Primary investigation on the prevalence of Schistosoma japonicum and Exorchis sp. in Oncomelania hupensis (Gastropoda) field populations in marshlands of Poyang Lake, China, and observation on their cercarial release patterns in the laboratory
Abstract:Digenean trematodes are a widespread group of parasitic flatworms that use snails somewhat exclusively as their first intermediate host and one species can competitively exclude other species in a single individual snail. In this study, prevalence of the trematodes, Schistosoma japonicum and Exorchis sp., among populations of Oncomelania hupensis and population density of the snail in four different marshland locations around Poyang Lake, China, was studied during spring (April) and autumn (October) of 2012, by using a 0.11 m2 frame sampler. Also, the rhythm of cercarial liberation of the two trematodes from this area was investigated.
Results showed that the prevalence of Exorchis sp. infection among O. hupensis populations was higher (2.01%), compared to S. japonicum (0.15%) over the four investigated sites during the spring- and autumn-collected samples. The mean density of live snails in spring was 12.2 per 0.11 m2 with overall infection of 0.3 snails per 0.11 m2; while in autumn, the mean density of live snails was 6.7 per 0.11 m2 with infection rate of 0.2 snails per 0.11 m2. Cercarial release pattern from S. japonicum was circadian, with a single peak of emergence between 12:00 and 14:00 hr, whereas that of Exorchis sp. displayed a bimodal peak of emergence: an early emergence peak between 6:00 and 8:00 hr, and a late. emergence peak between 16:00 and 18:00 hr. Finaly, the higher prevalence of Exorchis sp. infection among O. hupensis populations compared to S. japonicum at different sites and seasons in this study necessitates further investigation concerning interaction among trematode infections within O. hupensis populations, especially in regard to Exorchis sp., due to its importance in schistosomiasis biological control.
收稿日期: 2013-03-08
出版日期: 2013-06-19
基金资助:国家自然科学基金
通讯作者:
Yassir A Sulieman
E-mail: noury39@gmail.com
引用本文:
Yassir A Sulieman Theerakamol Pengsakul. 鄱阳湖湖北钉螺日本血吸虫和外睾吸虫流行学初步调查及对它们尾蚴逸出模式的观察[J]. 中国人兽共患病学报, 2013, 29(4): 323-329.
Yassir ASulieman Theerakamol Pengsakul. Primary investigation on the prevalence of Schistosoma japonicum and Exorchis sp. in Oncomelania hupensis (Gastropoda) field populations in marshlands of Poyang Lake, China, and observation on their cercarial release patterns in the laboratory. Chinese Journal of Zoonoses, 2013, 29(4): 323-329.