Analysis on surveillance results of clonorchiasis in Zhejiang Province from 2013 to 2022

doi:10.12140/j.issn.1000-7423.2024.04.007

Abstract

Abstract:

Objective To ascertain the endemic status of Clonorchis sinensis in Zhejiang Province. Methods From 2013 to 2017, one county (city, district) which had clonorchiasis cases reported before in Zhejiang Province was selected as the regular surveillance site and 3 townships in each site were selected for monitoring each year. No less than 100 permanent residents over age 3 in each township were selected as monitored objects. Venous blood samples were collected, and serum C. sinensis antibody was detected by enzyme-linked immunosorbent assay (ELISA). The positive rate of antibodies in the monitored objects was calculated. And questionnaire surveys were conducted on the factors affecting the infection of C. sinensis from 2013 to 2015. From 2018 to 2022, Ningbo City was selected as the fixed surveillance site and 7-9 counties (cities, districts) were selected as the mobile surveillance sites. Each surveillance site was divided into 5 areas as geographically at east, west, south, north and centre. In each area, one administrative village was randomly selected from one township for cluster sampling of no less than 200 permanent residents over age 3. Fecal samples (over 30 g) were collected for examining C. sinensis eggs using the modified Kato-Katz thick smear method. The infection rate of the monitored object was calculated. Freshwater fish from natural water were collected in regular surveillance sites from 2013 to 2017 and in the fixed surveillance site and a mobile surveillance site from 2018 to 2022. The infection of encysted metacercaria was detected by pressing method after identified the species. From 2018 to 2022, the fecal samples of cats, dogs and pigs were collected in surveillance sites which monitoring the intermediate hosts, and examined C. sinensis eggs using the modified Kato-Katz thick smear method. SPSS 19.0 was used for data statistical analysis. Infection rates were compared between groups using the chi-squared test. Results From 2013 to 2017, a total of 1 516 people were examined in Zhejiang Province and antibody positive rate was 2.51% (38/1 516). A total of 52 626 people were examined from 2018 to 2022. No C. sinensis eggs were found in fecal samples and the infection rate was 0 (0/52 626). The highest antibody positive rate of 6.00% (18/300) was seen in Panan County. The antibody positive rate in different surveillance sites was statistically significant (χ² = 21.212, P < 0.01). The highest antibody positive rate of 8.82% (6/68) was seen in the age 3-17 group. The antibody positive rate in different age groups was statistically significant (χ² = 13.105, P < 0.05). The infection rate of C. sinensis in freshwater fish from 2013 to 2022 were 12.56% (476/3 791). The highest infection rate of 33.47% (84/251) was seen in Ninghai County in 2018. The infection rate in different surveillance sites was statistically significant (χ² = 242.727, P < 0.01). The highest infection rate of 75.00% (21/28) was seen in Acanthobrama simoni. The infection rate in different fish species was statistically significant (χ² = 174.750, P < 0.01). The infection rate of reservoir host was 1.17% (3/257). Conclusion The infection rate of C. sinensis in human population was considerably low in surveillance sites in Zhejiang Province, but the infected intermediate hosts and reservoir hosts still remained, which poses a potential epidemic risk and requires strengthened surveillance, prevention and health education.

Key words: Clonorchis sinensis, Intermediate host, Reservoir host, Infection rate, Surveillance

CLC Number:

R532.23

CHAI Yingzhi, CHEN Hualiang, YU Kegen, ZHANG Xuan, WANG Xiaoxiao, ZHANG Jiaqi, XU Wenjie, RUAN Wei. Analysis on surveillance results of clonorchiasis in Zhejiang Province from 2013 to 2022[J]. CHINESE JOURNAL OF PARASITOLOGY AND PARASITIC DISEASES, 2024, 42(4): 469-474.

