Presence of atypical porcine pestivirus (APPV) in Brazilian pigs

Abstract

Summary Recently, a putative new pestivirus species, provisionally named as Atypical Porcine Pestivirus (APPV), was associated with the congenital tremor in piglets in North America and consequently in Europe and Asia. The present research aimed to describe the detection and characterization of APPV employing NS5B gene partial sequencing, gross pathology and histologic examination of piglets displaying congenital tremor from two different farms of Southern Brazil. No gross lesions were observed, and the histological findings revealed moderate vacuolization of the white matter of the cerebellum. RT‐PCR followed by DNA sequencing and a phylogenetic analysis confirmed the presence of APPV in samples from the two farms, which the samples were distinct in nature. Phylogenetic reconstruction reinforced the high genetic variability within the APPVs previously reported. This is the first report of APPV in South America suggesting that this new group of viruses may be widespread in swine herds in other countries as it is in Brazil.

Viruses associated with congenital tremor and high lethality in piglets

“…To date, APPV has been identified in piglets from North American (Arruda et al., ), South American (Mósena et al., ), European (de Groof et al., ; Postel et al., ) and Asian (Yuan et al., ; Zhang et al., ) countries. To the best of the knowledge of the authors, this is the first report of simultaneous infections by APPV and PTV in symptomatic newborn piglets.…”

“…APPV was first described in 2015, after being identified in porcine serum samples, using next‐generation sequencing (NGS), but without any association with clinical signs (Hause et al., ). Thereafter, APPV infection with associated clinical manifestations was identified in piglets from Germany (Postel et al., ), Austria (Schwarz et al., ), China (Yuan et al., ; Zhang et al., ), Spain, the Netherlands (de Groof et al., ) and Brazil (Mósena et al., ). However, in all reports thus far, coinfections with other viral pathogens were not reported.…”

An emerging novel virus: Atypical porcine pestivirus (APPV)

“…Metagenomic sequencing is a powerful technique in identification of novel virus pathogens that has successfully been applied in discovering the APPV for the first time in the samples of swine in the United States . With availability of APPV genome sequence, a few RT‐PCR protocols that target conserved regions within NS3, NS4B, or NS5B have then been developed to detect the APPV and quantify the copies of virus genome in the clinical samples . Preferred specimens include brain, lymph node, and whole blood.…”

“…Of these, APPV was first identified by next‐generation sequencing from the samples in the United States in 2015 . Shortly thereafter, it was reported in pigs with CT in the United States, Germany, the Netherlands, Spain, Austria, China, and Brazil (Table ) …”

“…5 Shortly thereafter, it was reported in pigs with CT in the United States, Germany, the Netherlands, Spain, Austria, China, and Brazil (Table 1). 9,[11][12][13][15][16][17][18] The emergence of APPV, Bungowannah virus, and Linda virus in the pestivirus genus suggests that there are possibly more "atypical" pestiviruses circulating in domestic animals and wild animals that remain to be identified (Figure 1). Nevertheless, it has to be clarified here that the proposed term "atypical porcine pestivirus, APPV" is questionable because the "atypical" has already been used to name other new pestiviruses.…”