Elisa And Mat Tests For Leptospira Interogans Detection From Cattle In Eastern Algeria

Abstract

Leptospira interrogans is one of the most common infectious organisms worldwide that causes severallosses in cattle. As far as we know, few previous studies have focused on Leptospira interrogans infection in cattlefrom Algeria. This study aimed to assess the prevalence of bovine leptospirosis, identify selected risk factors, andcompare two different detection tests. 611 blood samples from 67 cattle farms were collected in six Algerian provinces;Algiers, Boumerdès, Bordj Bou Arreridj, Sétif, Batna, and Souk Ahres. Sera samples were analyzed for the presence ofantibodies against five serovars of Leptospira interrogans using a microscopic agglutination test (MAT), using 50% agglutination,at a dilution ≥1: 100 as a cut-off point. A commercial indirect enzyme-linked immunosorbent assay (ELISA)test was used to determine the seroprevalence against L. interrogans serovar Hardjo. Moreover, a survey throughbreeders’ questionnaires was conducted to identify the potential risk factors of Leptospira interrogans infection. Theseroprevalence of L. interrogans infection using MAT in the cows was 17.02% (95% confidence interval [CI]: 14.12-20.24) and in the farms was 83.58% (95% CI: 59.31-81.99). The most commonly detected serovar was Hardjo 6.71%(95% CI: 4.86-8.99) followed by Icterohaemorrhagiae 5.07% (95% CI: 3.47-7.12). Finally, the last serovar present wasthe Grippotyphosa 2.78 (95% CI: 1.63-4.42). The comparison between the two serological methods, considering theMAT as the reference test, shows that the PrioCHeck ELISA kit had a sensitivity of 63.4% (95% CI: 48.7-78.2), a specificityof 98.9% (95% CI: 98.1-99.8), and a reliability of 96.6% (95% CI: 95.1-98.0). The kappa coefficient was 0.62,and the McNemar test showed a P = 0.23. Multivariable logistic regression analysis showed that the semi-intensivesystem was a protective factor against leptospirosis, with an odds ratio of 0.35 (95% CI: 0.16-0.78). The study findingsindicate that leptospirosis is a serious issue in farms located in selected provinces in Algeria, with a high incidence ratenoted there. The semi-intensive system’s significance as a leptospirosis protective factor is to create control strategiesthat decrease the probability of infection in both humans and cattle.