The dilemma of rare events: Porcine epidemic diarrhea virus in North America

Abstract

Porcine epidemic diarrhea virus (PEDV) has been recognized as a swine pathogen for 40 years, but until 2013 had not been detected in the Western Hemisphere. From originally causing a relatively mild and sporadic disease, PEDV has been more recently associated with severe outbreaks of diarrheal disease in Asia, and subsequently North America. PEDV shares some important characteristics with two major pandemic viruses (porcine reproductive and respiratory virus; porcine circovirus type 2) of pigs that have high rates of mutation and high host specificity, and appear to have been present in the swine virome for decades prior to emerging to cause severe clinical disease. A unique feature of the PEDV in North America has been the implication of feed as a vehicle for transmission, with particular concerns related to ingredients of porcine origin. The importance of relatively rare events in contributing to both the emergence and transmission of PEDV is discussed in relation to approaches for managing the associated risks.

Effect of pelleting on survival of porcine epidemic diarrhea virus–contaminated feed

“…Currently, a bioassay is the best diagnostic method to measure infectivity. However, as explained by Davies (2015), the risk of an individual pig becoming infected is very low but carries a high collective risk. In the bioassay, pigs received only 10 mL of a sample compared with their normal feed consumptions.…”

Profile analysis of circRNAs induced by porcine endemic diarrhea virus infection in porcine intestinal epithelial cells

“…Porcine epidemic diarrhea (PED) is one of the enteric infectious diseases in pigs, characterized by severe enteritis, vomiting, watery diarrhea, and up to 90% death rate in piglets younger than one week old. Since its re-emergence in 2010, this disease has caused huge economic loss to the swine industry in North America and East Asia (Davies, 2015;Lee and Lee, 2014;Temeeyasen et al, 2014;Vlasova et al, 2014;Wang et al, 2016). Porcine epidemic diarrhea virus (PEDV), the causative agent of PED, is a single stranded, positive-sense enveloped RNA virus, belonging to the Alphacoronavirus genus within the Coronaviridae family.…”

El Niño Southern Oscillation (ENSO) and Health: An Overview for Climate and Health Researchers

“…Notwithstanding the complex pathways linking climate anomalies and diarrhoea [70] and the challenges this poses for quantifying the effects of weather and climate on water-associated diseases in general [71,72], diarrhoeal illness is generally sensitive to climate anomalies [74,75,76,77,78,79] with unusually warm conditions conducive to enhanced pathogen replication and survival rates while rainfall surpluses may transport faecal matter into water courses with micro-organisms becoming concentrated in water bodies during periods of rainfall deficit. While Demisse and Mengisitie [80] noted that El Niño has an impact on diarrhoea incidence for a number of major geographic regions, many of the cited papers address temperature/rainfall -diarrhoea association as opposed to climate driven variations in diarrhoea moderated by ENSO.…”