Human leptospirosis in an area of central Italy: results from a serological survey.

The results of a serosurvey for leptospiral antibodies in a random sample of healthy subjects are reported. The study was carried out in an area where a waterborne outbreak of leptospirosis, due to leptospires of serogroup Australis, had occurred a month before. Sera were tested with the microagglutination technique. Leptospiral agglutinins were found in 13.8% of tested subjects, mostly in adult females. The highest prevalence rate was observed for serovar lora belonging to serogroup Australis. The leptospires of this group have a relevant spread in the study area in keeping with other surveys carried out in Italy.