Investigation published in Frontiers in veterinary science

February 8^th, 2024

Caprine tuberculosis (TB) is a zoonotic disease caused by members of the Mycobacterium tuberculosis complex. TB eradication programs in goats are based on the single and comparative intradermal tuberculin tests (SITT and CITT, respectively). Antibody-based diagnostic techniques have emerged as potential diagnostic tools for TB. P22 ELISA has been previously evaluated using samples collected after the intradermal tuberculin tests to maximize the sensitivity, a phenomenon known as booster effect. However, there is no information available on whether the use of this diagnostic strategy could lead to a decrease of its specificity (Sp). The aim of the present study was to elucidate the interference effect of a recent CITT on the Sp of the P22 ELISA in serum and milk samples collected at different times after the CITT from a TB-free herd (n = 113). The number of reactors to P22 ELISA was significantly higher (p < 0.01) on serum samples collected 15 days post-CITT compared to day 0, showing a decrease in Sp from 99.1% (95% CI; 95.2–99.8%) to 88.5% (95% CI; 81.3–93.2%). The number of reactors and the quantitative values of P22 ELISA were significantly higher (p < 0.01) in serum samples compared to milk. No significant (p > 0.05) changes in the Sp of the P22 ELISA were observed throughout the different time samplings using milk No significant (p > 0.05) changes were observed on days 30 and 60 post-CITT. In conclusion, the booster effect strategy may significantly decrease the Sp of P22 ELISA in TB-free herds when serum samples are used but not when milk is tested

Velasco-Reinaldos C., Ortega J., Rincón-Fernández de la Puente J., Romero B., de Juan L., Dominguez L., Dominguez M., Moreno I., Alvarez J. and Bezos J..

Effect of a recent intradermal test on the specificity of P22 ELISA for the diagnosis of caprine tuberculosis

Effect of a recent intradermal test on the specificity of P22 ELISA for the diagnosis of caprine tuberculosis

	Servicio de Micobacterias (MYC). Centro de Vigilancia Sanitaria Veterinaria (VISAVET). Universidad Complutense (UCM).
	Departamento de Sanidad Animal. Facultad de Veterinaria. Universidad Complutense (UCM).
	Servicio de Inmunología. Centro Nacional de Microbiología (CNM). Instituto de Salud Carlos III (ISCIII).
	Servicio de Ensayos Clínicos (SEC). Centro de Vigilancia Sanitaria Veterinaria (VISAVET). Universidad Complutense (UCM).