Molecular Surveillance of EHV-1 Strains Circulating in France during and after the Major 2009 Outbreak in Normandy Involving Respiratory Infection, Neurological Disorder, and Abortion.

Sutton G1,2, Garvey M3, Cullinane A4, Jourdan M5, Fortier C6,7, Moreau P8, Foursin M9, Gryspeerdt A10, Maisonnier V11, Marcillaud-Pitel C12, Legrand L13,14, Paillot R15,16, Pronost S17,18.

Author information

1: LABÉO Frank Duncombe, 14280 Saint-Contest, France. gabrielle.sutton@laboratoire-labeo.fr.
2: NORMANDIE UNIV, UNICAEN, BIOTARGEN, 14000 Caen, France. gabrielle.sutton@laboratoire-labeo.fr.
3: Irish Equine Centre, Johnstown, Naas, County Kildare, W91 RH93, Ireland. MGarvey@irishequinecentre.ie.
4: Irish Equine Centre, Johnstown, Naas, County Kildare, W91 RH93, Ireland. ACullinane@irishequinecentre.ie.
5: RESPE, 14280 Saint-Contest, France. technicien@respe.net.
6: LABÉO Frank Duncombe, 14280 Saint-Contest, France. christine.fortier@laboratoire-labeo.fr.
7: NORMANDIE UNIV, UNICAEN, BIOTARGEN, 14000 Caen, France. christine.fortier@laboratoire-labeo.fr.
8: Clinique équine de la Boisrie, 61500, Chailloué, France. peg_moreau@yahoo.fr.
9: Clinique équine de la Boisrie, 61500, Chailloué, France. clin.eq.laboisrie@laposte.net.
10: Equi Focus Point Belgium, 8900 Ypres, Belgium. loic.legrand@laboratoire-labeo.fr.
11: RESPE, 14280 Saint-Contest, France. contact@respe.net.
12: RESPE, 14280 Saint-Contest, France. romain.paillot@laboratoire-labeo.fr.
13: LABÉO Frank Duncombe, 14280 Saint-Contest, France. stephane.pronost@laboratoire-labeo.fr.
14: NORMANDIE UNIV, UNICAEN, BIOTARGEN, 14000 Caen, France. stephane.pronost@laboratoire-labeo.fr.
15: LABÉO Frank Duncombe, 14280 Saint-Contest, France. c.marcillaud-pitel@respe.net.
16: NORMANDIE UNIV, UNICAEN, BIOTARGEN, 14000 Caen, France. c.marcillaud-pitel@respe.net.
17: LABÉO Frank Duncombe, 14280 Saint-Contest, France. annick.gryspeerdt@gmail.com.
18: NORMANDIE UNIV, UNICAEN, BIOTARGEN, 14000 Caen, France. annick.gryspeerdt@gmail.com.

Abstract

Equine herpesvirus 1 (EHV-1) is an Alphaherpesvirus infecting not only horses but also other equid and non-equid mammals. It can cause respiratory distress, stillbirth and neonatal death, abortion, and neurological disease. The different forms of disease induced by EHV-1 infection can have dramatic consequences on the equine industry, and thus the virus represents a great challenge for the equine and scientific community. This report describes the progress of a major EHV-1 outbreak that took place in Normandy in 2009, during which the three forms of disease were observed. A collection of EHV-1 strains isolated in France and Belgium from 2012 to 2018 were subsequently genetically analysed in order to characterise EHV-1 strain circulation. The open reading frame 30 (ORF30) non-neuropathogenic associated mutation A2254 was the most represented among 148 samples analysed in this study. ORF30 was also sequenced for 14 strains and compared to previously published sequences. Finally, a more global phylogenetic approach was performed based on a recently described Multilocus Sequence Typing (MLST) method. French and Belgian strains were clustered with known strains isolated in United Kingdom and Ireland, with no correlation between the phylogeny and the time of collection or location. This new MLST approach could be a tool to help understand epidemics in stud farms.