Bovine leptospirosis: the effects of vaccination on serological responses as determined by complement fixation and microscopic agglutination tests

Authors: Day AM, Hodges RT
Publication: New Zealand Veterinary Journal, Volume 35, Issue 5, pp 61-64, May 1987
Publisher: Taylor and Francis

Animal type: Cattle, Livestock, Production animal, Ruminant
Subject Terms: Animal remedies/veterinary medicines, Bacterial, Clinical pathology, Diagnostic procedures, Immune system/immunology, Zoonosis, Disease/defect, Infectious disease, Vaccination, Public health
Article class: Scientific Article

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Abstract: Fifty-one calves were divided into six trial groups of seven to eleven animals and vaccinated with a commercial leptospiral vaccine containing serovarspomona and hardjo. Vaccinations were given at 6,7,14 or 21 months of age and animals in various groups were vaccinated on one to four occasions. Antibody responses were determined by the microscopic agglutination test (MAT) and the complement fixation test (CFT) at one to four weeks intervals until 66 weeks after the start of the trial. Fifty percent or greater agglutination in serum diluted 1:100 or more and 50% or greater fixation of complement in serum diluted 1:20 or more were considered positive titres in the MAT or CFI respectively. Positive titres were still present in some animals six weeks after vaccination at 21 months of age. In other cases MAT titres (range 1:100-1:3000) persisted for 7-23 weeks and CFI titres (range 1:20-1540) persisted for 1-14 weeks. Marked individual variation in serological findings occurred using either test. In general the number of animals producing a positive titre, and the magnitude and persistence of titres was related to the number of doses of vaccine given. It was concluded that for dignostic purposes neither the CFT nor the MAT could reliably differentiate titres due to vaccination from those following natural infections.

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