Outbreak of equine herpesvirus type 1 myeloencephalitis: new insights from virus identification by PCR and the application of an EHV-1-specific antibody detection ELISA.
Five of 10 pregnant, lactating mares, each with a foal at foot, developed neurological disease. Three of them became recumbent, developed complications and were euthanased; of the two that survived, one aborted an equine herpesvirus type 1 (EHV-1)-positive fetus 68 days after the first signs were observed in the index case and the other gave birth to a healthy foal on day 283 but remained ataxic and incontinent. The diagnosis of EHV-1 myeloencephalitis was supported by postmortem findings, PCR identification of the virus and by serological tests with an EHV-1-specific ELISA. At the time of the index case, the 10 foals all had a heavy mucopurulent nasal discharge, and PCR and the ELISA were used to detect and monitor EHV-1 infection in them. The status of EHV-1 infection in the five in-contact mares was similarly monitored. Sera from three of the affected mares, taken seven days after the index case were negative or had borderline EHV-1-specific antibody titres. In later serum samples there was an increase in the titres of EHV-1-specific antibody in two of the affected mares. In contrast, sera from the five unaffected in-contact mares were all EHV-1-antibody positive when they were first tested seven or 13 days after the index case.
Centre for Equine Virology, School of Veterinary Science, University of Melbourne, Parkville 3010, Australia.
M J
MJ
Studdert
C A
CA
Hartley
K
K
Dynon
J R
JR
Sandy
R F
RF
Slocombe
J A
JA
Charles
M E
ME
Milne
A F
AF
Clarke
C
C
El-Hage
D000034:Abortion, Veterinary / Q000453:epidemiology; D000818:Animals; D000831:Animals, Newborn; D000914:Antibodies, Viral / Q000032:analysis* / Q000097:blood; D001259:Ataxia / Q000209:etiology / Q000662:veterinary; D004196:Disease Outbreaks / Q000662:veterinary*; D004679:Encephalomyelitis / Q000150:complications / Q000453:epidemiology / Q000662:veterinary*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D006566:Herpesviridae Infections / Q000150:complications / Q000453:epidemiology / Q000662:veterinary*; D004861:Herpesvirus 1, Equid / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D006734:Horse Diseases / Q000097:blood / Q000453:epidemiology* / Q000821:virology; D006736:Horses; D007150:Immunohistochemistry / Q000662:veterinary; D008297:Male; D016133:Polymerase Chain Reaction / Q000662:veterinary; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000453:epidemiology / Q000662:veterinary*; D014739:Victoria / Q000453:epidemiology
D000914:Antibodies, Viral