Veterinary Microbiology publish this investigation article

March 30^th, 2009

Interferon-gamma (IFN-gamma) detection assay is being applied as an ancillary test to tuberculin tests in the diagnosis of bovine tuberculosis to detect the maximum number of infected animals. Among possible factors influencing the performance of tuberculosis-diagnostic tests, paratuberculosis, a widespread disease in Spain and other European countries, has been pointed out as a cause of false positive reactions. Still, its effect on the sensitivity of these tests in cattle has yet to be fully characterized. The impact of paratuberculosis in the apparent sensitivity of IFN-gamma assay was studied in a bullfighting cattle herd with a mixed tuberculosis-paratuberculosis infection, using culture of Mycobacterium bovis and Mycobacterium avium paratuberculosis as the gold standard to determine the infection status of every animal. A total of 218 animals were slaughtered and sampled for bacteriology after blood sampling. IFN-gamma assay showed a lower apparent sensitivity in animals with a mixed infection (50%) compared to all animals suffering tuberculosis (78.3%). This finding indicates that the presence of paratuberculosis in tuberculosis-infected herds could imply a serious impairment in the sensitivity of IFN-gamma detection test

Alvarez J., de Juan L., Bezos J., Romero B., Saez-Llorente JL., Marques S., Dominguez C., Minguez O., Fernandez-Mardomingo B., Mateos A., Dominguez L. and Aranaz A.

Effect of paratuberculosis on the diagnosis of bovine tuberculosis in a cattle herd with a mixed infection using interferon-gamma detection assay

Effect of paratuberculosis on the diagnosis of bovine tuberculosis in a cattle herd with a mixed infection using interferon-gamma detection assay

	Departamento de Sanidad Animal. Facultad de Veterinaria. Universidad Complutense (UCM).
	Dirección General de Ganaderia. Ministerio de Agricultura, Pesca y Alimentación (MAPA).
	Servicio de Micobacterias (MYC). Centro de Vigilancia Sanitaria Veterinaria (VISAVET). Universidad Complutense (UCM).
	Servicio de Sanidad Animal. Junta de Castilla y León.
	Laboratorio Regional de Sanidad Animal. Junta de Castilla y León.