[Evolution of leptospirosis according to the National Epidemiological Surveillance System, Chile 2003-2009]

Since 2002, leptospirosis is a disease, which requires universal and immediate notification in Chile. Furthermore, it is an agent of laboratory surveillance.

To describe leptospirosis in Chile and its evolution from the beginning of the obligatory notification and surveillance to the last year of available information.

A descriptive analysis of the data registered from 2003 to 2009 was conducted using different databases of cases reported to the Ministry of Health (registry of notified cases, hospital discharges, laboratory registry, and deaths). As a zoonosis, animal cases registered by the Servicio Agrícola y Ganadero were also included, in order to establish an association in terms of space and temporary distribution. In accordance with the International Classification of Diseases, 10th revision, the codes A270 (icterohaemorragic leptospirosis), A278 (other forms), and A279 (leptospirosis, not specified) were distinguished.

Crossing of information from the different sources revealed an underreporting of the disease, making it impossible to determine the incidence rate and defining it only as a reporting rate.

According to these data, the disease tends to decrease. There was a correlation between the regions with highest human and animal cases, corresponding to the regions of Bio Bio and Maule; comparing the years of notification, there was no temporal correlation. Our study suggests that the surveillance of this disease should be further evaluated for its consistency, comparability, validity, sensitivity, and integrity.