Epidemiological investigation of bovine tuberculosis herd breakdowns in Spain 2009/2011
PLoS ONE publica este artículo de investigación
15 de agosto de 2014
We analyzed the most likely cause of 687 bovine tuberculosis (bTB) breakdowns detected in Spain between 2009 and 2011 (i.e., 22% of the total number of breakdowns detected during this period). Seven possible causes were considered: i) residual infection; ii) introduction of infected cattle from other herds; iii) sharing of pastures with infected herds; iv) contiguous spread from infected neighbor herds; v) presence of infected goats in the farm; vi) interaction with wildlife reservoirs and vii) contact with an infected human. For each possible cause a decision tree was developed and key questions were included in each of them. Answers to these key questions lead to different events within each decision tree. In order to assess the likelihood of occurrence of the different events a qualitative risk assessment approach was used. For this purpose, an expert opinion workshop was organized and ordinal values, ranging from 0 to 9 (i.e., null to very high likelihood of occurrence) were assigned. The analysis identified residual infection as the most frequent cause of bTB breakdowns (22.3%; 95%CI: 19.4-25.6), followed by interaction with wildlife reservoirs (13.1%; 95%CI: 10.8-15.8). The introduction of infected cattle, sharing of pastures and contiguous spread from infected neighbour herds were also identified as relevant causes. In 41.6% (95%CI: 38.0-45.4) of the breakdowns the origin of infection remained unknown. Veterinary officers conducting bTB breakdown investigations have to state their opinion about the possible cause of each breakdown. Comparison between the results of our analysis and the opinion from veterinary officers revealed a slight concordance. This slight agreement might reflect a lack of harmonized criteria to assess the most likely cause of bTB breakdowns as well as different perceptions about the importance of the possible causes. This is especially relevant in the case of the role of wildlife reservoirs
Guta S., Casal J., Napp S., Saez-Llorente JL., Garcia-Saenz A., Perez de Val B., Romero B., Alvarez J. y Allepuz A.
| National Animal Health Diagnostic and Investigation Center (NAHDIC). | |
 | Centre de Recerca en Sanitat Animal (CReSA). Universitat Autònoma de Barcelona (UAB). |
| Departamento de Sanidad y de Anatomía Animal. Facultad de Veterinaria. Universitat Autònoma de Barcelona (UAB). |
 | Servicio de Micobacterias (MYC). Centro de Vigilancia Sanitaria Veterinaria (VISAVET). Universidad Complutense (UCM). |
 | Department of Veterinary Population Medicine. College of Veterinary Medicine. University of Minnesota (UMM). |
