Abstract: Objective To analyze the long-term epidemic trends of hand-foot-mouth disease (HFMD) in Jiangyin from 2008 to 2023, and to provide a scientific basis for prevention and control strategies. Methods Joinpoint regression model was applied to analyze trends in reported incidence rate by year, month, gender and age. Results The annual incidence rate showed a significant upward trend from 2008 to 2018 (β=25.44, t=3.85, P<0.01), a non-significant downward trend from 2018 to 2021(β=-114.54, t=-1.35, P=0.22) and a non-significant upward trend from 2021 to 2023 (β=146.12, t=1.22, P=0.26). The overall annual incidence rate trend was higher in males than in females (P<0.01). The ≤2 years age group exhibited a non-significant increase in annual incidence (APC=94.72%, t=0.65, P=0.53), the 2-15 years age group showed a significant decline (APC=-45.03%, t=-5.33, P<0.01), and the ≥15 years age group displayed a significant decline (APC=-9.31%, t=-6.10, P<0.01). The monthly incidence rate significant increased from January to May (MPC=86.53%, t=2.71, P=0.03) and non-significant decreased from May to December (MPC=-15.18%, t=-1.69, P=0.13). Conclusions From 2008 to 2023, the annual incidence of HFMD in Jiangyin followed a "rise-decline-rise" pattern, with monthly incidence showing rapid increases followed by gradual declines. Age-specific trends were characterized by sharp rises, rapid declines, and long-tail effects. Prevention and control efforts should prioritize children aged ≤15 years, particularly males and those ≤2 years old, with heightened vigilance during summer months.

Key words: Hand-foot-mouth disease, Epidemic trend, Joinpoint regression model