Relationship between geographic characteristics and prevalence of tsutsugamushi disease in southeastern costal areas of China

ObjectiveTo identify the epidemio logical features of tsutsugamushi disease in south eastern costal areas of China to provide basis for the prevention of the disease.MethodsRepresentative sites for the investgation in Fujian,Zhejiang and Jiang suprovinces were selected.Data on geographical landscape and the epidemic of the disease were collected.Field survey and experimental studies on rats and chiggermites inrelation to tsutsugamushi disease were carried out.ResultsThe seasonal distribution of tsutsugamushi disease in southeastern costal areas of China could be divided mainly into two types.The summer type was prevalent from May to October in Fujian and Zhejiang provinces.Main animal hosts were Rattus losea,R.flavipectus;main vectormite was Leptotrom bidium deliense.The type of Orientia tsutsuga mushi(Ot)was Gilliam.The autumn-winter type was prevalent from October to Decem ber in Jiangsu province and the main animal hosts were Apodemus agrarius,R.norregicus;main vector mite was L.scutellare.The type of Ot was Kawasaki.ConclusionThe types of Ot, animal host, vector chigger mites and epidemio logical features of tsutsugamushi disease are different in Fujian,Zhejiang and Jiangsu provinces.Thus,the preventive measures should be different.