Seroprevalence and risk factors of Leptospira serovar Pomona and Leptospira serovar Hardjo infection in dairy cows in Jordan.

Introduction: This study was carried out to determine the seroprevalence and risk factors associated with Leptospira serovars Pomona and Hardjo infection in dairy cows.

Methodology: Seroprevalence was determined using ELISA using 160 healthy and 80 recently aborted cows. Risk factor assessment was carried out using a pre-validated questionnaire.

Results: The true farm seroprevalence of Leptospira serovars Pomona and Hardjo was 92.3% (95% CI: 66%-98%). In healthy cows, the true and apparent cow seroprevalence of Leptospira serovars Pomona and Hardjo were 26.9 (95% CI: 20-34%), 26.25% (95% CI: 20-33%) and 28.75% (95% CI: 22-36%) and 27.5% (95% CI: 21-35%), respectively. Semi-intensive management system (OR = 11.43; P < 0.01), surface water as a source of drinking water (OR = 1.21; P < 0.03), lack of special wear for visitors (OR = 1.39; P < 0.05), and previous history of abortion (OR = 1.02; P < 0.05) were associated with high rate of seropositivity against Leptospira serovars Pomona and Hardjo. In recently aborted cows, the true and apparent seroprevalence rates of Leptospira serovars Pomona and Hardjo were 53.25% (95% CI: 47.5-62%), 53.75% (95% CI: 48.5-63.2%) and 56% (95% CI: 49-61%), 56.25% (95% CI: 49.8-61.2%), respectively.

Conclusions: Leptospirosis is an endemic disease in Jordan and further studies are required to effectively control the disease in dairy cows.