目的 分析2014—2025年云南德宏间日疟的复发趋势，为疟疾防制策略提供依据。方法 采用回顾性横断面研究，从国家疾病预防控制信息系统收集2014—2025年德宏间日疟报告病例信息，使用其查重功能核查复发病例计算复发率，采用Shapiro-Wilk检验和Levene检验分别进行正态性和方差齐性检验，采用独立样本t检验分析2014—2019年复发率和2020—2025年复发率差异。采用中断时间序列（ITS）分析以“2020年云南省改用WHO捐赠的塞浦路斯产的伯氨喹根治间日疟和卵型疟”为干预断点的复发率变化趋势。结果 2014—2025年德宏共报告间日疟2 485例，其中境外输入2 454例（占98.75%），复发79例，复发率为3.18%（79/2 485）。2020—2025年复发率为（4.60 ± 1.82）%，与2014—2019年的（1.64 ± 1.40）%差异有统计学意义（t = -3.158，P < 0.05）；2020—2025年复发率较2014—2019年平均升高2.96%[95%置信区间（CI）：0.87%~5.04%]。2014—2025年德宏间日疟复发率总体呈波动变化，2020年为明显时间断点。ITS回归模型拟合结果显示，中心化时间变量、干预变量、交互项、延迟变量的回归系数分别为-0.363（95% CI：-1.890~1.163）、5.115（95% CI：-1.076~11.307）、0.078（95% CI：-1.840~1.996）、-0.069（95% CI：-0.872~0.734），差异均无统计学意义（t = -0.582、2.021、0.099、-0.210，P > 0.05）。提示2014—2019年和2020—2025年德宏间日疟复发率均呈下降趋势，且2020年干预节点复发率出现即时上升，2020年后复发率的下降趋势略有减缓。结论 德宏间日疟复发率变化趋势与更换国外产伯氨喹无关，复发率维持低水平，无需更换根治方案，但需加强监测。

Objective To analyze the trends in relapse of Plasmodium vivax malaria in Dehong, Yunnan from 2014 to 2025, so as to provide insights into formulation of malaria control strategies. Methods A retrospective cross-sectional study was performed to analyze the trend of relapse rate of Plasmodium vivax. All data pertaining to reported P. vivax malaria cases in Dehong from 2014 to 2025 were extracted from the China Disease Control and Prevention Information System. Relapsed cases were verified with the duplicate checking function, and the relapse rate was calculated. Shapiro-Wilk test was used to test for normality and Levene’s test was used to test for homogeneity of variances. Independent-sample t-test was employed to compare the differences in relapse rates during the period between 2014-2019 and 2020-2025. In addition, the trends in the relapse rate were examined using interrupted time series (ITS) analysis with the intervention breakpoint of “switching to WHO-donated and Cyprus-produced primaquine for radical treatment of P. vivax and P. ovale malaria in Yunnan Province in 2020”. Results A total of 2 485 P. vivax malaria cases were reported in Dehong from 2014 to 2025, including 2 454 overseas imported cases (98.75%) and 79 relapsed cases, with an overall relapse rate of 3.18% (79/2 485). There was a significant difference in the relapse rate between 2020 and 2025 [(4.60 ± 1.82)%] and between 2014 and 2019 [(1.64 ± 1.40)%] (t = -3.158, P < 0.05), and an average increase of 2.96% [95% confidence interval (CI): 0.87% to 5.04%, P < 0.05] was seen in the relapse rate during the period from 2020 to 2025 relative to from 2014 to 2019. From 2014 to 2025, the vivax malaria relapse rate in Dehong fluctuated generally, and 2020 was an obvious breakpoint in the time series. ITS regression analysis revealed that the regression coefficients for the centering time variable, intervention variable, interaction term, and lagged variable were -0.363 (95% CI: -1.890 to 1.163; t = -0.582, P > 0.05), 5.115 (95% CI: -1.076 to 11.307; t = 2.021, P > 0.05), 0.078 (95% CI: -1.840 to 1.996; t = 0.099, P > 0.05), -0.069 (95% CI: -0.872 to 0.734; t = -0.210, P > 0.05), indicating a tendency towards a decline in the relapse rate of P. vivax malaria in Dehong during the period from 2014 to 2019 and from 2020 to 2025. In addition, the relapse rate exhibited an immediate increase at the intervention point in 2020, and the tendency towards a decline in the relapse rate slowed slightly after 2020. Conclusion The changing trends in the relapse rate of P. vivax malaria is not associated with the replacement of foreign countries-produced primaquine in Dehong. The relapse rate remains low, and there is no need to change the radical cure regimen. However, enhanced surveillance is required.