Figures/Tables 5

Table 1

Table 2

Table 3

Table 4

Table 5

References 16

[1]	Lai DH, Hong XK, Su BX, et al. Current status of Clonorchis sinensis and clonorchiasis in China[J]. Trans R Soc Trop Med Hyg, 2016, 110(1): 21-27.
[2]	Wang KY, Shu HF, Fang YY, et al. Data analysis of clonorchiasis surveillance in high endemic areas of Guangdong Province in 2016-2020[J]. Chin J Parasitol Parasit Dis, 2022, 40(5): 629-634. (in Chinese)
	(王可艺, 舒黄芳, 方悦怡, 等. 2016—2020年广东省华支睾吸虫病高流行地区人群感染监测分析[J]. 中国寄生虫学与寄生虫病杂志, 2022, 40(5): 629-634.) doi: 10.12140/j.issn.1000-7423.2022.05.010
[3]	Tang ZL, Huang Y, Yu XB. Current status and perspectives of Clonorchis sinensis and clonorchiasis: epidemiology, pathogenesis, omics, prevention and control[J]. Infect Dis Poverty, 2016, 5: 71.
[4]	Xu LQ, Chen YD, Sun FH, et al. A national survey on current status of the important parasitic diseases in human population[J]. Chin J Parasitol Parasit Dis, 2005, 23(S1): 332-340. (in Chinese)
	(许隆祺, 陈颖丹, 孙凤华, 等. 全国人体重要寄生虫病现状调查报告[J]. 中国寄生虫学与寄生虫病杂志, 2005, 23(S1): 332-340.)
[5]	Bouvard V, Baan R, Straif K, et al. A review of human carcinogens: Part B―biological agents[J]. Lancet Oncol, 2009, 10(4): 321-322.
[6]	Qian MB, Chen YD, Liang S, et al. The global epidemiology of clonorchiasis and its relation with cholangiocarcinoma[J]. Infect Dis Poverty, 2012, 1: 4.
[7]	Wang Q, Xu J, Xia ZG, et al. Epidemic status and key tasks for the control and elimination of key parasitic diseases in China[J]. Chin J Parasitol Parasit Dis, 2024, 42(1): 1-7. (in Chinese)
	(王强, 许静, 夏志贵, 等. 我国重点寄生虫病疫情形势及防控工作重点[J]. 中国寄生虫学与寄生虫病杂志, 2024, 42(1): 1-7. doi: 10.12140/j.issn.1000-7423.2024.01.001
[8]	Gu MX, Yu YJ, Zhang JC, et al. Current status and influencing factors of Clonorchis sinensis infection in rural areas of Ninghai County in Zhejiang Province[J]. Chin J Parasitol Parasit Dis, 2017, 35(6): 585-587. (in Chinese)
	(顾敏霞, 俞垚军, 章金川, 等. 浙江省宁海县华支睾吸虫感染现状及其影响因素的调查[J]. 中国寄生虫学与寄生虫病杂志, 2017, 35(6): 585-587.)
[9]	Yang TT, Yao LN, Yao SR, et al. Assessment of Clonorchis sinensis epidemic trends and its natural epidemic focus in northern area of Zhejiang Province[J]. Zhejiang J Prev Med, 2011, 23(5): 17-18, 22. (in Chinese)
	(杨婷婷, 姚立农, 姚顺荣, 等. 浙北地区华支睾吸虫疫源地调查及传播趋势评估[J]. 浙江预防医学, 2011, 23(5): 17-18, 22.)
[10]	Chen HL, Wang DB, Luo XJ, et al. Prevalence of Clonorchis sinensis infection in Western Area of Zhejiang Province[J]. Dis Surveillance, 2013, 28(6): 499-502. (in Chinese)
	(陈华良, 汪德兵, 骆小君, 等. 浙江省西部丘陵地区华支睾吸虫感染现状研究[J]. 疾病监测, 2013, 28(6): 499-502.)
[11]	Xu JF, Yin BK, Wu EM, et al. Investigation on infection status of clonorchiasis in Jiangmen City from 2009 to 2010[J]. J Med Pest Contr, 2012, 28(9): 952-954. (in Chinese)
	(许坚锋, 尹本康, 吴尔明, 等. 江门市区2009—2010年人群华支睾吸虫病感染状况调查[J]. 医学动物防制, 2012, 28(9): 952-954.)
[12]	Wan XL, Zhang WW, Jiang ZH, et al. Investigation on the status of human important parasitic disease in Guangxi in 2015[J]. China Trop Med, 2019, 19(1): 19-22, 30. (in Chinese)
	(万孝玲, 张伟尉, 蒋智华, 等. 广西2015年人体重点寄生虫感染现状调查[J]. 中国热带医学, 2019, 19(1): 19-22, 30.) doi: 10.13604/j.cnki.46-1064/r.2019.01.05
[13]	Chen YD, Zhou CH, Zhu HH, et al. National survey on the current status of important human parasitic diseases in China in 2015[J]. Chin J Parasitol Parasit Dis, 2020, 38(1): 5-16. (in Chinese)
	(陈颖丹, 周长海, 朱慧慧, 等. 2015年全国人体重点寄生虫病现状调查分析[J]. 中国寄生虫学与寄生虫病杂志, 2020, 38(1): 5-16.) doi: 10.12140/j.issn.1000-7423.2020.01.002
[14]	Zhang CP, Chen DZ, Li Q. Analysis of monitoring results of key parasitic diseases in Jinhu County from 2016 to 2020[J]. Appl Prev Med, 2021, 27(4): 352-353, 356. (in Chinese)
	(张翠萍, 陈德珍, 李倩. 2016—2020年金湖县重点寄生虫病监测结果分析[J]. 应用预防医学, 2021, 27(4): 352-353, 356.)
[15]	Zhu H, Sun CS, Wang QZ, et al. Survey of Clonorchis sinensis infection in freshwater fish in some areas in Anhui Province[J]. J Trop Dis Parasitol, 2022, 20(6): 325-329. (in Chinese)
	(朱海, 孙成松, 汪奇志, 等. 安徽省部分地区淡水鱼华支睾吸虫感染状况调查分析[J]. 热带病与寄生虫学, 2022, 20(6): 325-329.)
[16]	Dai SM, Yu Q, Ma XJ, et al. Prevalence of Clonorchis sinensis infections in freshwater fish in mainland China: a meta-analysis[J]. Chin J Schisto Control, 2022, 34(1): 16-27, 35. (in Chinese)
	(戴思敏, 余晴, 马晓疆, 等. 中国大陆淡水鱼华支睾吸虫感染率的meta分析[J]. 中国血吸虫病防治杂志, 2022, 34(1): 16-27, 35.)

