Evaluation of the public health impact of Ixodes scapularis in Canada: A synthesis research approach




Poster session 2 Thursday: Evidence synthesis - methods / improving conduct and reporting


Thursday 14 September 2017 - 12:30 to 14:00


All authors in correct order:

Waddell L1, Greig J1, Mascarenhas M1, Harding S1, Young I2
1 public health agency of canada, Canada
2 Ryerson University, Canada
Presenting author and contact person

Presenting author:

Lisa Waddell

Contact person:

Abstract text
Background: Ixodes scapularis (the black-legged tick) carries and transmits several pathogens to humans including Borrelia burgdorferi (Lyme disease), Powassan virus and Babesia sp. With climate change these tick vectors are expanding their geographical range northward. It is predicted that an increasing proportion of Canadians will be living in tick endemic areas.

Objectives:Conduct scoping reviews (ScR) of the literature on several vector-borne diseases transmitted by I. scapularis and other ticks in Canada. Prioritise systematic reviews (SR) and develop evidence-informed summaries in support of public health decision making, research and prevention activities.

Methods: ScRs identified and classified the literature on B. burgdorferi, Powassan virus and Babesia sp. Several SRs were prioritised to examine the evidence on risk factors, mitigation strategies, and the burden of disease in Canada and the United States. The ScR and SR methods have been adapted to accommodate diverse evidence and study designs.

Results: The ScRs include 2294 publications for Lyme disease (literature up to Sept 2016), 164 publications for Powassan virus (Nov 2016) and XXX for Babesiosis (Feb 2017) will be presented at the Summit. These include research on the pathogens, humans, vectors and non-human hosts. Key knowledge gaps were vector range and density of pathogens in ticks and the importance of potential reservoirs (e.g. birds infected with B. burgdorferi). This is important for understanding transmission dynamics, spread of the pathogens, and risk of exposure in humans.

Conclusions: The ScR information can be used to answer urgent requests for information; funding research to address knowledge gaps; and to prioritise SRs. SR outputs include evidence-informed summaries and inputs for quantitative inputs for quantitative-risk assessments. The transparency and accountability of synthesis research methodologies combined with a framework for timely response to urgent information requests to address long-term priorities through ScRs and SRs, has laid the foundation for how synthesis research can be used for decision making on vector-borne disease issues.