OBJECTIVETo study the incidence and spatiotemporal dynamic variation of hemorrhagic fever with renal syndrome (HFRS) in Shandong province.

METHODSAccording to surveillance data on HFRS epidemics and host animals, a 'contour area multifractal model' was estimated on the HFRS' incidence and multi-analysis model was applied to study spatiotemporal dynamic variation.

RESULTSThe process could be classified into 5 periods: 1st period (1974-1981) when HFRS was in completely natural focal state in Shandong, and the nature of focus was typical Apodemus type. 2nd period (1982-1986) indicated the process of expanding and merging of the Apodemus type focus in the southeastern part of Linyi district and the Rattus type focus was in the southern part of Jining city. 3rd period (1987-1990) indicated that through the expanding and merging of the two epidemic focuses,one mixed focus dominated by the Apodemus type had been formed in the hilly area of the southern and middle part of Shandong while another one dominated by the Rattus type in the Yellow River valley of the northwestern part of Shandong. 4th period (1991-1993) showed that the process of the spatial pattern of the mixed focus dominated by the Rattus type in Shandong. 5th period (1994-2004) referred to the spatial pattern of the mixed focus dominated by the Rattus became stabilized.

CONCLUSIONEvolution of the characteristics of HFRS focus in Shandong province experienced the following three processes: the simple Apodemus type and the simple Rattus type were seen separately to the mixed foci with the Apodemus type dominant and the Rattus dominant type coexisted and merged to the stable state of the mixed focus with Rattus as the dominant one.