年份 Year	监测点 Surveillance site	监测人数 No. surveyed	抗体阳性数/例 No. positive	抗体阳性率/% Positive rate/%
2013	磐安县 Panan County	300	18	6.00
2014	定海区 Dinghai County	314	4	1.27
2015	文成县 Wencheng County	302	2	0.66
2016	嘉善县 JiashanCounty	300	6	2.00
2017	嘉善县 JiashanCounty	300	8	2.67
合计 Total		1 516	38	2.51

特征 Feature	监测人数 No. surveyed	抗体阳性数/例 No. of positive	抗体阳性率/% Positive rate/%
性别 Gender
男 Male	385	6	1.56
女 Female	531	18	3.39
年龄组/岁 Age group/Year
3~17	68	6	8.82
18~30	91	3	3.30
31~40	128	4	3.13
41~50	183	2	1.09
51~60	185	3	1.62
61~70	161	4	2.48
> 70	100	2	2.00
文化程度 Education
文盲、半文盲 Illiteracy, semiliterate	204	4	1.96
小学 Primary school	257	6	2.33
初中 Junior high school	281	8	2.85
高中/中专 High school, technical secondary school	118	2	1.69
大专及以上 College or above	56	4	7.14
职业 Occupation
农民 Farmer	318	7	2.20
干部 Official	18	1	5.56
工人 Worker	74	4	5.41
学生 Student	64	4	6.25
农民工 Migrant worker	64	0	0
个体户及私营企业主 Individual businesses, private businessman	156	3	1.92
公司职员 Office worker	17	1	5.88
商业/服务业员工 Waiter	143	2	1.40
医务人员 Medical staff	20	2	10.00
无业人员 Unemployed	39	0	0
其他Others	3	0	0
家庭年收入 Annual household income
< 5 000	126	5	3.97
5 000~10 000	165	4	2.42
10 001~50 000	323	9	2.79
> 50 000	168	4	2.38
不详 Not quite clear	134	2	1.49

年份 Year	监测点 Surveillance site	监测数/尾 No. surveyed/tail	感染数/尾 No. infected/tail	感染率/% Infection rate/%
2013	磐安县 Panan County	361	37	10.25
2014	定海区 Dinghai County	201	49	24.38
2015	文成县 Wencheng County	238	0	0
2016	嘉善县 Jiashan County	210	29	13.81
2017	嘉善县 Jiashan County	279	45	16.13
2018	宁海县 Ninghai County	251	84	33.47
	缙云县 Jinyun County	250	28	11.2
2019	宁海县 Ninghai County	251	6	2.39
	桐庐县 Tonglu County	250	3	1.2
2020	宁海县 Ninghai County	250	54	21.6
	德清县 Deqing County	250	69	27.6
2021	宁海县 Ninghai County	250	60	24
	天台县 Tiantai County	250	0	0
2022	宁海县 Ninghai County	250	12	4.8
	临海市 Linhai County	250	0	0
合计 Total		3 791	476	12.56

鱼种 Fish species	监测数/尾 No. surveyed/tail	感染数/尾 No. infected/tail	感染率/%Infection rate/%
麦穗鱼 Pseudorasbora parva	1 184	187	15.79
光唇鱼 Acrossocheilus fasciatus	209	5	2.39
鰟鮍鱼 Rhodeus sinensis Gunther	256	45	17.58
鲫鱼 Carassius auratus (Linnaeus)	113	9	7.96
白条鱼 Hemiculter leucisculus	241	29	12.03
泥鳅 Misgurnus anguillicaudatus	61	0	0
黄鳝 Monopterus albus	1	0	0
餐鲦鱼 Hemiculter leucisculus	1 460	175	11.99
黄颡鱼 Pelteobagrus fulvidraco	33	0	0
花溪鱼 Sarcocheilichthys sinensis	15	0	0
草鱼 Ctenopharyngodon idella	9	0	0
棒花鱼 Abbottina rivularis	159	3	1.89
鳊鱼 Parabramis pekinensis	3	1	1/3
鲢鱼 Hypophthalmichthys molitrix	4	0	0
逆鱼 Acanthobrama simoni	28	21	75.00
其他 Others	15	1	1/15
合计 Total	3 791	476	12.56