Abstract：
Avian schistosomes inhabit the blood stream of domestic and wild birds with aquatic snails as their intermediate hosts. In the Neotropics there is an emerging effort to describe species from these hosts, including Chile, although the knowledge about their pathological consequences is mostly understudied. This study aimed to describe the pathological changes associated with the parasitism of a native schistosomatid restricted to the Southern Cone of Neotropics. To achieve this, a total of 401 Chilina dombeiana snails (Chilinidae) were collected in two locations from Southern Chile. All of them were disposed to cercarial release procedure for three consecutive days. Furcocercariae released were stained and characterized by microscopic evaluation. Then, all snails were dissected under stereomicroscope and preserved in 10 % buffered formalin until histopathological analysis was performed. Eight out 401 (P = 2 %) snails were found parasitized with avian schistosomes. The released furcocercariae were identified as Schistosomatidae gen. sp. Lineage II which was previously reported in the same host. The main pathological change was an atrophy of ovotestes and an absence or mild infiltration of hemocytes in the surrounding tissues. Besides, a co-infection with echinostomes was found which was associated with a moderate hemocyte infiltration, granuloma-like lesion, and a reduced presence of schistosome\' sporocysts. The latter would suggest an antagonistic interaction between these two digeneans, as has been proposed in the Echinostoma spp.-Schistosoma mansoni model. Despite the above, the release of furcocercariae was present but reduced, in contrast with the non-release of echinocercariae. This interaction requires further attention. This study represents the first attempt to characterize the pathological consequences of parasitism by a native, yet undescribed, avian schistosome in an endemic snail. Future studies should consider experimental infections to understand the dynamics of single infections in other Chilina species, including inter- and intra-specific parasitism as previous studies have found, including this study.
摘要：
禽类血吸虫以水生蜗牛为中间寄主，栖息在家禽和野生鸟类的血液中。在新热带，有一个新兴的努力来描述这些宿主的物种，包括智利,尽管关于其病理后果的知识大多是研究不足。这项研究旨在描述与仅限于新热带南部锥体的本地血吸虫寄生相关的病理变化。为了实现这一点，在智利南部的两个地方共收集了401只Chilinadombeiana蜗牛（Chilinidae）。所有患者均连续三天接受子囊释放手术。对释放的furcocer虫进行染色并通过显微镜评估进行表征。然后，所有蜗牛均在立体显微镜下解剖,并保存在10%缓冲福尔马林中,直至进行组织病理学分析.发现401只蜗牛中有8只（P=2％）被禽血吸虫寄生。被释放的furcocer被鉴定为血吸虫。sp.先前在同一宿主中报道的谱系II。主要病理变化是卵细胞萎缩，周围组织中没有或轻度浸润。此外,发现与棘突的共感染与中度血细胞浸润有关，肉芽肿样病变,血吸虫孢子的存在减少。后者暗示了这两个二系人之间的拮抗相互作用，正如棘皮动物中提出的那样。-曼氏血吸虫模型.尽管有上述规定,糠ceric的释放存在但减少，与不释放棘毛虫相反。这种互动需要进一步关注。这项研究代表了首次尝试描述本地人寄生的病理后果，但没有描述，一种特有蜗牛的禽类血吸虫。未来的研究应该考虑实验性感染，以了解其他Chilina物种中单一感染的动态，包括以前的研究发现的种间和种内寄生，包括这项研究。
