To investigate the influence of the variations of an epidemic focus on hemorrhagic fever with renal syndrome (HFRS) so as to provide a basis for effective control of HFRS.

HFRS epidemic data from the rapid development of urbanization of Huangdao District and the general development of Jiaonan City were collected and analyzed retrospectively from 1979 to 2014. And the HFRS cases, incidences, host animals and Hantavirus surveillances were compared.

The three epidemic peaks occurred from 1979 to 2014 in Huangdao District and Jiaonan City, they were in the mid-1980s (1983-1987), the late 1990s (1995-1999) and around 2012 (2010-2014), and 954, 80, 37 and 2 506, 614, 432 cases were reported, respectively, in Huangdao District and Jiaonan City. The three peak years were 1986, 1999 and 2012. And the annual incidences of Huangdao District were 385.73/100 000, 15.64/100 000 and 2.51/100 000, respectively. The annual incidences of Jiaonan City were 67.07/100 000, 28.68/100 000 and 14.68/100 000, respectively. The three peaks obviously appeared double peaks [the autumn and winter (from Oct. to Dec.) and the spring (from Jan. to Feb.)] in Jiaonan City. And the first peaks in Huangdao District was in the autumn and winter (from Oct. to Dec.) and the spring (from Jan. to Feb.), the second and the third were only in the autumn and winter (from Oct. to Dec.). Eight kinds of host animals were detected in Jiaonan City from 2005 to 2014. They were house mouse [27.53% (1 108/4 024)], brown rat [25.50% (1 026/4 024)], striped field mouse [14.84% (597/4 024)], black rat [10.74% (432/4 024)], hamsters [11.01% (443/4 024)], shrew [8.72% (351/4 024)], back grain hamster [1.02% (41/4 024)] and club rat [0.65% (26/4 024)]. Two kinds of host animals were detected in Huangdao District. They were house mouse [57.14% (16/28)] and brown rat [42.86% (12/28)]. The capture rates in Jiaonan City were higher than those of Huangdao District. The capture rate in 2012 was 8.04% (855/10 638) and the capture rates in Huangdao District were all lower than 0.84%. The total detection rate in Jiaonan City was 2.81% (113/4 024). And there was no positive detection for ten years in Huangdao District.

HFRS epidemic intensities have receded gradually in Huangdao District and Jiaonan City. The epidemic in Huangdao District obviously presents a low epidemic condition after the first peak. The few kinds and low densities of host animals are resulting in the sustainable condition. The evolution of epidemic patterns of HFRS is related to the change of epidemic sources by the differences in urbanization between the two places.

Hemorrhagic fever with renal syndrome; Urbanization; Eepidemic foci; Host animals; Epidemic characteristics; Ecological characteristic