Investigation on the contamination status of Echinococcus eggs in environmental samples in Longbaotan, Qinghai Province in 2023

doi:10.3969/j.issn.1672-2302.2024.03.007

Abstract

Abstract:

Objective To investigate the environmental contamination status of Echinococcus eggs in Longbaotan area of Qinghai Province for evidence to formulate targeted measures in controlling echinococcosis. Methods From March to April 2023, we collected different types of environmental samples, including canine feces, animal hair, water, soil, grass and food, from the dog households, main streets in the villages and wild areas. PCR technology was used to detect Echinococcus eggs in the samples from different sources, and the detection rate of eggs was compared. ArcGIS software combined with ASTER GDEM elevation data was used to make the elevation map of sample distribution. Results A total of 400 environmental samples were harvested. The total detection rate of Echinococcus eggs was 13.50% (54/400). Of the samples obtained, 138 were canine feces, 75 animal hair, 13 water, 114 soil, 37 grass and 23 food, in which the detection rate of Echinococcus eggs was 30.43% (42/138), 5.33% (4/75), 15.38% (2/13), 5.26% (6/114), 0 (0/37) and 0 (0/23), respectively. Among 138 aliquots of canine faeces, the animals hosts were failed to be identified in the 19 aliquots of wild canine feces by PCR. Of the other 119 samples, the detection rates of Echinococcus egg in the feces of dog, Tibetan fox and red fox were 11.29% (7/62), 48.84% (21/43) and 50.00% (7/14), respectively, with significant difference (χ²=20.481, P<0.05). The egg detection rates of Echinococcus granulosus, E. multilocularis and E. shiquicus were 2.17% (3/138), 18.12% (25/138) and 16.67% (23/138), respectively, with significant difference (χ²=19.858, P<0.05). In the 75 animal hair samples, the detection rates of Echinococcus egg in dog hair and cow hair were 6.06% (4/66) and 0 (0/9), respectively, with no significant difference (P>0.05). Of the 13 water samples, the detection rates of Echinococcus egg in wild river and streams, village well water and stagnant water were 20.00% (2/10), 0 (0/2) and 0 (0/1), respectively, with no significant difference (P>0.05). Among the 114 soil samples, the detection rates of Echinococcus egg in dog households, main streets and fields were 15.00% (3/20), 15.00% (3/20) and 0 (0/74), respectively, with significant difference (P<0.05). The eggs detected in animal hair, water and soil samples were from E. granulosus. In terms of distribution of the eggs, the feces of canines detected with eggs was highly concentrated in areas near field roads, and there was no obvious concentration trend in the samples of eggs detected in other environments. Conclusion The environmental contamination of Echinococcus eggs in Longbaotan area is serious and widely distributed. Our findings suggest that it is necessary to continue to take prevention and control measures such as deworming of dogs (especially unleashed dogs) and wild infectious sources (foxes) to reduce the pollution of eggs and the transmission risk of echinococcosis.

Key words: Echinococcus, Echinococcosis, Eggs, Environment, Contaminate, Longbaotan

CLC Number:

R383.33

SUN Chenqing, YANG Shijie, HAN Shuai, WANG Xu, CHEN Junhu, HONG Yang, ZHANG Ting, ZHANG Renjie, HE Gengcheng, MA Xiao, ZHAO Cunzhe, GONG Chunhua, WANG Jipeng, ZHOU Xiaonong. Investigation on the contamination status of Echinococcus eggs in environmental samples in Longbaotan, Qinghai Province in 2023[J]. Journal of Tropical Diseases and Parasitology, 2024, 22(3): 164-171.

Figures/Tables 6

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引物类型	鉴定物种	引物名称	序列（5'-3'）	产物长度（bp）
通用引物	脊椎动物	16S	F: GAGAAGACCCTATGGAGC	380
	脊椎动物	16S	R: ATAGAAACCGACCTGGAT	380
	绦虫纲	874	F: TTGAATTTGCCACGTTTGAATGC	874
		874	R: GAACCTAACGACATAACATAATGA	874
		JP	F: AGATTCGTAAGGGGCCTAATA	400
		JP	R: ACCACTAACTAATTCACTTTC	400
		JB	F: TTTTTTGGGCATCCTGAGGTTTAT	366
		JB	R: TAAAGAAAGAACATAATGAAAATG	366
特异性引物	细粒棘球绦虫	Eg	F: GTTTTTGGCTGCCGCCAGAAC	226
		Eg	R: AATTAATGGAAATAATAACAAACTTAATCAACAAT	226
		Eg157	F: ATTCCACACCAGCCCTAAC	175
		Eg157	R: CCTCCCTTCTCTTCCCTACA	175
		Eg174	F: CCTCGCATCCTGAGCATAAC	169
		Eg174	R: TGGTGTTGGTCTCCTTGGT	169
	多房棘球绦虫	Em	F: TAGTTGTTGATGAAGCTTGTTG	207
		Em	R: ATCAACCATGAAAACACATATACAAC	207
		EmC	F: GTCATATTTGTTTAAGTATAAGTGG	243
		EmC	R: CACTCTTATTTACACTAGAATTAAG	243
		Em175	F: GCTGTGAGGTGCTGCTAC	157
		Em175	R: CGAGGAGGCGACGATAAC	157
		Em169	F: AGTGGTAGCAACGAGGTC	174
		Em169	R: CGGCATAACGGCAGTAAC	174
	石渠棘球绦虫	Es	F: TTATTCTCAGTCTCGTAAGGGTCCG	442
		Es	R: CAATAACCAACTACATCAATAATT	442
		EsC	F: GTTGGTTACGTTACCGGTT	420
		EsC	R: TCTTATTAACATTTGAATTCAAC	420

粪便分类	样本数（份）	检出数（份）	检出率（%）	E.g虫卵		E.m虫卵		E.s虫卵
粪便分类	样本数（份）	检出数（份）	检出率（%）	检出数（份）	检出率（%）	检出数（份）	检出率（%）	检出数（份）	检出率（%）
犬粪便	62	7	11.29	1	1.61	5	8.06	2	3.23
拴养犬	50	3	6.00	0	0	2	4.00	1	2.00
未拴养犬	12	4	33.33	1	8.33	3	25.00	1	8.33
藏狐粪便	43	21	48.84	0	0	10	23.26	17	39.53
赤狐粪便	14	7	50.00	2	14.29	4	28.57	1	7.14
未识别宿主粪便	19	7	36.84	0	0	6	31.58	3	15.79
合计	138	42	30.43	3	2.17	25	18.12	23	16.67

动物	背部	腹部	肛周	头部	尾部	四肢	合计
犬	0/7	0/7	1/8	1/17	1/16	1/11	4/66
拴养犬	0/5	0/0	0/2	1/5	1/5	0/2	2/19
未拴养犬	0/2	0/7	1/6	0/12	0/11	1/9	2/47
牦牛	0/1	0/0	0/2	0/2	0/2	0/2	0/9
合计	0/8	0/7	1/10	1/19	1/18	1/13	4/75

样本来源	样本数（份）	检出数（份）	检出率（%）
水样本	13	2	15.38
野外河流溪水	10	2	20.00
村内井水	2	0	0
村内积水	1	0	0
土壤样本	114	6	5.26
养犬户家庭门口土壤	10	2	20.00
养犬户家庭院内土壤	10	1	10.00
村内主干道路土壤	8	0	0
村内支干道路土壤	12	3	25.00
野外土壤	74	0	0