Abstract
BackgroundBovine brucellosis is a zoonotic disease that causes substantial economic losses and has a strong impact on public health. The main objective of this paper is to determine the risk factors for new infections of Brucella abortus on Colombian cattle farms previously certified as being free of brucellosis. A case-control study was conducted by comparing 98 cases (farms certified as brucellosis-free for three or more years but became infected) with 93 controls (farms that remained brucellosis-free during at least the previous three years). The farms were matched by herd size and geographical location (municipality). Information was obtained via a questionnaire completed by veterinary officers through a personal interview with the herd owners.ResultsTwo-thirds of the herds (67%) were dairy herds, 16% were beef herds, and 17% were dual-purpose (beef and milk) herds. After exploratory univariate analysis, all explanatory variables with a p-value of ≤0.20 were included in a logistic regression model using the forward stepwise method to select the model with the best goodness of fit. The significant risk factors were the replacement of animals from farms not certified as brucellosis-free compared to replacement from certified brucellosis-free farms (OR = 4.84, p-value < 0.001) and beef cattle farms compared to dairy cattle farms (OR = 3.61, p-value = 0.017). When herds with and without artificial insemination were compared, it was observed that farms that used natural breeding with bulls from non-certified herds had a higher risk than farms using artificial insemination (OR = 2.45, p-value = 0.037), but when the bulls came from brucellosis-free farms, farms with natural breeding were less affected (OR = 0.30, p-value = 0.004) than farms using artificial insemination, whether with frozen semen from certified brucellosis-free herds or fresh semen from uncontrolled herds. The latter is commonly sold to neighbouring farms.ConclusionsThe government should make efforts to inform farmers about the risks involved in the introduction of semen and replacement heifers from farms that are not certified as brucellosis-free and to establish measures to control these practices.
Highlights
Introduction of infected animalsAdmittance of animals that have been in contact with seropositive animals in the originating farmTranshumance/pasture sharingContact with infected peopleContact with wild speciesArtificial insemination or embryo transferMovement of animals without official controlEndogenous origin of the new infection RecirculationMaintenance of animals diagnosed as positiveAbsence/deficiency of biosecurity on the farm not appreciate the benefits deriving from a brucellosisfree herd: The disease does not affect prices, and they do not understand the importance and the cost of reproductive disorders
The disease directly affects cattle and buffalo, which are the main reservoirs of B. abortus, other domestic and wild species can act as a reservoir [8, 9]
The aim of this study is to identify the risk factors associated with new infections of Brucella abortus detected between 2015 and 2016 on cattle farms previously certified as being free of the disease
Summary
Introduction of infected animalsAdmittance of animals that have been in contact with seropositive animals in the originating farmTranshumance/pasture sharingContact with infected peopleContact with wild speciesArtificial insemination or embryo transferMovement of animals without official controlEndogenous origin of the new infection RecirculationMaintenance of animals diagnosed as positiveAbsence/deficiency of biosecurity on the farm not appreciate the benefits deriving from a brucellosisfree herd: The disease does not affect prices, and they do not understand the importance and the cost of reproductive disorders. Animals are distributed over large, extensive grazing areas that are usually difficult to access, where the control measures are more difficult to apply, and the animals are prone to greater contact with uncontrolled contaminated sources. Dairy cattle producers are fully aware of the loss of production due to abortions and infertility and the subsequent important milk losses [20]. The main objective of this paper is to determine the risk factors for new infections of Brucella abortus on Colombian cattle farms previously certified as being free of brucellosis. Bovine brucellosis is a chronic, infectious disease caused by Brucella abortus, which has developed mechanisms to live intracellularly and is able to infect cattle for long. The main clinical signs are abortion, infertility, stillbirth or the birth of weak calves, along with epididymitis and orchitis in males [10, 11].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
