Prévalence des herpèsvirus équins en France au cours de l’année 2010

National audienceFive herpesviruses are currently known to be pathogenic to horses: equine herpesviruses 1, 3 and 4 (subfamily Alphaherpesvirinae) and equine herpesviruses 2 and 5 (subfamily Gammaherpesvirinae). Equine herpesvirus 1— one of the major infectious agents in horses—is responsible for three distinct clinical forms: respiratory, abortive and neurological. The other herpesviruses generally cause respiratory symptoms, in particular equine herpesvirus 4, the main agent of rhinopneumonitis. The multiplicity of clinical forms induced by the infection led the French network for epidemiological surveillance of equine diseases (RESPE) to include some of these viruses in its surveillance programme. Accordingly, herpesvirus 1 is closely monitored by the “neurological syndrome” sub-network whereas only herpesviruses 1 and 4 are screened for in the “abortion” and “acute respiratory syndrome” protocols. All the data collected were analysed to assess the incidence of these viruses throughout 2010. This analysis confirmed the major role played by herpesvirus 1 in both abortions and, more importantly, encephalomyelitis—particularly during a major animal epidemic in the Val d’Oise département. Herpesvirus 4 is mainly found in cases of acute respiratory syndrome.Cinq herpèsvirus sont connus à ce jour comme pathogènes chez le cheval : les herpèsvirus équins 1, 3 et 4 (sous-famille des Alphaherpesvirinae) et les herpèsvirus équins 2 et 5 (sousfamille des Gammaherpesvirinae). L’herpèsvirus équin 1, l’un des agents infectieux majeurs du cheval, est responsable de trois formes cliniques bien distinctes : une forme respiratoire, une forme abortive et une forme neurologique. Les autres herpèsvirus sont généralement responsables de symptômes respiratoires, notamment l’herpèsvirus équin 4, agent principal de la rhinopneumonie. La multiplicité des formes cliniques induites par l’infection a conduit le Réseau d’épidémiosurveillance en pathologie équine (RESPE) à inclure certains de ces virus à leur programme de surveillance. Ainsi, l’herpèsvirus 1 est particulièrement suivi par le sous-réseau appelé « syndrome neurologique », alors que seuls les herpèsvirus 1 et 4 sont recherchés dans les protocoles « avortement » et « syndrome respiratoire aigu ». L’ensemble des données collectées a ainsi pu être analysé pour permettre d’évaluer l’incidence de ces virus au cours de l’année 2010. Cette analyse a confirmé l’importance de l’herpèsvirus 1 dans les cas d’avortement, mais surtout lors d’encéphalomyélite et, notamment, lors d’une épizootie majeure survenue dans le Val-d’Oise. L’herpèsvirus 4 est surtout retrouvé dans les cas de syndrome respiratoire aigu

Les infections à herpesvirus équins 1 : quels enseignements tirés des dernières épizooties ?

International audienc

Myopathie atypique : les différentes sources d’intoxication. Comment gérer le risque ?

peer reviewe

Prévalence des herpèsvirus équins en France au cours de l’année 2010

National audienceFive herpesviruses are currently known to be pathogenic to horses: equine herpesviruses 1, 3 and 4 (subfamily Alphaherpesvirinae) and equine herpesviruses 2 and 5 (subfamily Gammaherpesvirinae). Equine herpesvirus 1— one of the major infectious agents in horses—is responsible for three distinct clinical forms: respiratory, abortive and neurological. The other herpesviruses generally cause respiratory symptoms, in particular equine herpesvirus 4, the main agent of rhinopneumonitis. The multiplicity of clinical forms induced by the infection led the French network for epidemiological surveillance of equine diseases (RESPE) to include some of these viruses in its surveillance programme. Accordingly, herpesvirus 1 is closely monitored by the “neurological syndrome” sub-network whereas only herpesviruses 1 and 4 are screened for in the “abortion” and “acute respiratory syndrome” protocols. All the data collected were analysed to assess the incidence of these viruses throughout 2010. This analysis confirmed the major role played by herpesvirus 1 in both abortions and, more importantly, encephalomyelitis—particularly during a major animal epidemic in the Val d’Oise département. Herpesvirus 4 is mainly found in cases of acute respiratory syndrome.Cinq herpèsvirus sont connus à ce jour comme pathogènes chez le cheval : les herpèsvirus équins 1, 3 et 4 (sous-famille des Alphaherpesvirinae) et les herpèsvirus équins 2 et 5 (sousfamille des Gammaherpesvirinae). L’herpèsvirus équin 1, l’un des agents infectieux majeurs du cheval, est responsable de trois formes cliniques bien distinctes : une forme respiratoire, une forme abortive et une forme neurologique. Les autres herpèsvirus sont généralement responsables de symptômes respiratoires, notamment l’herpèsvirus équin 4, agent principal de la rhinopneumonie. La multiplicité des formes cliniques induites par l’infection a conduit le Réseau d’épidémiosurveillance en pathologie équine (RESPE) à inclure certains de ces virus à leur programme de surveillance. Ainsi, l’herpèsvirus 1 est particulièrement suivi par le sous-réseau appelé « syndrome neurologique », alors que seuls les herpèsvirus 1 et 4 sont recherchés dans les protocoles « avortement » et « syndrome respiratoire aigu ». L’ensemble des données collectées a ainsi pu être analysé pour permettre d’évaluer l’incidence de ces virus au cours de l’année 2010. Cette analyse a confirmé l’importance de l’herpèsvirus 1 dans les cas d’avortement, mais surtout lors d’encéphalomyélite et, notamment, lors d’une épizootie majeure survenue dans le Val-d’Oise. L’herpèsvirus 4 est surtout retrouvé dans les cas de syndrome respiratoire aigu

