Abstract
AIM: To investigate the prevalence of Leptospira spp. and possible novel serovar Arborea infection in farmed deer in New Zealand. METHODS: In September 2006, five serum samples from a serum bank from each of 70 farms sampled for a previous national prevalence survey were forwarded to the World Health Organisation/Food and Agriculture Organisation/World Organisation for Animal Health (WHO/FAO/OIE) reference laboratory for leptospirosis in Brisbane, Australia, to test for reactivity to a reference panel of 23 serovars, most believed to be exotic to New Zealand, using the microscopic agglutination test (MAT). Eleven farms were seropositive for Arborea, a serovar novel to New Zealand. In July 2007, 126 additional banked serum samples from nine of those 11 farms (n=8–20/farm) were sent to the reference laboratory for similar serology. Two farms in the Southland region were considered positive for serovar Arborea. Tissue from deer kidneys (n=43) from these two farms collected at a deer slaughter premises (DSP) was cultured in November 2007 and November 2008. Sera from those deer were also sent to the laboratory in Brisbane. RESULTS: From the initial 350 sera, 96 (27.4%) and 19 (5.4%) samples were positive for Leptospira borgpetersenii serovar Hardjo-bovis and Leptospira interrogans serovar Pomona respectively. There were cross-reactions between serovar Hardjo-bovis with serovars Medanensis and Szwajizak. Serological evidence of serovars Tarassovi, Grippotyphosa, Celledoni, Australis, Zanoni, Robinsoni, Canicola, Kremastos, Bulgarica, Cynopteri, Ballum, Bataviae, Djasiman, Javanica, Panama, Shermani and Topaz was negative or sporadic, generally with titres of 1:50 and therefore likely non-specific. Fourteen (4.0%) samples from 11 farms were positive for serovar Arborea, justifying further investigation. The prevalence of serovar Arborea was 15% and 30% on two farms, from the 126 samples. None of 43 kidney and serum samples collected subsequently from those two farms were positive by culture or serology for serovar Arborea. CONCLUSIONS: While there were samples serologically positive for serovar Arborea in deer, attempts to isolate the organism were unsuccessful. The sample size for the follow-up investigation was insufficient to validate the presence or absence of infection, so further study should be undertaken to verify the status of this serovar of Leptospira spp. in New Zealand, in both deer and other livestock species.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.