Enhanced detection of Leptospira in cattle: Comparative performance of loop-mediated isothermal amplification, polymerase chain reaction and serological methods.

Leptospirosis is a globally distributed zoonotic disease. This study aimed to evaluate the performance of loop-mediated isothermal amplification (LAMP) in detecting Leptospira DNA in bovine samples compared to conventional lipL32 PCR and serological methods. A total of 464 serum, 96 urine, and 31 organ samples were analyzed using LAMP, lipL32 PCR, and the microscopic agglutination test (MAT). The results showed that 52.8 % of sera tested positive exclusively by MAT, indicating past exposure, while 1.2 % tested positive by molecular techniques, suggesting early infection. In urine samples, LAMP detected leptospiral DNA in 62.5 % of cases, highlighting its potential for identifying asymptomatic carriers. Among organ samples from aborted fetuses, 22.6 % were positive by both molecular techniques, supporting Leptospira as a potential cause of fetal loss. Notably, LAMP exhibited a high diagnostic sensitivity (100 %, 95 % CI: 93.5-100 %) and specificity (95.4 %, 95 % CI: 93.2-97.0 %), outperforming lipL32 PCR in DNA detection. Additionally, Cohen's Kappa index (0.792) indicated substantial agreement between LAMP and lipL32 PCR. Given its higher sensitivity, rapid turnaround, and affordability, LAMP represents a valuable tool for improving leptospirosis diagnosis, particularly in resource-limited settings. These findings underscore the importance of integrating molecular and serological techniques for a more accurate detection of Leptospira infection in cattle.