and potentially prevent the spread of infectious diseases. This is especially relevant when a virulent and economically damaging agent is involved, as seen with the recent introduction of the porcine epidemic diarrhea virus in the country.

Detection and Cellular Tropism of Porcine Astrovirus Type 3 on Breeding Farms

“…Porcine astroviruses (PoAstVs) are genetically diverse and are distributed worldwide [10] with five genetic lineages (PoAstV1-5), reflecting different origins, interspecies transmission and recombination events [9,11,12]. Globally, several studies have reported the molecular detection and genetic characterization of PoAstVs in various pig production systems in different countries including Canada [11,13], China [14,15,16], Croatia [17], Czech Republic [18], East Africa [19], Germany [20,21,22], Hungary [23], Italy [24], Japan [25], Slovakia [26], Sweden [27,28], South Korea [29], Thailand [30], and the United States [31,32,33,34,35,36,37]. However, the pathogenicity of a majority of PoAstVs is not well characterized with the exception of PoAstV3, which has been associated with polioencephalomyelitis in swine in both Europe [23] and the United States [31,32,33,34,35,36].…”

Dissemination of enteroviruses in the production chain of organic lettuce in Rio de Janeiro, Brazil

“…It was also observed that lettuces washed at the last stage of production do not represent a benefit for virus removal, since the waters used are also contaminated. Enteric viruses including EV have been used as indicators of sanitation and hygiene practices at food production sites on dairy and swine farms (Fongaro et al, 2014;Kokkinos et al, 2012;Lachapelle, Letellier, Fravalo, Brassard, & L'Homme, 2017;Maunula et al, 2013;Staggemeier et al, 2015;Yavarmanesh, Alum, & Abbaszadegan, 2015).…”

Scoping review on the epidemiology, diagnostics, and clinical significance of porcine astroviruses

“…Odds ratio (OR): a ratio for the measure of association between exposure and outcome (Suzmilas et al, 2010); OR = 1 cases has no effect on detection of PoAstVs, OR < 1 odds of detection of PoAstVs among cases are greater than odds of detection of PoAstVs among controls, OR > 1 odds of detection of PoAstVs among cases are lower than odds of detection of PoAstVs among controls. Boros et al, 2017 RT-PCR PRRSV, PCV2, PHEV, PPV 1,2,4 and PBoV Goecke et al, 2017 RT-PCR RVA, RVC, TGEV, PEDV, PRCV, PSaV, PEV, Parechovirus, Saffoldvirus, Lachapelle et al, 2017 RT-PCR RVA Xiao et al, 2017 RT-PCR TGEV, PRRSV, PEDV, CSFV Kumthip et al, 2018 RT-PCR RVA, RVC Matias et al, 2018 Sequencing PRRSV 1 and 2, PCV2, Suid alphaherpesvirus 1, PTV, PSV, APPV Salamunova et al, 2018 RT…”