Detection of Atypical Porcine Pestivirus in Piglets from Danish Sow Herds

Abstract

Atypical porcine pestivirus (APPV) was first discovered in North America in 2015 and was later shown to be associated with congenital tremor (CT) in piglets. CT is an occasional challenge in some Danish sow herds. Therefore, we initiated an observational case control study to clarify a possible relationship between CT and APPV in Danish pig production. Blood samples were collected from piglets affected by CT (n = 55) in ten different sow herds and from healthy piglets in five sow herds without a history of CT piglets (n = 25), as well as one sow herd with a sporadic occurrence of CT (n = 5). APPV was detected by RT-qPCR in all samples from piglets affected by CT and in three out of five samples from piglets in the herd with a sporadic occurrence of CT. In the herds without a history of CT, only one out of 25 piglets were positive for APPV. In addition, farmers or veterinarians in CT-affected herds were asked about their experience of the issue. CT is most often seen in gilt litters, and a substantial increase in pre-weaning mortality is only observed in severe cases. According to our investigations, APPV is a common finding in piglets suffering from CT in Denmark.

Development of a Crystal Digital RT-PCR for the Detection of Atypical Porcine Pestivirus

“…APPV is a newly discovered swine pathogen, which has been reported in many countries [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 ]. Some provinces in China have reported this disease since it was discovered in the USA in 2015 [ 12 , 13 , 14 , 15 , 16 , 17 ].…”

“…APPV was first found in domestic pigs in the United States of America (USA) in 2015 [ 2 ], and then identified to be associated with the clinical piglets with congenital tremor (CT) in 2016 [ 3 ]. Subsequently, APPV was reported in many countries, such as China, Germany, Italy, Great Britain, Austria, Switzerland, Spain, Hungary, Brazil, Danmark, and Japan [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 ]. Guangdong was the first Chinese province to report APPV in 2016 [ 4 ], followed by its discovery in Guangxi, Yunnan, Guizhou, Anhui, Jiangxi, Henan, and other provinces [ 12 , 13 , 14 , 15 , 16 , 17 ].…”

An outbreak of splayleg and congenital tremors in piglets farrowed by a newly populated sow herd

“…10 In Denmark, no reports of concomitant SL were mentioned in 10 herds with CT problems where all affected piglets tested (55) were found to be PK positive. 11 What is currently known seems to suggest that there are situations where PK infection may be associated with SL problems, but not necessarily in others. Differences between PK strains have been identified.…”

Detection and localization of atypical porcine pestivirus in the testicles of naturally infected, congenital tremor affected piglets

“…APPV was discovered in the United States in 2015, by metagenomic sequencing of a sample, which was real‐time quantitative reverse transcription PCR (qRT‐PCR) positive for porcine reproductive and respiratory syndrome virus (PRRSV) (Hause et al., 2015). To date, APPV has been identified in Germany (Beer et al., 2017; Postel et al., 2016), Sweden (Blomström et al., 2016), the Netherlands (de Groof et al., 2016), Austria (Schwarz et al., 2017), Spain (Muñoz‐González et al., 2017), China (Yuan et al., 2017), Great Britain, Italy (Postel et al., 2017), Brazil (Gatto, Harmon, et al., 2018), Hungary (Dénes et al., 2018), Canada (Dessureault et al., 2018), Switzerland (Kaufmann et al., 2019), Japan (Kasahara‐kamiie et al., 2021) and most recently in Denmark (Pedersen et al., 2021). APPV was also detected in wild boars in Germany and Serbia (Cagatay et al., 2018), suggesting that, similar to classical swine fever, wild boars may serve as a virus reservoir (Vilček & Nettleton, 2006).…”