[Geographical divisions of rat transmissible diseases].

In order to prevent rat transmissible diseases, it is necessary to know the geographical distribution of rats, their external parasitic arthropod and rat-borne disease in human, and to make a graph of geographical division. Stratified sampling was conducted by county to capture rats, and to sort out flea for identification of their genus and species. A total of 55,064 rats sorting as 6 families, 17 genera and 21 species were captured, and a total of 34,733 flea sorting as 4 families, 25 genera and 53 species were picked. Three kinds of rat-borne diseases, namely plague, leptospirosis and epidemic hemorrhagic fever have been occurred and epidemic in Shanxi Province. Following the general principles for geographical division, Shanxi Province was divided into 4 sub-regions: (1) basin among mountains and prairie in Yanbei; (2) loess plateau, hill and prairie with shrub in the west; (3) hill, shrub and basin, prairie with forest in the middle part; (4) hill, basin with forest and prairie in the southeast. When bubonic plague was epidemic, its transmissible mode was probably Meriones meridianus--Xenopsylla conformis--Mus musculus, Rattus norvegicus--Xenopsylla cheoopis--human. Bubonic plague has been occurred within Xingxian and Linxian conxian counties of the second sub-region. Leptospirosis has been occurred in Xiangfen county of the third sub-region, the source of infection was from pigs instead of rats. Epidemic hemorrhagic fever has been occurred in the third and fourth sub-regions, the source of infection was mainly from Ruttus norvegicus.