Studies on three types of natural foci of tsutsugamushi disease in eastern part of China

WU Guang-hua; GUO Heng-bin; YU Ming-ming

Abstract：Objective In order to identify the types of natural foci of tsutsugamushi disease to provide basis for prevention,a series of studies were carried out in Fujian,Zhejiang and Jiangsu Provinces. Methods ①Selecting representative points for investigation in three Provinces.②Collecting data on geographical landscape and epidemiology.③Field survey and experimental studies on rats and chigger mites in relation to the disease. Results Three representative types of natural foci of tsutsugamushi disease were demonstrated.They were ①Coastal island type,mainly in Fujian with major reservoir host as Rattus losea and major vector mite as L.deliense;prevalent season:sum0mer; type of Ot( Orientia tsutsugamushi) Gilliam.②Inland mountain- forest type in Zhejiang with major reservoir host as Niviventer confucianus and major vector mite as L.gaohuense; prevalent season:summer; type of Ot:Gilliam.③Inland plain-hills type in Jiangsu with major reservoir hosts:Apodemus agrarius,N.confucianus,R.norvegicus and Crocidura lasiura;major vector mite:L.scutellare;prevalent seasons:autumn and winter; type of Ot:Kawasaki. Conclusion The types of Ot,reservoir hosts,vector chigger mites and epidemiological features of tsutsugamushi disease in Fujian,Zhejiang and Jiangsu Province were found different.Thus,the preventive measures should also be distinct from one another.