High Abundance and Genetic Variability of Atypical Porcine Pestivirus in Pigs from Europe and Asia

Abstract

Atypical porcine pestivirus (APPV) was recently reported to be associated with neurologic disorders in newborn piglets. Investigations of 1,460 serum samples of apparently healthy pigs from different parts of Europe and Asia demonstrate a geographically wide distribution of genetically highly variable APPV and high APPV genome and antibody detection rates.

An emerging novel virus: Atypical porcine pestivirus (APPV)

“…Moreover, it has been reported that detection rates of 2.4% to 22% for APPV genomes were found in apparently healthy pigs in the United States and Germany . In a recent similar study with serum samples from apparently healthy pigs, APPV prevalence reached from 2.3% to 17.5% in Europe and from 5% to 11% in China . All of the results demonstrated that APPV was highly prevalent in both apparently healthy pigs and CT‐affected pigs, suggesting the virus may have spread worldwide.…”

“…5,16,20 In a recent similar study with serum samples from apparently healthy pigs, APPV prevalence reached from 2.3% to 17.5% in Europe and from 5% to 11% in China. 21 All of the results demonstrated that APPV was highly prevalent in both apparently healthy pigs and CT-affected pigs, suggesting the virus may have spread worldwide. A most recent finding shows that presence of APPV genome in the serum samples of wild boars in Germany reached 19%, suggesting that the wild boars may be an important APPV reservoir.…”

“…Extensive efforts have been put into growing APPV on primary swine kidney cells and continuous swine kidney cell lines (PK15, IBRS, SK6, and ST), but all have failed . Recently, the results from three research groups demonstrated that APPV could be passaged on a few porcine cell lines, though the virus titers were low . Considering the high variability of APPV strains, it could not be excluded that some specific virus strains may be robust enough to be successfully cultured in vitro.…”

“…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.…”

“…5,9,15 Recently, the results from three research groups demonstrated that APPV could be passaged on a few porcine cell lines, though the virus titers were low. 12,16,21 Considering the high variability of APPV strains, it could not be excluded that some specific virus strains may be robust enough to be successfully cultured in vitro. Accordingly, it is worth investigating many more virus isolates in multiple cell lines for establishment of an APPV culture system.…”