Surveillance of soil-transmitted nematode infections in Zhenjiang City from 2006 to 2018

Abstract

Objective To understand the epidemic trend of soil-transmitted nematodiasis in Zhenjiang City from 2006 to 2018, so as to provide evidence for formulating targeted control measures.

Methods The permanent residents at ages of 3 years and greater and the immigrants who had lived in Zhenjiang City for more than one year were selected as the study subjects. Fecal samples were collected, and the soil-transmitted nematode eggs were detected in fecal samples with the modified Kato-Katz technique (three smears from one stool sample), while the children at ages of 12 years and lower were tested for Enterobius vermicularis eggs using the adhesive cellophane-tape perianal swab method. The prevalence and intensity of parasitic infections were estimated in Zhenjiang City each year from 2006 to 2018, and the data pertaining to the deworming for soil-transmitted nematode infections were collected during the study period.

Results A total of 202 880 person-times were subjected to stool examinations in Zhenjiang City from 2006 to 2018, and 946 persons were detected with soil-transmitted nematode infections, with a mean prevalence of 0.47%. The overall prevalence of human soil-transmitted nematode infections appeared a decline tendency ( P < 0.01), with a reduction from 1.10% in 2006 to 0.11% in 2018, and there was a region-specific overall prevalence ( P < 0.01), with the highest prevalence seen in Runzhou District (1.65%) and the lowest detected in New District (0.04%). The mean prevalence of human Ascaris lumbricoides, hookworm and Trichuris trichiura infections was 0.33%, 0.09% and 0.04% in Zhenjiang City, respectively, and showed a decline tendency year by year from 2006 to 2018 ( P < 0.01). Among all infections, mild infections were predominant. During the period from 2006 through 2018, a total of 45 427 children were examined in Zhenjiang City from 2006 to 2018, and 145 children were positive for E. vermicularis infections, with a mean prevalence of 0.32%. The prevalence of E. vermicularis infections decreased from 1.33% in 2006 to 0.22% in 2018 in children, and the overall prevalence appeared a decline tendency ( P < 0.01). A single parasite infection was predominant in soil-transmitted nematode infections (97.46%), and mixed infection of two parasites were mainly detected before 2007. A total of 535 089 person-times received deworming in Zhenjiang City from 2006 to 2018, and the rate of adverse events was 0.002%.

Conclusions Currently, the soil-transmitted nematode infection is at a low level in Zhenjiang City, and the overall prevalence of soil-transmitted nematode infections shows a decline tendency year by year. The surveillance and health education of soil-transmitted nematodiasis should be further intensified to consolidate the control achievements.

Abstract

［摘要］ 目的 了解2006–2018年镇江市土源性线虫病流行动态, 为制定有针对性的防治措施提供依据。 方法 2006–2018年以镇江市辖区内≥ 3周岁的常住居民及在本地居住满1年以上的外来人口作为监测对象, 采集其粪便样本, 采用改良加藤厚涂片法 (1粪3检) 检测粪便中土源性线虫虫卵, 12周岁及以下儿童加做透明胶纸肛拭法以检测蛲虫; 计算各年各虫种感染率和感染度, 并收集该期间内全市土源性线虫病驱虫服药数据。 结果 2006–2018 年全市累计粪检202 880人·次, 共检出土源线虫感染者946例, 平均感染率为0.47%; 人群总感染率从2006年的1.10%降至2018年的0.11%, 总体呈下降趋势 ( P < 0.01); 各市 (区) 总感染率存在差异 ( P < 0.01), 以润州区最高 (1.65%), 新区最低 (0.04%) 。全市人群蛔虫、钩虫、鞭虫平均感染率分别为0.33%、0.09%和0.04%, 且呈逐年下降趋势 ( P 均< 0.01); 感染均以轻度为主。2006–2018年全市累计检查45 427名儿童, 共检出蛲虫感染者145例, 平均感染率为0.32%; 儿童蛲虫感染率从2006 年的1.33%降至2018年的0.22%, 总体呈下降趋势( P < 0.01)。土源性线虫感染者以单虫种感染 (97.46%) 为主, 两虫混合感染主要集中在2007年前。2006–2018年全市累计驱虫服药535 089人·次, 人群不良反应出现率为0.002%。 结论 目前镇江市人群土源性线虫病已处于低流行状态, 感染率总体呈逐年下降趋势。后续应进一步加强土源性线虫病监测和健康教育, 以巩固防治成果。