Fatal, generalized bovine herpesvirus type-1 infection associated with a modified-live infectious bovine rhinotracheitis parainfluenza-3 vaccine administered to neonatal calves.
Generalized bovine herpesvirus 1 (BHV-1) infection was diagnosed in six Salers calves from the same herd. The calves had received an intramuscular injection of modified-live infectious bovine rhinotracheitis parainfluenza-3 vaccine between birth and three days of age. The purpose of this study was to determine if the outbreak was associated with the vaccine strain of BHV-1. Analysis of epidemiological data and BHV-1 DNA for restriction fragment length polymorphism was undertaken. Multifocal necrosis in multiple organs was observed on pathological examination, and the presence of BHV-1 in tissues was confirmed by immunohistochemistry. Forty-three calves (aged birth to thirty days) were vaccinated over an 11-day interval. The 10 deaths recorded for vaccinated calves were clustered over a subsequent 14-day interval. Mortality in calves vaccinated between birth and three days of age was significantly higher than in nonvaccinated calves (chi-square test; p < or = 0.025), and this mortality was characterized by a greater age at death and duration of illness for vaccinated calves (t test; p < or = 0.001). The patterns of the restriction fragments, generated by six restriction endonucleases, of BHV-1 isolated from a necropsied calf and from the vaccine were identical, and different from that of a laboratory strain of BHV-1 (P8-2). These findings support the conclusion that newborn calves were susceptible to an intramuscularly injected vaccine strain of BHV-1, and that administration of an intramuscular modified-live infectious bovine rhinotracheitis parainfluenza-3 vaccine to neonatal calves may not be an innocuous procedure.
Bryan
L A
LA
Alberta Agriculture, Animal Industry Division, Airdrie Veterinary Laboratory.
Fenton
R A
RA
Misra
V
V
Haines
D M
DM
D000416:Alberta / Q000453:epidemiology; D000818:Animals; D000831:Animals, Newborn; D000956:Antigens, Viral / Q000032:analysis; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology*; D004196:Disease Outbreaks / Q000662:veterinary; D005260:Female; D006566:Herpesviridae Infections / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D007242:Herpesvirus 1, Bovine / Q000302:isolation & purification; D010224:Parainfluenza Virus 3, Human / Q000276:immunology*; D012141:Respiratory Tract Infections / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D014613:Vaccines, Attenuated / Q000009:adverse effects / Q000276:immunology; D014765:Viral Vaccines / Q000009:adverse effects* / Q000276:immunology
D000956:Antigens, Viral; D014613:Vaccines, Attenuated; D014765:Viral Vaccines