Canine leptospirosis, United States, 2002-2004

Area of Science:

• Veterinary Medicine
• Infectious Diseases
• Bacteriology

Background:

• Leptospirosis is a significant zoonotic disease affecting dogs worldwide.
• Microscopic agglutination tests (MAT) are standard for diagnosing leptospirosis.
• Understanding serovar prevalence and trends is crucial for public health and canine care.

Purpose of the Study:

• To analyze trends in canine leptospirosis seropositivity from 2002 to 2004.
• To identify the most prevalent Leptospira serovars in the studied canine population.
• To investigate serologic correlations between different serovars.

Main Methods:

• Retrospective analysis of 23,005 canine serum samples tested via MAT.
• Statistical analysis to determine significant increases in positive test proportions.
• Evaluation of serovar prevalence and correlation coefficients.

Main Results:

• A significant increase in positive Leptospira MAT results was observed from 2002 to 2004 (p < 0.002).
• Serovars Autumnalis and Grippotyphosa showed the highest prevalence (p < 0.05).
• A strong positive serologic correlation (r = 0.72) was found between Autumnalis and Pomona.

Conclusions:

• Canine leptospirosis showed an increasing serologic trend during the study period.
• Autumnalis and Grippotyphosa serovars were dominant, indicating potential geographic or environmental factors.
• The strong correlation between Autumnalis and Pomona suggests shared antigenic properties or co-infection patterns.