Morton V, Meghnath K, Gheorghe M, Fitzgerald-Husek A, Hobbs J, Honish L, David S
Public Health Agency of Canada, Guelph, ON.
Public Health Agency of Canada, Ottawa, ON.
Can Commun Dis Rep. 2019 Sep 5;45(9):225-229. doi: 10.14745/ccdr.v45i09a01.
is an intestinal parasite that is not endemic in Canada. However, national outbreaks of locally acquired cases have been reported since 2013. These outbreaks were suspected to be associated with consumption of produce imported from countries where is endemic. Identification of the source can be challenging because of reporting delays and limited traceability of produce.
To report on a national outbreak of locally acquired cyclosporiasis, highlight the challenges of investigating these outbreaks and document the first time use of a control bank to recruit controls for a national outbreak case-control study in Canada.
Cases of cyclosporiasis were identified through provincial laboratory testing and reported through provinces to the national level. Cases were interviewed about food exposures using a questionnaire and food exposures reported by cases were compared to Foodbook reference values. To narrow down the food items of interest, a matched case-control study was conducted. Controls for the study were recruited primarily from a control bank, that is, a list of individuals who had previously agreed to participate in public health-related surveys.
In total, 87 cases of locally acquired cyclosporiasis with onset or report dates between May 19, 2016 and August 10, 2016 were reported by four provinces. Comparing case exposures to Foodbook reference values identified several food items of interest, including blackberries, other berries, herbs and leafy greens. The case-control study identified only blackberries and mesclun greens as significantly more frequently consumed by cases than controls. Due to lack of product details for blackberries and mesclun greens, the source of the outbreak was not conclusively identified.
Blackberries were the primary food item of interest, but could not be identified as the conclusive source due to lack of traceability. The control bank was found to be a useful tool for control recruitment.
是一种肠道寄生虫，在加拿大并非地方病。然而，自2013年以来已报告了多起本地感染病例的全国性疫情。这些疫情被怀疑与食用从该病流行国家进口的农产品有关。由于报告延迟和农产品可追溯性有限，确定源头可能具有挑战性。
报告一起全国性的本地获得性环孢子虫病疫情，强调调查这些疫情的挑战，并记录加拿大首次使用对照库为全国性疫情病例对照研究招募对照的情况。
通过省级实验室检测识别环孢子虫病病例，并通过各省上报至国家层面。使用问卷对病例进行食物暴露情况访谈，并将病例报告的食物暴露情况与Foodbook参考值进行比较。为了缩小感兴趣的食物范围，开展了一项匹配病例对照研究。该研究的对照主要从一个对照库中招募，即一份此前同意参与公共卫生相关调查的个人名单。
四个省份报告了总共87例2016年5月19日至2016年8月10日发病或报告的本地获得性环孢子虫病病例。将病例的暴露情况与Foodbook参考值进行比较，确定了几种感兴趣的食物，包括黑莓、其他浆果、草药和绿叶蔬菜。病例对照研究仅确定黑莓和混合生菜叶是病例比对照更频繁食用的食物。由于黑莓和混合生菜叶缺乏产品细节，疫情源头未能最终确定。
黑莓是主要感兴趣的食物，但由于缺乏可追溯性，不能确定为最终源头。对照库被发现是招募对照的有用工具。
