The Canadian 2014 porcine epidemic diarrhoea virus outbreak: Important risk factors that were not considered in the epidemiological investigation could change the conclusions

Abstract

The introduction and spread of porcine epidemic diarrhoea virus (PEDV) in North America resulted in significant death loss in the swine industry. As the industry learned how to manage this disease, many new risks were identified, including the potential for feed and feed ingredients to become contaminated and spread PEDV.In addition, biosecurity practices were reevaluated and strengthened throughout the industry. At the time of the outbreak epidemiologists did not understand, as well as they are understood today, all the risk factors that contribute to the spread of PEDV. As a result, the epidemiological investigations into the 2014 PEDV outbreak in eastern Canada may not have investigated all risk factors as thoroughly as they would be investigated today. In retrospect, many of the Bradford Hill criteria used to determine causation were not fulfilled. This review identifies risk factors that were not included in the 2014 epidemiology. If these risk factors were included in the epidemiology, the conclusions and determination of causation may have been different. K E Y W O R D SCanada, epidemiology, feed, feed ingredients, porcine epidemic diarrhoea virus, risk factors, spray-dried porcine plasmaThis is an open access article under the terms of the Creat ive Commo ns Attri bution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Quantifying the dynamics of pig movements improves targeted disease surveillance and control plans

“…Future studies are also needed to explore the contribution of movements to slaughterhouses, especially when pig is redirected to other slaughterhouses (i.e. slaughter not able to slaughter all animals) or send back to the farm of origin, this is very common in the US (Russell et al, 2020). Another limitation was the number of farms missing geographic locations, since this analysis will be re‐run be the local veterinary services yearly, once this farm location become available the results will be updated.…”

“…Future studies are also needed to explore the contribution of movements to slaughter houses, especially when pig are redirected to other slaughter houses (i.e., slaughter not able to slaughter all animals) or send back to the farm of origin, this is very common in the US, however little is known relevance in spreading disease back to the farm, however there is some early discussion about it (Russell et al, 2020).…”

Can we effectively manage parasites, prions, and pathogens in the global feed industry to achieve One Health?

“…However, the widespread use of SDPP has been compromised in the North American pork industry because a SDPP source contaminated with Porcine Epidemic Diarrhea Virus (PEDV) was implicated as the cause of the initial outbreak (Dee et al, 2014;Pasick et al, 2014;Pasma et al, 2016;Aubry et al, 2017;Perri et al, 2018). However, important risk factors were not considered in the epidemiological investigation of the 2014 Canadian PEDV outbreak, which makes this claim questionable (Russell et al, 2020). Furthermore, the lack of direct experimental evidence (Gerber et al, 2014), along with rigorous risk assessments that have shown that PEDV and other swine viruses are inactivated during processing SDPP (Sampedro et al, 2015), and the lack of causing an African Swine Fever Virus (ASFV) infection in naïve weaned pigs by feeding diets containing ASFV-contaminated liquid plasma (Blázquez et al, 2020), indicate that more thorough review of relative risks and benefits of using spray-dried animal plasma in swine feeds is warranted.…”

Regional Differences in and Influencing Factors of Animal Epidemic Risk in China

“…, 10 represent the parameters to be estimated, constant C is the drift term, and ε it is the random term. Several studies have discussed the risk factors associated with the prevalence of animal diseases, such as farm management practices (18), forest (19), soil water content (20), and water source (21). Evidence suggests that the spread of epidemic diseases is closely related to environmental factors, humans, and animals (22).…”