Active equine parvovirus‐hepatitis infection is most frequently detected in Austrian horses of advanced age

Abstract

Background Equine parvovirus‐hepatitis (EqPV‐H) research is in its infancy. Information regarding prevalence, geographical distribution, genetic diversity, pathogenesis and risk factors enhances understanding of this potentially fatal infection. Objectives Determining the prevalence of EqPV‐H in Austrian equids. Investigating factors increasing probability of infection, liver‐associated biochemistry parameters, concurrent equine hepacivirus (EqHV) infection and phylogenetic analysis of Austrian EqPV‐H variants. Study design Cross‐sectional study. Methods Sera from 259 horses and 13 donkeys in Austria were analysed for anti‐EqPV‐H VP1‐specific antibodies by luciferase immunoprecipitation system (LIPS) and EqPV‐H DNA by nested polymerase chain reaction (PCR). Associations between infection status, sex and age were described. Glutamate dehydrogenase (GLDH), gamma‐glutamyl transferase (GGT), bile acids and albumin concentrations were compared between horses with active infection and PCR‐negative horses. PCR targeting partial EqPV‐H NS1 was performed and phylogenetic analysis of Austrian EqPV‐H variants was conducted. Complete coding sequences (CDS) of four Austrian variants were determined by next‐generation sequencing (NGS) and compared with published sequences. Results Horses' EqPV‐H seroprevalence was 30.1% and DNA prevalence was 8.9%. One horse was co‐infected with EqHV. Significantly, higher probability of active EqPV‐H infection was identified in 16‐ to 31‐year‐old horses, compared with 1‐ to 8‐year‐old horses (P = 0.002; OR = 8.19; 95% CI = 1.79 to 37.50) and 9‐ to 15‐year‐old horses (P = 0.03; OR = 2.96; 95% CI = 1.08 to 8.17). Liver‐associated plasma parameters were not significantly different between horses with active infection and controls. Austrian EqPV‐H variants revealed high similarity to sequences worldwide. No evidence of EqPV‐H was detected in donkeys. Main limitations Equids’ inclusion depended upon owner consent. There was only one sampling point per animal and the sample of donkeys was small. Conclusions EqPV‐H antibodies and DNA are frequently detected in Austrian horses, without associated hepatitis in horses with active infection. The risk of active EqPV‐H infection increases with increasing age. Phylogenetic evidence supports close relation of EqPV‐H variants globally, including Austrian variants.

Equine parvovirus hepatitis

“…Increasing age as a risk factor for EqPV-H infection was further supported by the findings of a surveillance study in Austrian horses. In this study the highest infection prevalence was found in 16to 31-year-old horses [33]. A recent study by Tomlinson et al reported EqPV-H in foals for the first time, with 79% (19/24) of foals that were EqPV-H PCR-negative at birth, becoming PCR-positive within their first year of life [21].…”

“…Recently, all 12 publicly available complete coding sequences (CDS) of the species Ungulate copiparvovirus 6 —obtained in China and the United States—were compared with the CDS of four Austrian variants and found to be closely related 33 . The genetic diversity of the NS and VP genes appears to be low among different EqPV‐H variants in the United States, China, Canada, New Zealand, Italy, and Germany, indicating high conservation and low genetic variability of variants circulating globally 16,25,32,35,37 .…”

Equine Parvovirus-Hepatitis Screening in Horses and Donkeys with Histopathologic Liver Abnormalities

“…In Europe, viral loads of 1.26 × 10 4 to 2.04 × 10 9 genome equivalents (GE)/million cells were detected in liver tissue of four horses suffering from Theiler’s disease [ 13 ]. In healthy horses in the USA, China, Germany and Austria a DNA prevalence for EqPV-H has been reported between 7% and 17% [ 8 , 14 , 15 , 16 , 17 , 18 ] compared to a markedly higher DNA prevalence between 54% and 79% in farms in the USA and Canada with recently documented cases of Theiler’s disease [ 10 , 12 , 19 ]. Current research is focused on disease outbreaks, possible transmission and seroprevalence in horse populations.…”

Circovirus in Blood of a Febrile Horse with Hepatitis

“…Real time PCR tests performed by Cornell University Animal Health Diagnostic Center reported negative results for the flavivirus equine hepacivirus and positive results for equine parvovirus (EqPV-H) with Ct values of 32.36. EqPV-H, a frequent equine infection [34,35], has been associated with and shown to induce hepatitis following inoculation although many EqPV-H infections are also asymptomatic [36][37][38].…”

“…Here a horse with a mild case of hepatitis was infected with a circovirus but also viremic at low levels (real time PCR Cut off 34) with the hepatotropic EqPV-H. Although many asymptomatic EqPV-H infections have been reported [34,35] EqPV-H detection in this horse does provides a conceivable explanation for its hepatitis [36,38]. Whether EqCV1 played a leading, supporting, or no role in this case of hepatitis or has the potential to cause other equine diseases will require further studies.…”