Epidemic strength and curve fitting models for hemorrhagic fever with renal syndrome

  Objective   To predict the epidemic strength and tendency for hemorrhagic fever with renal syndrome (HFRS).

  Methods   Data on HFRS incidences of 31 national surveillance spots from 1982 to 1999 were analyzed by epidemic strength classification and polynomial fitting.

  Results   Five high-rate areas, 9 medium-rate areas, and 17 low-rate areas were identified.Data on incidences of 24 surveillance spots for 18 years, and incidences of 5 surveillance spots for 9 years were used to fit polynomial models.Model tests of 26 surveillance spots were obtained with P < 0.05.

  Conclusion   In 1990's, the highest rates wre found in 1994 and 1995, and the incidence rates showed an increase around 2000 in most areas.Polynomial fitting was a good method for HFRS incidences.