安徽省沿江沿淮地区洪涝灾害前后钩端螺旋体病监测

目的分析洪涝灾害对钩端螺旋体（钩体）病爆发性流行因素所产生的影响及规律。方法在安徽省沿江、沿淮易发生洪涝灾害地区设立监测点，通过不同时期对自然人群和宿主动物感染钩体情况的调查，在汛期前、洪涝灾害期间、灾后，对自然人群、宿主动物开展血清流行病学调查，采集主要宿主动物标本进行病原分离。结果沿江地区1998年洪涝灾害期间自然人群钩体感染率为13．49％，高于灾后的2．墙％，差异有统计学意义（X^2=22．78，P〈0．01）。沿淮地区2003年洪涝灾区与非灾区自然人群钩体平均感染率分别为248％和5．35％。结论洪涝灾害能够对灾区钩体病的发生产生影响，是否会导致该病流行，主要取决于传染源带菌率高低、洪涝灾害的规模、洪水持续时间、洪涝灾害发生时间与钩体病流行季节是否一致、易感人群免疫水平等因素。但传染源带菌率的高低是确定钩体病流行或大流行的关键因素。

Study on a monitoring program regarding leptospirosis in some fore-and-after flood-affected areas along large rivers in Anhui province

Objective The study was designed to find out the epidemic characteristics of leptospriosis and to develop effective intervention measures. The effects of floods on leptospriosis in some areas along Yangzi river and Huai river in Anhui province was also analysed. Methods Study on serum epidemiology of leptospriosis was carried out from serous samples collected from native residents and animal hosts including isolation of pathogens at different phases (before, middle and after) and different monitoring spots,during the floods. Results Infection rate with leptospriosis pathogen among native residents was 13.49% during the flood-period,much higher than 2.18% at post-flood(x2 = 22.78,P<0.01) stage,in the flood-affected areas along Yangzi river in 1998. The average rates of infection were 2.48% and 5.35% in affected and unaffected areas along Huai river respectively, in 2003. Conclusions There was full evidence that floods causing the epidemics of leptospriosis. However, the transmission of leptospriosis among people would depend on affecting factors as scales of floods, lasting time, coincidence between flood happening and epidemic season, immuno-protection level against leptospriosis among people and so on to a great extent. Factors as the magnitude of pathogens carried by various kinds of infectious sources were also important determinants affecting the nature, being epidemic or pandemic of leptospriosis. It was suggested that active surveillance network on the sources of infection and risk factors of leptospriosis should be developed for the control and prevention of the disease,in the flood-hit areas.