Molecular investigations on the prevalence and viral load of enteric viruses in pigs from five European countries

Abstract

Enteric viral infections in pigs may cause diarrhea resulting in ill-thrift and substantial economic losses. This study reports the enteric infections with porcine astrovirus type 4 (PAstV4), porcine group A rotavirus (GARV), porcine group C rotavirus (GCRV), porcine circovirus type 2 (PCV2) and porcine kobuvirus (PKoV) in 419 pigs, comprising both healthy and diarrheic animals, from 49 farms in five European countries (Austria, Germany, Hungary, Spain and Sweden). Real-time RT-PCR assays were developed to test fecal samples and to compare the prevalence and viral load in relation to health status, farms of origin and age groups. The results showed that PAstV4 (70.4%) was the dominant virus species, followed by PKoV (56.7%), PCV2 (42.2%), GCRV (3%) and GARV (0.9%). Diarrheic pigs had a higher viral load of PAstV4 in the nursery and growing-finishing groups. Rotaviruses were mainly detected in diarrheic pigs, whereas PCV2 was more often detected in clinically healthy than in diarrheic pigs, suggesting that most PCV2 infections were subclinical. PAstV4, PCV2 and PKoV were considered ubiquitous in the European pig livestock and co-infections among them were frequent, independently of the disease status, in contrast to a low prevalence of classical rotavirus infections.

Study of porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) frequencies and coinfection in mexican farrow to finish pig farms

“…PCV2 frequencies reported over last (Sun et al, 2015), while another work, in Japan found 80% of positive tonsil samples collected from pigs aged 6 months (Saekhow et al, 2015). Our results showed that PCV2 was detected in all states, with a frequency of 57% of positive herds, and 49% of positive animals, in five European countries 42% of fecal samples taken from both healthy and diarrheic pigs were positive and the percentage was higher in healthy compared to diseased animals (Zhou et al, 2016), which suggest that most PCV2 infections were subclinical. In our study only samples from diseased animals were included; it could produce very interesting results to include also healthy animals to determine total and subclinical frequencies.…”

Detection of a novel circovirus PCV3 in pigs with cardiac and multi-systemic inflammation

“…A possible pathogenic role for PAstV4 is therefore also conceivable alone or in concert with PCV3. PAstV4, first sequenced in Hungarian pig feces in 2011 [32], are a diverse group of related viruses that can be detected in the feces of 70 % of European pigs tested with higher viral loads in some age groups of diarrheic pigs [33] and may be associated with diarrhea in pigs from Minnesota [34]. PAstV4 was also detected in the blood of healthy pigs from Croatia [35].…”

A novel porcine kobuvirus emerged in piglets with severe diarrhoea in China

“…Some studies showed PKV had significantly higher prevalence in diarrhoeic pigs than healthy pigs in Hungary, Spain, South Korea, China and Brazil (Barry, Ribeiro, Alfieri, van der Poel, & Alfieri, ; Park et al., ; Wang, Lan, & Hua, ; Zhou et al., ). Several studies suggested that there was no significance in the incidence of PKV among pigs with diarrhoea and healthy pigs in Slovakia, Austria and USA (Jackova et al., ; Verma, Mor, Abdel‐Glil, & Goyal, ; Zhou et al., ). Even more surprising is that PKV had significantly higher prevalence in healthy pigs than diarrhoeic pigs in Sweden and South Korea (An et al., ; Zhou et al., ).…”

“…Several studies suggested that there was no significance in the incidence of PKV among pigs with diarrhoea and healthy pigs in Slovakia, Austria and USA (Jackova et al., ; Verma, Mor, Abdel‐Glil, & Goyal, ; Zhou et al., ). Even more surprising is that PKV had significantly higher prevalence in healthy pigs than diarrhoeic pigs in Sweden and South Korea (An et al., ; Zhou et al., ). In addition, PKV co‐infected by porcine epidemic diarrhoea virus, porcine transmissible gastroenteritis virus, porcine astrovirus, porcine rotavirus A, porcine circovirus type 2 was reported in several studies (Dufkova, Scigalkova, Moutelikova, Malenovska, & Prodelalova, ; Jackova et al., ; Park et al., ; Reuter et al., ; Verma et al., ; Zhou et al., ).…”

“…To confirm the cause of the diarrhoea, eight commercial kits were used to test the presence of porcine common diarrhoea‐associated pathogens (including porcine circovirus type 2, pseudorabies virus, classical swine fever virus, porcine epidemic diarrhoea virus, porcine transmissible gastroenteritis virus, porcine rotavirus, pathogenic Escherichia coli and Salmonella ). In addition, four novel porcine diarrhoea‐related viruses (including PKV, porcine astrovirus, porcine deltacoronavirus and porcine bocavirus) were further tested according to previously published PCR protocols (Zhai et al., ; Zheng et al., ; Zhou et al., ).…”