METHODS: In 2020, human water contact sites (HWCSs) in the study area were geolocated and snail surveys were conducted. A parasitological and questionnaire cross-sectional baseline survey was implemented in 20 communities and their 16 primary schools between November 2020 and February 2021. Urine samples were collected at the school and household levels from individuals aged ≥ 4 years. Schistosoma haematobium infection was detected by urine filtration microscopy. Snail, parasitological and questionnaire-derived data were analyzed descriptively, spatially and with generalized estimated equation models.
RESULTS: The intermediate host snail Bulinus globosus was detected in 19.8% (33/167) of HWCSs. The overall S. haematobium prevalence was 1.2% (26/2196) in school-aged children and 0.8% (31/3893) in community members, with 0.2% (4/2196) and 0.1% (3/3893) heavy-intensity infections, respectively. Children who studied < 1 km away from HWCSs with B. globosus had significantly higher odds for a S. haematobium infection than those attending a school located > 2 km away (odds ratio [OR]: 5.0; 95% confidence interval [CI]: 2.3-11.1). Individuals living in a house located < 1 km away from HWCSs with B. globosus had higher odds than those residing in > 2 km distance (OR: 18.0; 95% CI: 2.9-111.0). Self-reported praziquantel treatment coverage was 83.2% (2015/2423) in schoolchildren in the mass drug administration (MDA) conducted in August 2020. Coverage among adult community members was 59.9% (574/958), but only 34.8% (333/958) took praziquantel correctly.
CONCLUSIONS: While the S. haematobium prevalence is very low in Pemba, there are many HWCSs with B. globosus situated close to schools or houses that pose a considerable risk of recrudescence. To maintain and accelerate the progress towards interruption of transmission, targeted and cost-effective interventions that are accepted by the community are needed; for example, snail control plus focal MDA, or test-and-treat in schools and households near infested waterbodies.
方法:2020年,对研究区域的人类水接触地点(HWCSs)进行了地理定位,并进行了蜗牛调查。在2020年11月至2021年2月期间,对20个社区及其16所小学进行了寄生虫学和问卷调查横断面基线调查。在学校和家庭层面从年龄≥4岁的个体收集尿样。通过尿液过滤显微镜检测血吸虫感染。蜗牛,寄生虫学和问卷衍生的数据进行了描述性分析,空间和广义估计方程模型。
结果:在19.8%(33/167)的HWCS中检测到中间寄主蜗牛球茎。在学龄儿童中,总的流菌感染率为1.2%(26/2196),在社区成员中为0.8%(31/3893),0.2%(4/2196)和0.1%(3/3893)的重强度感染,分别。与在距离>2km的学校上学的儿童相比,在距离HWCSs<1km的地方研究了球形芽孢杆菌的儿童感染S.omatomium的几率明显更高(优势比[OR]:5.0;95%置信区间[CI]:2.3-11.1)。居住在距离HWCSs<1km的房屋中的人与B.globosus的人相比,居住在距离>2km的人有更高的几率(OR:18.0;95%CI:2.9-111.0)。在2020年8月进行的大规模药物管理(MDA)中,小学生自我报告的吡喹酮治疗覆盖率为83.2%(2015/2423)。成人社区成员的覆盖率为59.9%(574/958),但只有34.8%(333/958)正确服用吡喹酮。
结论:虽然奔巴的嗜血杆菌患病率很低,在学校或房屋附近,有许多带有B.globosus的HWCSs存在相当大的复发风险。为了保持和加快传输中断的进程,需要社区接受的有针对性和具有成本效益的干预措施;例如,蜗牛控制加局灶性MDA,或在受感染水体附近的学校和家庭中进行测试和治疗。