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.
