Abstract: Objective: A retrospective analysis of the epidemiological characteristics and trends of newly diagnosed leprosy cases in Suining City since its establishment, so as to provide scientific evidence for optimizing the local leprosy prevention and control strategies. Methods: Newly diagnosed leprosy cases in Suining City from 1985 to 2024 were collected and compiled from the National STD and Leprosy Prevention and Control Management Information System, a subsystem of the China Information System for Disease Control and Prevention.The study period was divided into three phases: the basic elimination phase (1985-2000), the achievement consolidation phase (2001-2010), and the hazard elimination phase (2011-2024). Descriptive statistics, the chi-square test were adopted to analyze the epidemiological characteristics and their changes of newly diagnosed leprosy cases in Suining City across different prevention and control stages. Results: From 1985 to 2024, a total of 78 new leprosy cases were identified in Suining City, with an average annual detection rate of 0.06 per 100,000 people. During the study period, the annual average detection rate of new leprosy showed a downward trend (χ2 trend = 10.276, P = 0.001), with an average annual decline rate of 4.82%.The delayed case detection rates during the period of basic elimination, consolidation of achievements, and hazard elimination were 74.42%,43.48%, and 50.00%, respectively; the proportions of neurological damage were 81.40%,52.17%, and 58.33%; the rates of grade 2 deformities were 11.63%,0.00%, and 25.00%; and the case loss-to-follow-up rates were 16.28%,26.09%, and 8.33%, respectively. Case detection methods were predominantly passive during the periods of basic elimination and hazard elimination, while active detection was the primary approach during the consolidation of achievements phase (χ2=10.756, P=0.005). Conclusion: The leprosy prevention and control work in Suining City has achieved remarkable results. At present, the city's leprosy epidemic is in a state of low prevalence, with the case loss-to-follow-up rate and case detection delay dropping significantly.

Key words: leprosy, intervention stage, epidemiological characteristics, discovery delay, Suining