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Lateral transmission of equine arteritis virus among Lipizzaner stallions in South Africa
Author(s) -
GUTHRIE A. J.,
HOWELL P. G.,
HEDGES J. F.,
BOSMAN A.M.,
BALASURIYA U. B. R.,
McCOLLUM W. H.,
TIMONEY P. J.,
MacLACHLAN N. J.
Publication year - 2003
Publication title -
equine veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.82
H-Index - 87
eISSN - 2042-3306
pISSN - 0425-1644
DOI - 10.2746/042516403775467162
Subject(s) - biology , virology , semen , transmission (telecommunications) , virus , phylogenetic tree , serology , veterinary medicine , antibody , genetics , medicine , gene , electrical engineering , engineering
Summary Reasons for performing study :A serological study conducted in 1995 revealed that 7 stallions at the Lipizzaner Centre, Gauteng, South Africa, were seropositive for antibody to equine arteritis virus (EAV). A Lipizzaner stallion imported into South Africa from Yugoslavia in 1981 had previously (1988) been confirmed to be an EAV carrier. Despite being placed under life‐long breeding quarantine, EAV had been transmitted between stallions at the Lipizzaner Centre. Objectives : To investigate the phylogenetic relationships between the strain of EAV shed in the semen of the original carrier stallion and strains recovered from the semen of 5 other stallions; and to investigate the means whereby lateral transmission of EAV occurred among 7 in‐contact, nonbreeding stallions at the Centre. Methods : EAV was isolated from semen collected from the seropositive stallions using RK‐13 cells. Viral RNA was reverse transcribed and amplified by polymerase chain reaction using ORF5‐specific primers, subjected to sequence and phylogenetic analysis. Results : Phylogenetic analysis of strains of EAV recovered from the semen of 6 persistently infected stal lions confirmed that all viruses were closely related and probably derived from a common ancestor, i.e. the stallion imported from Yugoslavia. Lateral transmission subsequently occurred among 7 in‐contact, nonbreeding stallions at the Centre. It is speculated that these stallions may have been exposed to virus from be dding or fo mites contaminated with semen. Conclusions : These data confirm that lateral transmission of EAV can occur from shedding stallions to susceptible, in‐contact horses, including other stallions, which may become persistently infected with the virus. Potential relevance : The findings are consistent with lateral spread of a single, unique strain of EAV among a group; and suggest that transmission of EAV may be initiated by infection of one or more stallions with virus on bedding or other fomites contaminated with EAV‐infected semen.