Prevalence of antibodies to Leptospira serovars in beef cattle in central Queensland

Objective To obtain up-to-date data on the prevalence of antibodies to Lept ospira serovars in central Queensland beef herds preliminary to assessing t heir role in bovine subfertility and the role of cattle as a zoonotic reser voir. Design Sera from 2857 female cattle in 68 central Queensland beef herds wer e tested for antibodies to 14 Leptospira serovars using the microscopic agg lutination test. Vaccination use and age of cattle were collected to enable the calculation of crude and age-stratified seroprevalences. Results The most commonly detected antibodies were to serovars hardjo (15.8 % crude seroprevalence), tarassovi (13.9%), pomona (4.0%) and szwajizak (2. 2%). Vaccinates were omitted from the hardjo and pomona seroprevalence data . The seroprevalence for hardjo and pomona tended to increase with age of t he animals. Conclusion These results are broadly similar to those of previous serologic al surveys. The data suggest that serovars other than hardjo, pomona and ta rassovi, are unlikely to have a significant role in bovine subfertility and that cattle are unlikely to be a source of human infection with them in ce ntral Queensland.