Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada.
School of Public Health, University of Alberta, Edmonton, AB, Canada.
Zoonoses Public Health. 2020 Jun;67(4):352-361. doi: 10.1111/zph.12693. Epub 2020 Feb 17.
High prevalences of Cryptosporidium and Giardia were recently found in enteric illness patients in the Qikiqtaaluk region of Nunavut, Canada, with a foodborne, waterborne or animal source of parasites suspected. Clams (Mya truncata) are a commonly consumed, culturally important and nutritious country food in Iqaluit; however, shellfish may concentrate protozoan pathogens from contaminated waters. The goal of this work was to investigate clams as a potential source of Cryptosporidium and Giardia infections in residents in Iqaluit, Nunavut. The objectives were to estimate the prevalence and genetically characterize Cryptosporidium and Giardia in locally harvested clams. Clams (n = 404) were collected from Iqaluit harvesters in September 2016. Haemolymph (n = 328) and digestive gland (n = 390) samples were screened for Cryptosporidium and Giardia via PCR, and amplified products were further processed for sequence analyses for definitive confirmation. Giardia DNA was found in haemolymph from 2 clams, while Cryptosporidium was not detected. The two Giardia sequences were identified as zoonotic Giardia enterica assemblage B. The overall prevalence of Giardia in clams near Iqaluit was low (0.6%) compared with other studies in southern Canada and elsewhere. The presence of Giardia DNA in clams suggests human or animal faecal contamination of coastal habitat around Iqaluit in shellfish harvesting waters. Results from this study are intended to inform public health practice and planning in Inuit Nunangat.
在加拿大努纳武特地区的伊魁特，最近发现肠道疾病患者中存在高比例的隐孢子虫和贾第鞭毛虫，怀疑寄生虫的来源是食源性、水源性或动物源性。贻贝（Mya truncata）是伊魁特地区一种常见的、具有文化意义的、营养丰富的本土食物；然而，贝类可能会浓缩来自受污染水域的原生动物病原体。这项工作的目的是研究贻贝是否可能成为努纳武特地区伊魁特居民感染隐孢子虫和贾第鞭毛虫的来源。具体目标是评估当地贻贝中隐孢子虫和贾第鞭毛虫的感染率，并对其进行基因特征分析。2016 年 9 月，从伊魁特的渔民那里采集了 404 只贻贝。通过 PCR 对 328 份血淋巴和 390 份消化腺样本进行了隐孢子虫和贾第鞭毛虫的筛查，扩增产物进一步进行了序列分析以进行明确确认。在 2 只贻贝的血淋巴中发现了贾第鞭毛虫 DNA，而未检测到隐孢子虫。这两个贾第鞭毛虫序列被鉴定为动物源的贾第虫 enterica 组合 B。与加拿大南部和其他地区的其他研究相比，伊魁特附近贻贝中贾第鞭毛虫的总体感染率较低（0.6%）。贻贝中存在贾第鞭毛虫 DNA 表明，在伊魁特沿海贝类捕捞水域，人类或动物粪便污染了沿海栖息地。本研究的结果旨在为因纽特努纳武特地区的公共卫生实践和规划提供信息。