Le parvovirus équin: un nouveau virus émergent au milieu de la triade hépatique

National audienc

In vitro evaluation of nine antiviral compounds for their potential effect against equid herpesvirus-4

International audienceBackground: Equid herpesvirus-4 (EHV-4) is a frequent respiratory pathogen of the horse. Occasional strains of EHV-4 sporadically induce abortion or neonatal death and although not clearly demonstrated, its involvement in neurological forms has been suggested. Despite prophylactic approaches using vaccines, resurgence of EHV-4 infection still constitutes an important threat to the horse industry. Yet very few studies have been conducted on the search for antiviral molecules against EHV-4 in vitro. Objectives: To assess the effectiveness of 9 antiviral compounds against EHV-4. Study design: In vitro experiment. Methods: Using Real-Time Cell Analysis (RTCA) of CCL26 cell line (African green monkey kidney) infected with EHV-4, 9 compounds with antiviral properties against EHV-1 were screened. CCL26 cells were infected with EHV-4 405/76 reference strain (VR2230) at a MOI 0.24 in the presence of 8 concentrations (50 to 0.39 μM) of each selected compound: aciclovir, ganciclovir, valganciclovir, decitabine, idoxuridine, pritelivir, cidofovir, aphidicolin and vidarabine. Formation of cytopathic effects was monitored by RTCA (xCELLigence and Incucyte®) and the viral load was quantified by qPCR. EC50 values for both xCELLigence and qPCR methods were determined. Results: EC50 values showed that seven molecules have an antiviral potency to prevent infection of CCL26 with EHV-4 in vitro. Aphidicolin was the most potent compound with an EC50 value of 1.63±0.76 μM measured by xCELLigence and 0.25±0.12 μM when measured by qPCR. Nucleoside analogs aciclovir and vidarabine were not efficient in preventing infection of CCL26 with EHV-4. Main limitation: Results need to be confirmed on different equine cell lines and with different EHV-4 strains isolated from the field. Conclusions: Seven antiviral compounds (ganciclovir, valganciclovir, decitabine, idoxuridine, pritelivir, cidofovir and aphidicolin) prevent EHV-4 cytopathic effect in CCL26 cells in vitro. Aciclovir, the most widely used antiviral in vivo against alpha-herpesviruses, does not appear to be effective against EHV-4 in vitro

Further Evidence for in Utero Transmission of Equine Hepacivirus to Foals

International audience(1) Background: Equine hepacivirus (EqHV), also referred to as non-primate hepacivirus (NPHV), infects horses—and dogs in some instances—and is closely related to hepatitis C virus (HCV) that has infected up to 3% of the world’s human population, causing an epidemic of liver cirrhosis and cancer. EqHV also chronically infects the liver of horses, but does not appear to cause serious liver damages. Previous studies have been looking to identify route(s) of EqHV transmission to and between horses. (2) Methods: In this retrospective study, we sought to evaluate the prevalence of vertical transmission taking place in utero with measuring by quantitative RT-PCR the amounts of EqHV genome in samples from 394 dead foals or fetuses, paired with the allantochorion whenever available. (3) Results: Detection of EqHV in three foals most likely resulted from a vertical transmission from the mares to the fetuses, consistent with the in utero transmission hypothesis. In support of this observation, the presence of EqHV genome was found for the first time in two of the allantochorions. (4) Conclusions: As seemingly benign viruses could turn deadly (e.g., Zika flavivirus) and EqHV happens to have infected a significant proportion of the world’s horse herds, EqHV infectious cycle should be further clarified