Lyme Disease: Environmental Surveillance Board of Health April 19, 2017

Transcription

1 Lyme Disease: Environmental Surveillance Board of Health April 19, 2017 Steve Rebellato Director (Environmental Health Department) Marina Whelan Manager (Health Hazards & Vector-borne Disease)

2 What is Lyme Disease clusterof children and adults in the Lyme, Connecticut area with uncommon arthritic symptoms Borrelia burgdorferi First identified in Ontario in 1993 Blacklegged tick (Ixodes scapularis) Reportable disease since 1988 HPPA An emerging disease migrating northward over time, with climate change

3 Clinical Signs and Symptoms of Lyme Disease

4 Signs and Symptoms Source: CDC, 2016 (

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6 Lyme disease in Simcoe Muskoka Potential Exposure Locations for Lyme Disease* Cases Among Simcoe Muskoka Residents, (N=36) Data Source: Integrated Public Health Information System (iphis), extracted August 2016 *Confirmed Cases Notes: 1. Each Case may have more than one potential exposure location. 2. Potential exposure location is a site identified by a case where they have spent time outside and/or may have acquired a tick bite during the incubation period. 3. This excludes data from cases who reside outside of Simcoe Muskoka 4. Simcoe County and District of Muskoka are not included in non-endemic Ontario or endemic Ontario categories.

7 Life Cycle Year 1 Larvae. Eggs Nymphs Life Cycle Credit: Ontario Agency for Health Protection and Promotion (Public Health Ontario). Blacklegged tick life cycle. Toronto, ON: Queen s Printer for Ontario; Adults Year 2

8 This document was adapted with the permission of Public Health Ontario. Public Health Ontario assumes no responsibility for the content of any publication resulting from translation/ changes/ adaptation of PHO documents by third parties.

9 Expansion of blacklegged ticks: Impact of climate change Source: Ogden et al, 2008a Survival of BLTs dependent on habitat and climate (Ogden et al. 2008) Potential BLT expansion has been captured in vector surveillance studies (Berry et al. 2014) New tick habitats may also be impacted by alterations in land use (e.g. farm land to forest, movement of residential encroachment)

10 Passive Surveillance: What have we found? Examples of species commonly identified through SMDHU submissions in 2016: Tick Submissions in Simcoe Muskoka, (n=502) Type of Ticks Submitted Blacklegged Tick Acquisition Location Locally acquired I. scapularis 62% 70% 30% Travel acquired (I. scapularis) American Dog Tick (D. variabilis) Blacklegged Tick (I. scapularis) Groundhog Tick (I. cookei) 23% 15% Unknown acquisition (I. scapularis) 33% 28% 18% Ixodes scapularis (blacklegged) tick Other tick species DataSource: Passive Tick Surveillance Data, extracted February 17, 2017.

11 160 Tick Submissions to Simcoe Muskoka District Health Unit* and Locally Acquired Ticks Positive for Lyme Disease, Number of Ticks Submitted Year All tick species Ixodes scapularis (blackleged) ticks Locally acquired ticks positive for Borrelia burgdorferi Data Sources: Passive Tick Surveillance Spreadsheet, extracted February 17, *Ticks are submitted to the health unit by those who have removed it from their (or another person's) body, and are aware to submit it to the health unit for testing. Submitted ticks may originate from anywhere that the submitter has traveled in recent days, and not necessarily from within Simcoe Muskoka. 62% of submitted ticks are acquired in Simcoe Muskoka.

12 PHO Recommendations: BLT Surveillance Blacklegged tick surveillance categories for PHUs Tick surveillance decision tree Figures adapted from: Ontario blacklegged tick surveillance: Quick guide for Public Health Units (2016); Technical Report: Update on Lyme disease prevention and control. Second edition (2016)

13 Blacklegged Ticks in Simcoe Muskoka: Passive tick surveillance has shown us that blacklegged ticks arepresent in Simcoe Muskoka Data Sources: Public Health Ontario Public Health Agency of Canada: National Microbiology Laboratory SMDHU Simcoe Muskoka NOS Adjala Tosorontio Angus Barrie Bradford West Gwillimbury Christian Island Clearview Collingwood Essa Innisfil Midland New Tecumseth Orillia Oro-Medonte Penetanguishene Ramara Severn Simcoe NOS Springwater Tay Tiny Wasaga Beach Bracebridge Georgian Bay Gravenhurst Huntsville Lake of Bays Muskoka Lakes Muskoka NOS SMDHU Ixodes Sampled PHO Ixodes Total NML Ixodes Sampled

14 Active Surveillance Tick Dragging Assists in the determination of provincial risk areas Risk Area : where at least oneblt is collected during spring AND fall sampling events (late April/May and October) Site selection based on analysis of passive data and positive indicators (BLTs -positive & negative, human cases) + habitat Beneficial to conduct sampling over a two year period to determine if a tick population has been established (i.e. all life stages present) Tracks the expansion of BLTs and the prevalence of B.Burgdorferiprovincially and locally

15 Public Health Awareness & Education Public Health s Role Interpret surveillance data Passive (tick submission) data Active (tick dragging) data Human (confirmed and probable) Conduct local risk assessments Communicate potential risks Collaborate with key stakeholders Provide information on risk, personal protection, awareness of Lyme disease Environmental and human case surveillance activities: support better diagnosis and clinical assessment of Lyme disease; assess Simcoe Muskoka as a potential risk area; increase local awareness of tick populations and Lyme disease risk; Educate residents and visitors on personal protection and exposure reduction

16 Thank You QUESTIONS..