Abstract: Objective　To analyze the trends in Oncomelania hupensis distribution in Wuhan City, Hubei Province from 2003 to 2022, so as to provide insights into precision schistosomiasis control. Methods　Data pertaining to O. hupensis snail survey in Wuhan City from 2003 to 2022 were collected. The trends in the proportion of areas with snail habitats, actual area with snail habitats, mean density of live snails and prevalence of Schistosoma japonicum infection in snails were evaluated in schistosomiasis⁃endemic areas of Wuhan City from 2003 to 2022 with the slope of trend curve (β), annual percent change (APC) and average annual percent change (AAPC) using a Joinpoint regression model. Results　During the period from 2003 through 2022, there were two turning points for the proportion of areas with snail habitats in Wuhan City in 2005 and 2015, with a rise during the period from 2003 to 2005 (β1 = 5.93, t = 1.280, P > 0.05), a decline from 2005 to 2015 (β2 = -0.88, t = -2.074, P > 0.05) and a rise from 2015 to 2022 (β3 = 1.46, t = -2.356, P < 0.05). During the period from 2003 through 2022, there were two turning points for the proportion of areas with snail habitats in islet endemic areas of Wuhan City in 2006 and 2015, with no significant differences in the trends from 2003 to 2006 (β1 = 4.64, t = 1.888, P > 0.05) or from 2006 to 2015 (β2 = -1.45, t = -2.143, P > 0.05), and with a tendency towards a rise from 2015 to 2022 (β3 = 2.04, t = -3.100, P < 0.05). During the period from 2003 through 2022, there were two turning points for the proportion of areas with snail habitats in inner embankment endemic areas of Wuhan City in 2012 and 2020, with a tendency towards a decline from 2003 to 2012 (β1 = -0.39, t = -4.608, P < 0.05) and with no significant differences in the trends from 2012 to 2020 (β2 = 0.03, t = 0.245, P > 0.05) and from 2020 to 2022 (β3 = 1.38, t = 1.479, P > 0.05). During the period from 2003 to 2022, the actual area with snail habitats all appeared a tendency towards a decline in Wuhan City, and in islet and inner embankment endemic areas of Wuhan City from 2003 to 2022 (AAPC = -2.39%, -5.75% and -2.35%, all P values < 0.05). The mean density of living snails reduced from 0.087 snails/0.1 m2 in 2003 to 0.027 snails/0.1 m2 in 2022 in Wuhan City, with a significant difference in the tendency towards the decline (APC = AAPC = -11.47%, P < 0.05). The annual mean decline rate of the mean density of living snails was 17.36% in outside embankment endemic areas of Wuhan City from 2003 to 2022 (APC = AAPC = -17.36%, P < 0.05), and there was no significant difference in the trends in the mean density of living snails in islet endemic areas of Wuhan City from 2003 to 2022 (APC = AAPC = -0.97%, P > 0.05). In addition, the prevalence of S. japonicum infection in snails appeared a tendency towards a decline in Wuhan City from 2003 to 2022 (APC = AAPC = -12.45%, P < 0.05). Conclusions　The proportion of areas with snail habitats, actual area with snail habitats, mean density of live snails and prevalence of S. japonicum infection in snails all appeared a tendency towards a decline in Wuhan City from 2003 to 2022. Intensified snail control, modification of snail habitats, shrinking of areas with snails and implementation of grazing prohibition in snail⁃infested settings are required, in order to facilitate the progress towards schistosomiasis elimination in Wuhan City.

Key words: Oncomelania hupensis, Schistosomiasis, Joinpoint regression model, Wuhan City

摘要： 目的　分析2003—2022年湖北省武汉市螺情变化趋势，为制定血吸虫病精准防控措施提供参考。方法　收集2003—2022年武汉市钉螺调查资料，以有螺面积查出比例、实有钉螺面积、活螺平均密度和钉螺血吸虫感染率等作为螺情分析指标，采用Joinpoint回归模型分析武汉市血吸虫病流行区各指标趋势变化，计算趋势曲线斜率（β）、年度变化百分比（annual percent change，APC）和平均年度变化百分比（average annual percent change，AAPC）以评价2003—2022年武汉市螺情数据变化趋势。结果　2003—2022年，武汉市有螺面积查出比例在2005年和2015年出现2个连接点，2003—2005年为上升阶段（β1 = 5.93，t = 1.280，P > 0.05）、2005—2015年为下降阶段（β2 = -0.88，t = -2.074，P > 0.05），变化趋势均无统计学意义；2015—2022年为上升阶段（β3 = 1.46，t = -2.356，P < 0.05）。2003—2022年，武汉市垸外洲滩亚型血吸虫病流行区有螺面积查出比例于2006年和2015年出现2个连接点，2003—2006年（β1 = 4.64，t = 1.888，P > 0.05）和2006—2015年（β2 = -1.45，t = -2.143，P > 0.05）变化趋势均无统计学意义，2015—2022年呈上升趋势（β3 = 2.04，t = -3.100，P < 0.05）。2003—2022年，武汉市垸内亚型血吸虫病流行区有螺面积查出比例在2012年和2020年出现2个连接点，2003—2012年呈下降趋势（β1 = -0.39，t = -4.608，P < 0.05）；2012—2020年（β2 = 0.03，t = 0.245，P > 0.05）和2020—2022年（β3 = 1.38，t = 1.479，P > 0.05）变化趋势均无统计学意义。2003—2022年，武汉市实有钉螺面积、垸内亚型和垸外洲滩亚型血吸虫病流行区实有钉螺面积均呈下降趋势（AAPC = -2.39%、-5.75%和-2.35%，P均< 0.05）。2003—2022年，武汉市活螺平均密度由0.087只/0.1 m2降至0.027只/0.1 m2，下降趋势有统计学意义（APC = AAPC = -11.47%，P < 0.05）。2003—2022年，武汉市垸外洲滩亚型流行区活螺平均密度年均下降17.36%（APC = AAPC = -17.36%，P < 0.05），垸内亚型流行区活螺平均密度变化趋势无统计学意义（APC = AAPC = -0.97%，P > 0.05）。2003—2022年，武汉市钉螺血吸虫感染率呈下降趋势（APC = AAPC = -12.45%，P < 0.05）。结论　2003—2022年，武汉市有螺面积查出比例、实有钉螺面积、活螺平均密度和钉螺血吸虫感染率均呈下降趋势。需进一步强化钉螺控制、改造钉螺孳生环境、压缩有螺面积、推进有螺地带禁牧等措施，以稳步推进武汉市血吸虫病消除工作。

关键词: 钉螺, 血吸虫病, Joinpoint回归模型, 武汉市