Abstract: Objective To investigate the density and seasonal variation of ticks captured from human settlement and surroundings in China, and to provide a basis for risk assessment and scientific prevention and control of ticks and tick-borne diseases. Methods The tick surveillance data in 2018 were collected from 53 surveillance sites of the National Vectors Surveillance in China. The dominant species of ticks were analyzed, and the density and seasonal variation of ticks were compared between different hosts, habitats, and provinces. Results Haemaphysalis longicornis was detected most frequently in 2018. Among the host animals, sheep and cattle had the highest tick index, and the tick index of urban pet dogs increased from 0.04 in 2017 to 0.15 in 2018. The tick density in surroundings of villages was higher than that in scenic areas. The highest index of on-host ticks was observed in July, and the highest density of questing ticks was observed in August; their secondary peaks were observed in April to May, and on-host ticks had an additional peak in September. Conclusion Haemaphysalis longicornis was the predominat species of ticks in human habitats and surroundings in China, sheep and cattle were dominant host animals, and surroundings of villages are the dominant habitat of ticks. There were 3 peaks in the curve of the index of on-host ticks and 2 peaks in the curve of the density of questing ticks. There was an increase in the tick index of urban pet dogs from 2017 to 2018. These results suggest that tick prevention and control should be strengthened for rural domestic animals and in surroundings of villages, as well as in early spring and the middle of the year. Tick infection in urban pets should not be neglected.

Key words: Tick, Surveillance, Host animal, Habitat, Seasonal variation

摘要： 目的 了解我国人居环境周边常见蜱类的密度和活动规律，为蜱侵害及蜱传疾病的风险评估和科学有效防控提供依据。方法 收集整理2018年我国病媒生物监测体系中53个监测点的蜱类监测数据，分析优势蜱种类，比较不同生境和宿主、不同省份蜱类密度差异及季节消长规律。结果 2018年检获蜱种中长角血蜱检获次数最多；不同宿主动物中，羊、牛的蜱指数较高，城市宠物犬的蜱指数从2017年的0.04上升到0.15；农村外环境捕获的蜱密度高于景区环境；开展监测的不同月份中，7月寄生蜱指数最高，游离蜱则以8月密度最高，两者的次波峰在4-5月，寄生蜱在9月还有1个小高峰。结论 我国人居环境周边长角血蜱较为常见；牛、羊是监测宿主中的优势宿主动物，农村外环境是蜱的优势生境；寄生蜱指数全年呈三峰曲线，游离蜱密度呈双峰曲线；城镇宠物犬的蜱指数较2017年有所升高，提示要加强对农村家养动物及其活动环境早春和年中的蜱类防制，城市宠物染蜱情况不容忽视。

关键词: 蜱, 监测, 宿主动物, 生境类型, 季节消长