Impact of hemorrhagic fever with renal syndrome control policies in Hebei Province: an interrupted time series analysis

Hebei Province is one of China’s high-incidence regions for hemorrhagic fever with renal syndrome (HFRS), posing significant public health challenges. This study aims to evaluate the efficacy of key Hemorrhagic Fever with Renal Syndrome (HFRS) control measures. This study analyzed annual incidence data (1981–2024) and monthly data (2004–2024) using interrupted time series (ITS) analysis and the X-12 seasonal adjustment method. The X-12 procedure decomposes the series into trend, seasonal, and irregular components and removes seasonal variation to produce seasonally adjusted data. Specifically, we assessed the impact of two interventions: the 2002 Hebei Epidemic Hemorrhagic Fever Prevention and Control Plan and the 2008 Vaccination Work Plan for Key HFRS-endemic Counties in Hebei Province. The results demonstrated that before 2002, the HFRS incidence rate increased significantly at 28.8% annually ( β₁ = 0.25, p < 0.01). After policy implementation, the trend reversed, with an annual decline of 32.0% ( β₁ + β₃ = −0.117, p < 0.05), indicating effective control. Notably, epidemic peaks temporarily elevated incidence levels ( β₄ = 0.83, p < 0.01). Following the 2008 vaccination program, short-term incidence rate reductions of 1.229 cases per 100,000 ( β₂ = -1.229, p = 0.044) and 0.351 cases per 100,000 ( β₂ = -0.351, p = 0.10) were observed in Qinhuangdao and Tangshan, respectively, though the latter was not statistically significant. Long-term trends revealed slower monthly declines of 0.003 cases per 100,000 in Qinhuangdao ( β₁ + β₃ = −0.003, p = 0.049) and 0.002 cases per 100,000 in Tangshan ( β₁ + β₃ = −0.002, p = 0.019). These findings highlight the differential effects of policy interventions on HFRS incidence, with the 2002 plan achieving sustained reduction, while the 2008 vaccination program showed limited long-term impact. Not applicable.