Investigación publicada en Veterinary Microbiology

24 de febrero de 2012

Test-and-slaughter strategies have been the basis of bovine tuberculosis (BT) eradication programs worldwide; however, eradication efforts have not succeeded in certain regions, and imperfect sensitivity and specificity of applied diagnostic techniques have been deemed as one of the possible causes for such failure. Evaluation of tuberculosis diagnostic tools has been impaired by the lack of an adequate gold standard to define positive and negative individuals. Here, a Bayesian approach was formulated to estimate for the first time sensitivity (Se) and specificity (Sp) of the tests [single intradermal tuberculin (SIT) test, and interferon-gamma (IFN-γ) assay] currently used in Spain. Field data from the first implementation of IFN-γ assay (used in parallel with SIT test 2-6months after a first disclosure SIT test) in infected beef, dairy and bullfighting cattle herds from the region of Castilla and Leon were used for the analysis. Model results suggested that in the described situation: (i) Se of SIT test was highly variable (40.1-92.2% for severe interpretation, median=66-69%), and its Sp was high (>99%) regardless interpretation criteria; (ii) IFN-γ assay showed a high Se (median=89-90% and 83.5% for 0.05 and 0.1 cut-off points respectively) and an acceptable Sp (85.7% and 90.3% for 0.05 and 0.1 thresholds) and (iii) parallel application of both tests maximized the combined Se (95.6% using severe SIT and 0.05 cut-off point in the IFN-γ assay). These results support the potential use of the IFN-γ assay as an ancillary technique for routine BT diagnosis

Alvarez J., Perez AM., Bezos J., Marques S., Grau A., Saez-Llorente JL., Minguez O., de Juan L. y Dominguez L..

Evaluation of the sensitivity and specificity of bovine tuberculosis diagnostic tests in naturally infected cattle herds using a Bayesian approach

Evaluation of the sensitivity and specificity of bovine tuberculosis diagnostic tests in naturally infected cattle herds using a Bayesian approach

	Servicio de Micobacterias (MYC). Centro de Vigilancia Sanitaria Veterinaria (VISAVET). Universidad Complutense (UCM).
	Departamento de Sanidad Animal. Facultad de Veterinaria. Universidad Complutense (UCM).
	University of California-Davis (UCDAVIS).
	Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET).
	Subdirección General de Sanidad de la Producción Primaria. Dirección General de Recursos Agrícolas y Ganaderos.
	Ministerio de Medio Ambiente y Medio Rural y Marino (MARM).
	Instituto de Investigación en Recursos Cinegéticos (IREC). Consejo Superior de Investigaciones Científicas (CSIC). Universidad de Castilla La Mancha (UCLM). Gobierno de Castilla-La Mancha (JCCM).
	Servicio de Sanidad Animal. Junta de Castilla y León.