Risk factors of brucellosis (re-)incidence in sheep and goat flocks in an endemic area of Portugal
- 47 Downloads
This study aimed to determinate the main risk factors of brucellosis recurrence or highest animal incidence in flocks, under pastoralism, in an endemic area of Northeast Portugal. An epidemiological survey was performed on 25 recurrent (n = 18) or highest seropositive (n = 7) sheep and mixed goat flocks and 19 historical (≥ 10 years) brucellosis-free flock, between 2014 and 2017, within the same epidemiological area presenting an average annual incidence around 6%. According to the multivariable logistic model (P < 0.001), the lack of neighboring brucellosis-free flocks (odds ratio OR = 7.79; CI % 1.49–65.06), the occurrence of more than 50% of lambing or kidding in common paths and pastures (OR = 24.17; CI % 3.0–606.54), and the animal replacement with Rev.1 non-vaccinated young animals (OR = 18.47; CI % 2.54–408.21) were the causes that influence the recurrence and highest animal incidence in flocks. In extensive production systems, the confinement of the peri-parturient and the small ruminant replacement with Rev.1 vaccinated young females seems to play a major role on brucellosis control and eradication.
KeywordsBrucella melitensis Epidemiological survey Rev.1 vaccination Small ruminants
The authors thank Dr. Humberto Tavares, the supervisor veterinarian of the Livestock Producers Organization at Vinhais (Portugal), for the full access to data and flocks.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflicts of interests.
- Bamaiyi, P.H., Hassan, L., Khairani-Bejo, S., ZainalAbidin, M., Ramlan, M., Krishnan, N., Adzhar, A., Abdullah, N., Hamidah, N.H., Norsuhanna, M.M., Hashim, S.N., 2014. Case-control study on risk factors associated with Brucella melitensis in goat farms in Peninsular Malaysia. Tropical Animal Health and Production, 46(5):739–475.CrossRefGoogle Scholar
- Battistini M.L., Giovannini A., Tamba M., Caporale V., 1997. Application of a geographical information system to the epidemiological surveillance of notifiable diseases. Proceedings of the VIII° ISVEE, Paris, 1997. Epidémiologie Santé Animale, 31–32: 12.C.46.Google Scholar
- DGAV, 2016. Annex I.b: Programme for the eradication of bovine Tuberculosis, bovine Brucellosis or sheep and goat Brucellosis (B. melitensis) submitted for obtaining EU cofinancing. Available at: http://www.dgv.min-agricultura.pt, retrieved 21-3-2018.
- Hosmer, D.W. and Lemeshow, S., 1989. Applied logistic regression. New York, USA: WileyGoogle Scholar
- SAS Institute Inc., 2013. Using JMP 11. Cary, NC: SAS Institute Inc Cary.Google Scholar
- Thrusfield, M., 2005. Veterinary Epidemiology, 2nd Edition, (Blackwell Science, Oxford, UK).Google Scholar