Analysis on epidemic characteristics of leptospirosis in Changshan County of Zhejiang Province from 1991 to 2004

Objective The study was performed to understand the epidemic characteristic of lep-tospirosis in Changshan County，and SO provide scientific evidence for formulation of relevant preven- tion and control measures．Methods A descriptive epidemiological method was applied to analysis on the epidemic characteristic of leptospirosis in Changshan County of Zhejiang Province from 1991 to 2004，and the main epidemic bacterial colonies were explored through aetiological and serological monitoring for patients and host animals．Results The average incidence rate of leptospirosis in Changshan County from 1991 to 2004 was 19,29/lakh，and the patients were mainly young and mid-dle-aged farmers，with the male more than the female．The peak period of incidence was from July tO September,and the epidemic stype was of field．The aetilogical monitoring detected 32 strains of lep-tospira，mainly L．Icterohemorrhagic，which occupied 59.38％(19/32)．The positive rate of serological monitoring was 50.74％(171/337)，mainly L．Icterohemorrhagic and L．Hebdomadis，50.29％and 30.41％ repccfively．Apodemus agrarius was the predominant rat for this，with a carrier rate of 4.32％， while for frog，pig and cattle，no carrier was found．Conclusion L．Icterohemorrhagic and L．Hebdo-madis were the main epidemic bacterial colonies of leptospira in Changshan County，and the main host animal was apodemus agrarius．The prevalence of this disease may be effectively controlled by adopt-ing corresponding vaccine inoculation as a primary measure．