Prevalence of antibodies to Leptospira interrogans serovar hardjo in bulk tank milk from unvaccinated irish dairy herds
1 Faculty of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland
2 Teagasc, Dairy Production Research Centre, Moorepark, Fermoy, Co Cork, Ireland
3 Faculty of Agriculture, University College Dublin, Belfield, Dublin 4, Ireland
4 Veterinary Sciences Division, Stoney Road, Belfast, BT4 3SD, Northern Ireland
Irish Veterinary Journal 2004, 57:226-231 doi:10.1186/2046-0481-57-4-226Published: 1 April 2004
Bulk tank milk samples, collected from 347 herds throughout the Republic of Ireland using a sampling frame based on seven milk-recording organisations, were tested by ELISA for antibodies to Leptospira interrogans serovar hardjo. These herds, which had not been vaccinated against leptospirosis within the previous five years, were categorised according to their province, milk-recording organisation and size. Two-hundred-and-seventy-three herds (79%) had a positive ELISA titre. Both the probability of a herd being seropositive and the antibody level in the herd milk sample were affected by the province (P < 0.05 and P < 0.01, respectively) and the herd size category (P < 0.05 and P < 0.01, respectively). Larger herds were significantly more likely to have positive reactions and higher mean concentrations of antibody. It was concluded that a high proportion of unvaccinated Irish dairy herds have been exposed to infection with Leptospira hardjo.