First report of Equine Parvovirus-Hepatitis (EqPV-H) in Argentina

Abstract

The novel Equine Parvovirus-Hepatitis (EqPV-H) was first identified in the serum and liver of a horse that died of equine serum hepatitis, also known as Theiler's disease. Several reports in recent years strongly suggest that EqPV-H is the etiologic agent of Theiler's disease. Brazil is the only South American country where infection with this virus has been reported. This study investigated the presence of EqPV-H DNA in horse serum pools (n=51), commercial horse serum batches (n=5) and individual serum samples from donor horses (n=175) from Argentina. All serum samples were analyzed by quantitative polymerase chain reaction (qPCR) and samples with positive or indeterminate results were further analyzed by NS1 nested-PCR for phylogenetic studies.

None of the serum pools was positive by qPCR but 9/51 pools were indeterminate (one or both test sample’s Ct values were higher than the limit of detection). The NS1 nested-PCR detected the EqPV-H DNA in 8 of these indeterminate samples (15.7 % of serum pools). Three of the commercial horse serum batches (60 %) contained EqPV-H DNA, detected either by qPCR and/or nested-PCR. From the 175 individual horse serum samples, three (1.71 %) were positive for EqPV-H by both techniques. The genetic analysis of the 12 partial NS1 sequences obtained showed that the local isolates were similar to EqPV-H sequences from Germany and China. This study provides the first evidence of the presence of EqPV-H in horses and in horse sera commercially available in Argentina and emphasizes the importance of controlling the biosecurity of commercial equine sera as well as any other blood-derived biological products of equine origin.