Seroprevalence of Leptospira Hardjo in the Irish suckler cattle population

Herds were categorised as either “Free from Infection” or “Infected” using the epidemiological software tool, FreeCalc 2.0. Using this classification, 237 herds were “Infected” (82.29%). The South West and South East regions had the highest herd prevalence. The regional effect on herd prevalence was largely mirrored by breeding herd size. A true animal-level prevalence of 41.75% was calculated using the epidemiological software tool, TruePrev. There was a statistically significant regional trend, with true prevalence being highest in the South East (P？<？0.05). The median Breeding Herd Size (BHS), when categorised into quartiles, had a statistically significant influence on individual animal true seroprevalence (P？<？0.001); true seroprevalence increased with increasing BHS.Leptospirosis is a widespread endemic disease in the Republic of Ireland. It is possible that economic losses due to leptospirosis in unvaccinated Irish suckler herds may be underestimated.