Large-scale evaluation of bacteriological-based method and qPCR performance for Brucellosis diagnosis in livestock using Bayesian latent class analysis

The performance of direct tests, such as bacteriological culture and qPCR, for the diagnosis of brucellosis has been evaluated in a limited number of studies, often based on small sample sizes. Moreover, the absence of a gold standard makes this assessment even more challenging. A potential alternat...

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Bibliographic Details
Published in:Veterinary Quarterly
Main Authors: Giovanna Fusco, Alessandro Bellato, Lorena Cardillo, Agata Campione, Michela Di Roberto, Anna Cerrone, Francesca Bove, Roberta Pellicanò, Maria Ottaiano, Marco Esposito, Antonio Limone, Anna Rita Attili, Esterina De Carlo
Format: Article
Language:English
Published: Taylor & Francis Group 2025-12-01
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Online Access:https://www.tandfonline.com/doi/10.1080/01652176.2025.2514753
Description
Summary:The performance of direct tests, such as bacteriological culture and qPCR, for the diagnosis of brucellosis has been evaluated in a limited number of studies, often based on small sample sizes. Moreover, the absence of a gold standard makes this assessment even more challenging. A potential alternative for evaluating the performance of direct tests is Bayesian latent class analysis (BLCA), which does not require prior knowledge of disease status or a gold standard. This study aimed to estimate the sensitivity (Se) and specificity (Sp) of bacteriological culture for brucellosis diagnosis. In a brucellosis-endemic area, a large number of seronegative and seropositive buffaloes and cattle were tested using bacteriological culture and qPCR. BLCA was applied to estimate the performance of both tests. The median Se of bacteriological culture was estimated at 61.3%, compared to 70.9% of qPCR. The median Sp was 99.6% for bacteriological culture and 89.3% for qPCR. Bacteriological culture demonstrated a higher Positive Predictive Value (PPV) than qPCR in both buffaloes and cattle, whereas the Negative Predictive Value (NPV) of the two methods did not differ significantly. These results suggest that, in settings of low brucellosis prevalence, a positive bacteriological culture has a greater predictive value than qPCR .
ISSN:0165-2176
1875-5941