Semina: Ciências Agrárias (Nov 2016)

Prevalence and herd-level risk factors of bovine tuberculosis in the State of Goiás, Brazil

  • Willian Vilela Rocha,
  • Valéria de Sá Jayme,
  • Ana Lourdes Arrais de Alencar Mota,
  • Wilia Marta Elsner Diederichsen de Brito,
  • Glauciane Ribeiro de Castro Pires,
  • José Soares Ferreira Neto,
  • José Henrique Hildebrand Grisi-Filho,
  • Ricardo Augusto Dias,
  • Marcos Amaku,
  • Evelise Oliveira Telles,
  • Fernando Ferreira,
  • Marcos Bryan Heinemann,
  • Vítor Salvador Picão Gonçalves

DOI
https://doi.org/10.5433/1679-0359.2016v37n5Supl2p3625
Journal volume & issue
Vol. 37, no. 5Supl2
pp. 3625 – 3638

Abstract

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Bovine tuberculosis results in economic losses in livestock production and poses a risk to public health. This study aimed to characterize the epidemiological status of bovine tuberculosis in adult cows in the state of Goiás, Brazil. The state was divided into three sampling strata, corresponding to different livestock production circuits. A total of 18,659 animals were tested with the comparative cervical tuberculin test (CCT), in 300 randomly sampled bovine herds per stratum. An epidemiological questionnaire was used to identify health and management practices that may be associated with the presence of tuberculosis infection in the herd. In Stratum 1, dominated by beef cattle, no animals reacted to the CCT. In Stratum 2, which covers the main dairy regions of the state, the prevalence was estimated at 8.67% [5.73 to 12.74%] for herds and at 0.9% [0.21 to 1.58%] for animals. In Stratum 3, characterized by a mix of dairy, beef and dual-purpose herds, the prevalence was estimated at 1.00% [0.21 to 2.89] for herds and 0.30% [0.10 to 0.49 %] for animals. The overall prevalence in the state of Goiás was 3.43% [2.20 to 4.67%] for herds and 0.30% [0.10 to 0.49%] for animals. The multiple logistic regression analysis revealed that herd-level risk factors associated with the presence of the bovine tuberculosis are: the location of the herd in Stratum 2 (OR = 12.05 [3.52 to 41.28]) and the number of times a cow is milked per day (OR = 6.27 [2.72 to 14.44]). Regular veterinary care was identified as a protective factor (OR = 0.38 [0.15-0.94]). These results indicate that bovine tuberculosis is endemic in the state; its spatial distribution is heterogeneous with a strong concentration in dairy regions. The most intensive dairy farms are those with the highest risk, which is consistent with what other authors’ found elsewhere in Brazil. The epidemiological information generated by this study provides information for planning of risk-based surveillance actions, and justifies the adoption of free-herd certification programs for bovine tuberculosis in the main dairy regions of Goiás.

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