Flock-level risk factors associated with leptospirosis in dairy goats in a semiarid region of Northeastern Brazil

Abstract

A cross-sectional study based on a planned sampling was carried out to determine flock-level risk factors associated to Leptospira spp. infection in dairy goat flocks in a semiarid region of Northeastern Brazil. Serum samples from 975 adult dairy goats from 110 flocks were examined for Leptospira spp. antibodies by MAT using 24 serovars. A structured questionnaire focusing on risk factors for leptospirosis was completed for each flock. Of the 110 flocks 48 (43.6%; 95% CI: 34.2–53.4%) presented at least one seropositive animal, and most frequent serovar was Autumnalis (10.9%). Ninety-eight (8.7%; 95% CI: 5.7–12.9%; design effect=4.23) of the 975 goats tested seropositive at MAT, and serovar Autumnalis was also the most frequent (1.74%). Presence of rodents (OR=2.78; P=0.015) was identified as a risk factor. There was also association between history of infertility (OR=14.74; P=0.015) and prevalence of positive flocks. We suggest that a program of rodent control should be included in the flock management practices aiming to reduce transmission of the agent and then to reduce prevalence of positive flocks and occurrence of reproductive disorders such as impaired fertility.