Department of Parasitology and Medical Entomology, School of Public Health and Social Sciences, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania.
Department of Zoology and Wildlife Conservation, College of Natural and Applied Sciences, University of Dar es Salaam, Dar es Salaam, Tanzania.
PLoS Negl Trop Dis. 2024 Sep 6;18(9):e0012470. doi: 10.1371/journal.pntd.0012470. eCollection 2024 Sep.
Epidemiological evidence suggests that Onchocerca volvulus is associated with epilepsy, although the exact pathophysiological mechanism is unknown. Mahenge is an endemic focus of onchocerciasis, with the longest-running ivermectin treatment intervention in Tanzania. We assessed the prevalence of onchocerciasis and epilepsy after 25 years of control using ivermectin.
This was a population-based cross-sectional study in 34 villages in Mahenge in 2021. Community health workers conducted door-to-door household surveys to enumerate the population and screen for individuals suspected of epilepsy using a standardised questionnaire. Trained physicians confirmed epilepsy. Children aged 6-11 years were screened for onchocerciasis antibodies using the Ov16 rapid test. Villages were stratified into three altitude levels (low [<400], medium [400-950], and high [>950 meters above sea level]) as a proxy for rapids, which black flies favour for breeding sites. Incidence of epilepsy was estimated as a ratio of new cases in the year preceding the survey per 100,000 population.
56,604 individuals (median age 20.2 years, 51.1% females) were surveyed. Onchocerciasis prevalence in children was 11.8% and was highest in villages at medium (21.7%) and lowest in low altitudes (3.2%), p<0.001. Self-reported use of ivermectin was 88.4%. Epilepsy prevalence was 21.1 (95%CI: 19.9-22.3) cases per 1000 persons and was highest in medium (29.5%) and lowest in the lowlands (12.7%). The odds ratio (OR) of having epilepsy was significantly higher in females (OR = 1.22, 95%CI: 1.08-1.38), middle altitudes (OR = 2.34 [95%CI: 2.04-2.68]), and in individuals positive for OV16 (OR = 1.98 [95%CI:1.57-2.50]). The incidence of epilepsy a year before the survey was 117 (95%CI: 99.7-160.4) cases per 100,000 person-years.
Despite ivermectin use for 25 years, the prevalence of onchocerciasis and epilepsy remains high. It is crucial to strengthen bi-annual ivermectin treatment and initiate interventions targeting vectors to control onchocerciasis and epilepsy in the area.
流行病学证据表明，旋盘尾丝虫与癫痫有关，尽管确切的病理生理机制尚不清楚。马亨盖是盘尾丝虫病的流行焦点，也是坦桑尼亚运行时间最长的伊维菌素治疗干预地区。我们评估了使用伊维菌素 25 年后的盘尾丝虫病和癫痫的流行情况。
这是 2021 年在马亨盖 34 个村庄进行的一项基于人群的横断面研究。社区卫生工作者挨家挨户进行家庭调查，以对人口进行计数，并使用标准化问卷对疑似癫痫的个体进行筛查。经过培训的医生确认了癫痫。6-11 岁的儿童使用 Ov16 快速检测试剂盒筛查盘尾丝虫病抗体。村庄根据海拔高度（低[<400]、中[400-950]和高[>950 米]）分为三个层次，这是因为黑蝇喜欢在这些地方繁殖。癫痫的发病率估计为前一年每 10 万人新发病例的比值。
共调查了 56604 人（中位数年龄 20.2 岁，51.1%为女性）。儿童中盘尾丝虫病的流行率为 11.8%，中海拔（21.7%）最高，低海拔（3.2%）最低，p<0.001。自我报告使用伊维菌素的比例为 88.4%。癫痫的患病率为 21.1（95%CI：19.9-22.3）例/1000 人，中海拔（29.5%）最高，低海拔（12.7%）最低。女性（OR=1.22，95%CI：1.08-1.38）、中海拔（OR=2.34[95%CI：2.04-2.68]）和 OV16 阳性（OR=1.98[95%CI：1.57-2.50]）的个体癫痫发病的比值比（OR）显著更高。调查前一年癫痫的发病率为每 10 万人年 117（95%CI：99.7-160.4）例。
尽管使用伊维菌素 25 年，但盘尾丝虫病和癫痫的流行率仍然很高。必须加强每半年一次的伊维菌素治疗，并采取针对病媒的干预措施，以控制该地区的盘尾丝虫病和癫痫。
