2015-2019年湖南省国家血吸虫病监测点疫情分析

目的分析湖南省国家血吸虫病监测点疫情变化趋势,为制定全省血吸虫病消除策略提供依据。方法按照《全国血吸虫病监测方案(2014年版)》要求,在湖南省41个血吸虫病流行县(市、区)设国家血吸虫病监测点。2015-2019年开展本地人群、流动人群、家畜血吸虫感染监测和螺情监测,对各年病情和螺情数据进行分析。结果 2015-2019年,湖南省国家血吸虫病监测点本地居民和流动人口血吸虫病血检阳性率分别为2.57%和1.56%,均呈逐年降低趋势,男性血检阳性率均高于女性(P <0.01);5年间,洲滩型、洲垸型、垸内型和丘陵型4种流行区人群血检阳性率均呈逐年下降趋势。2015-2019年,2015年和2016年分别检出44例和19例本地人群粪检阳性、5例和1例流动人口粪检阳性。5年累计监测家畜9 346头·次,2015、2016年检出粪检阳性家畜6头(均为牛)。2015-2019年,共进行钉螺调查1.55亿m2,活螺平均密度总体呈逐年下降趋势,2019年较2015年下降45.79%;5年间未查获血吸虫感染性钉螺;采用环介导等温扩增技术(LAMP)检测混合钉螺样本1 469份,2015、2017年分别检出阳性混合样本1份和5份。结论湖南省血吸虫病疫情总体呈下降趋势,人、畜血吸虫感染率处于较低水平;但血吸虫病传播风险依然存在,今后应加强健康教育、加大流动人群查病力度、进一步完善血吸虫病监测体系,以巩固已取得的防治成果。

Endemic situation of schistosomiasis in national surveillance sites of Hunan Province from 2015 to 2019

Objective To analyze the changes in the endemic situation of schistosomiasis in national surveillance sites of Hu-nan Province, so as to provide scientific basis for the development of the schistosomiasis elimination programme in the province.Methods According to the requirements of the National Guidelines for Schistosomiasis Surveillance in China(2014 version), atotal of 41 national schistosomiasis surveillance sites were assigned in all disease-endemic counties(districts) across Hunan Prov-ince. During the period between 2015 and 2019, Schistosoma japonicum infections were monitored in local residents, mobile pop-ulations and livestock, and snail status was monitored. The morbidity due to schistosomiasis and snail status was compared be-tween years.Results The sero-prevalence of S. japonicum infections was 2.57% and 1.56% in local residents and mobile popu-lations in national surveillance sites of Hunan Province from 2015 to 2019, respectively, and the sero-prevalence appeared a ten-dency towards a decline over years. A higher sero-prevalence rate of S. japonicum infections was seen in men than in women(P <0.01). During the 5-year study period, the sero-prevalence rate of human S. japonicum infections appeared a tendency towards adecline in the marshland, embankment, inner embankment and hilly types of endemic areas over years. There were 44 and 19 egg-positives detected in local residents and 5 and 1 egg-positives in mobile populations in 2015 and 2016 respectively. A total of9 346 domestic animals were monitored from 2015 to 2019, and 6 egg-positives were detected in 2015 and 2016(all were bo-vine). A total of 0.155 billion m2 settings were surveyed from 2015 to 2019, and the mean density of living snails appeared a ten-dency towards a decline over years, with a 45.79% reduction in 2019 as compared to 2015. However, no S. japonicum infectionswere identified in snails during the 5-year period. A total of 1 469 mixed snail samples were detected using loop-mediated isother-mal amplification(LAMP), and 6 positive snail samples were identified in 2015(one sample) and 2017(5 samples).Conclu Conclusions The overall endemic situation of schistosomiasis appears a tendency towards a decline in Hunan Province, and the preva-lence of S. japonicum infections is at a low level in humans and livestock;however, there is still a risk of schistosomiasis transmis-sion. Improvements of health education, intensification of schistosomiasis examinations in mobile populations and reinforcementof the surveillance-response system is required to consolidate the achievements of schistosomiasis control in Hunan Province.