Serologically Confirmed Human Leptospirosis in Colombia, 2015-2020

Area of Science:

• Infectious Diseases
• Epidemiology
• Public Health Microbiology

Background:

• Leptospirosis is a significant bacterial zoonotic disease with a global health impact, transmitted via infected animals or contaminated environments.
• Colombia has a mandatory reporting system for leptospirosis since 2007, utilizing the microscopic agglutination test (MAT) for case confirmation.
• Existing surveillance limitations obscure a full understanding of leptospirosis's epidemiology, including geographical spread, causative agents, and severe disease burden.

Purpose of the Study:

• To provide a comprehensive epidemiological overview of confirmed human leptospirosis cases in Colombia from 2015 to 2020.
• To analyze risk factors, incidence, mortality, and geographical distribution of leptospirosis in the country.
• To offer insights into the current status of leptospirosis and propose improvements for diagnosis and disease management.

Main Methods:

• Retrospective analysis of 3,535 serum samples submitted to the National Institute of Health (INS) laboratory for suspected leptospirosis.
• Confirmation of cases using the microscopic agglutination test (MAT).
• Calculation of incidence rates and analysis of demographic data, mortality, and geographical distribution.

Main Results:

• A total of 880 out of 3,535 suspected cases (25%) were confirmed as leptospirosis.
• The overall incidence was 1.9 cases per 100,000 population, with a marked male predominance (82.1%).
• Leptospirosis contributed to 54 (6.1%) deaths, with cases reported across most Colombian regions.

Conclusions:

• The study highlights the persistent public health burden of leptospirosis in Colombia.
• Strengthening laboratory surveillance, implementing targeted prevention strategies, and improving diagnostic capacities are urgently needed.
• This epidemiological data is foundational for estimating the true impact of leptospirosis and informing public health interventions.