[An investigation on the distribution of leptospirae interrogans in water and soil in southwest of Yunnan Province].

The conservation of pathogenic leptospirae in water and soil is one of the important problems of geography-epidemiological survey of leptospirosis. We have conducted this investigation by using of filtration-culture isolation method in five counties in the west and southwest of Yunnan during 1988-1992. The results showed that the isolates from samples of water and soil collected between July and September in Menglian and Huaping county were leptospirae biflexa while in the samples of water and soil collected between November and December in three counties, 8 strains of L. interrogans were isolated from the samples of Gengma and Baoshan county. The total positive rate was 3.31% (8/242). The positive rate of water and soil was 2.14% (3/140) and 4.9% (5/102) respectively. Strains obtained in this investigation belong to six serogroups: Icterohaemorrhagiae and Pyrogenes in 2 respectively. Canicola, Grippotyphosa, Sejroe and Australis in 1 respectively. These serogroups of leptospirae obtained from water and soil were corresponded with the serogroups obtained from the patients and animals with leptospirosis in local area. This survey provided new data for expounding the structure of the focus of leptospirosis.