湖南省洪涝灾害高发地区钩端螺旋体病流行因素的研究

Study on the factors leading to the prevalence of leptospirolsis in flood-hit areas in Hunan Province.

目的 研究湖南省洪涝灾害高发地区钩端螺旋体病的流行因素。 方法 选择洞庭湖区 6个县研究传染源密度、带菌情况和自然人群、病人与动物抗体水平 ,按国家有关标准进行实验室和现场工作。 结果 ( 1)传染源 :灭鼠前、后和钩体病流行后期鼠密度分别为 7 0 2 %、2 3 1%和 4 64 % ,优势鼠种为黑线姬鼠 ,灭鼠后鼠密度下降了67 0 9% ;村民家庭家畜饲养以圈养形式占 99 15 % ,喂商品混合饲料的占 72 3 3 %。 ( 2 )病原学 :对鼠、猪、犬和病人的标本进行钩体培养 ,分离出 82株钩体 ,黄疸出血群占 70 73 % ,1株国内新型菌 ,黑线姬鼠分离率高达 11 0 3 %。 ( 3 )血清学 :检测 12 63名自然人 15个群钩体抗体 ,一群以上抗体阳性率未接种钩体苗者为 5 0 88% ,接种一针四价钩体者为72 5 5 % ,人群抗体有 14群之多 ;检测 85例病人双份血清抗体 ,确诊 63例 ,符合率 74 11% ,黄疸出血群感染比例最高 ;流行季节牛、犬和出栏猪抗体分别有 14、8和 7个群 ,牛阳性率最高。 结论 流行前灭鼠效果好 ,不仅降低了鼠密度 ,还降低了带菌率 ;主要传染源是鼠和牛 ,牛作为传染源的意义大于猪和犬 ;人群接种一针四价钩体菌苗亦有效 ;病人感染黄疸出血。

Objective To study the prevalence factors for leptospirosis in flood-hit areas in Hunan Province. Methods Six counties in Dongting Lake area were selected to study the density of infection source,bacteria-bearing condition and antibody level in natural population,patients and animals.Laboratory and field work were carried out according to related national standards. Results (1)Source of infection:The rat dentisyry before,after deratization and during the late stage of leptospirosis prevalence was 7.02%,2.31% and 4.64% respectively.The dominant rat was Apodemus agrarius and its density decreased by 67.09% after deratization.The investigation on domestic animal raising pateerns revealed that raising in pens accounted for 99.15%,and 70.73% of the animals were feed on markedly mixed food.(2)Etiology:82 strains of leptospirosis were separated from samples from rate,pige and patients by leptospirosis cultivation.Among them,70.73% is icterohemorrhagic form,one strain is a new type in China.The separation rate in Apodemus agrarius was up to 11.03%.(3)Serology:15 types of antibody in 1 263 natural population were detected.It was found out that antibody positive rate for more than one type among people who had not received leptospirosis vaccine was 50.88%,and the rate among people who received one 4-valence leptospirosis vaccine was 72.55%.The types of antibodies in people were more than 14.Antibodies in double sera from 85 patients were detected and 63 were confirmed.The coincidence rate was 74.11%.The infection rate of icterohemorrhagic form was the highest.During prevalence season,the types of antibodies presented in cows,dogs and out-of-pen pigs were 14?8 and 7 respectively and the positive rate in cows was the highest. Conclusion Deratization before prevalence was an effective way.It decreased not only rat dentistry,but also bacteria-bearing rate.The main sources of infection for leptospirosis were rate and cows.The significance of cows as source of infection was greater than pigs and dogs.Vaccination of one four-valence leptospirosis vaccine was also effective.lcterohemorrhagic form,Australian form and Autumn form were the main types of infection for people.