Clinical Course of Infection and Cross-Species Detection of Equine Parvovirus-Hepatitis

Abstract

Since its first discovery by Arnold Theiler in 1918, serum hepatitis also known as Theiler’s disease has been reported worldwide, causing idiopathic acute hepatitis and liver failure in horses. Recent studies have suggested a novel parvovirus, named equine parvovirus hepatitis (EqPV-H), to be associated with Theiler’s disease. Despite the severity and potential fatality of EqPV-H infection, little is known about the possibility of developing chronic infections and putative cross-species infection of equine sister species. In the present longitudinal study, we employed qPCR analysis, serology, and biochemical testing as well as pathology examination of liver biopsies and sequence analysis to investigate potential chronic EqPV-H infection in an isolated study cohort of in total 124 horses from Germany over five years (2013–2018). Importantly, our data suggest that EqPV-H viremia can become chronic in infected horses that do not show biochemical and pathological signs of liver disease. Phylogenetic analysis by maximum likelihood model also confirms high sequence similarity and nucleotide conservation of the multidomain nuclear phosphoprotein NS1 sequences from equine serum samples collected between 2013–2018. Moreover, by examining human, zebra, and donkey sera for the presence of EqPV-H DNA and VP1 capsid protein antibodies, we found evidence for cross-species infection in donkey, but not to human and zebra. In conclusion, this study provides proof for the occurrence of persistent EqPV-H infection in asymptomatic horses and cross-species EqPV-H detection in donkeys.

Molecular Prevalence of Equine Parvovirus-Hepatitis in the Sera of Clinically Healthy Horses in South Korea

“…In 2018, Divers et al reported EqPV-H for the first time in a case of Theiler's disease (i.e., equine serum hepatitis or idiopathic acute hepatic disease) [6] in the United States [1]. Theiler's disease is the most frequent cause of acute and probably fatal viral equine hepatitis [7][8][9]. This disease has been linked to EqPV-H infection, with or without the previous administration of equine biological products [10][11][12][13].…”

First Clinical Case of Equine Parvovirus-Hepatitis-Related Theiler’s Disease in Asia

“…Recently, a study of the clinical course of EqPV-H described persistent infection of EqPV-H over five years that resulted in chronic viremia in subclinical horses [14]. Thus, it is plausible that the horse in our case may have been in a subclinical condition, showing chronic viremia, for some time.…”

“…However, we could not test for anti-EqPV-H antibodies because there are still few options for antibody detection in the field. In some of the previous papers dealing with EqPV-H [11,14], specific antibodies were measured using luciferase immunoprecipitation systems. However, there are no commercial kits for field testing.…”

“…The clinical significance of EqPV-H in liver diseases varies from subclinical to acute severe hepatitis and liver failure [2,4]. A recent study also revealed that persistent infection with EqPV-H over five years caused chronic viremia in subclinical horses [14]. In surveillance studies conducted on clinically healthy horses in the USA, China, Germany, Austria, and Brazil, the prevalence of EqPV-H DNA ranged from 7.1% to 17%, and the seroprevalence ranged from 15% to 34.7% [2,11,[15][16][17][18][19][20].…”

First Detection and Genetic Characterization of New Equine Parvovirus Species Circulating among Horses in Korea

“…Since the first isolation of the equine parvovirus in 1985, three equine parvovirus species (EqPVs), which belong to the genus Copiparvovirus and family Parvoviridae, were identified; namely, equine parvovirus-cerebrospinal fluid (EqPV-CSF, 2015), equine parvovirushepatitis (EqPV-H, 2018), and Eqcopivirus (EqCoPV, 2019) [1][2][3][4]. Except for EqPV-H, which is an etiologic agent for equine serum hepatitis [4][5][6][7][8][9][10][11][12][13][14][15], the other two species have not been well investigated.…”