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Results of a Passive Tick Surveillance System in Alberta

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1 Results of a Passive Tick Surveillance System in Alberta
Allison N Scott, Daniel Fitzgerald, Lisa Lachance, Kimberley Simmonds, and the Arthropod-Borne Diseases Committee (AABDC) Government of Alberta 2014 Canadian Public Health Association Conference Toronto, Ontario May 29, 2014

2 Collaborators Agriculture and Rural Development, GOA
Rashed Cassis Daniel Fitzgerald Alberta Health, GOA Dean Blue Patti Kowalski Lisa Lachance Martin Lavoie Kimberley Simmonds Theresa St. Jean The Arthropod-Borne Diseases Committee Alberta Health Services Lance Honish First Nations and Inuit Health Branch And Many More!

3 Outline Ticks & Lyme Disease Tick Surveillance Program in Alberta
Results Discussion & Next Steps

4 Ticks & Lyme Disease

5 Lyme Disease Borrelia burgdorferi
Vector: Ixodes spp ticks Identified in 1976 in Lyme, Connecticut Cluster of juvenile arthritis cases Multi-system inflammatory disease Early symptoms: Rash, headache, fever, fatigue Can affect heart, joints, brain Small number of patients can have pain, fatigue, or other symptoms chronically after treatment Best if treated early

6 Lyme Disease – Key Point
Can be difficult to diagnosis as the symptoms can be non-specific, especially if characteristic rash absent Knowing that the individual has been in an endemic area and exposed to ticks is important for diagnosis

7 Ixodes scapularis Black-Legged Tick Feeding Drop off
Carrier of Borrelia burgdorferi Feeding Insert mouthparts Several days Drop off

8 Ixodes spp Ticks Endemic in the United States
Establishing themselves in Eastern Canada Climate change: warm, mixed forest/grassland Ogden 2014 CCDR Volume 40-5

9 Adventitious Tick: Going where no Ixodes has gone before
One method of spread: migratory birds Flyway over Edmonton Key: Suitable habitat to overwinter/reproduce birding.about.comodbirdingbasicsssNorth-America-Migration-Flyways.htm

10 Tick Surveillance Program

11 Objectives: Determine if Ixodes ticks can be found in Alberta
Determine the percentage of Ixodes ticks that carry Borrelia burgdorferi Utilize geographic information to pick sites for active surveillance

12 Passive Surveillance Humans and the Environment Companion Animals
AHS Environmental Health Office Veterinarian Agriculture and Rural Development Lab Alberta Health

13 Methods Standardized lab methods Descriptive statistics (SAS)
Dichotomous identification key to speciate ticks Established PCR protocol utilized to identify Borrelia burgdorferi Descriptive statistics (SAS) Mapped postal code of residence (ARC GIS) Restricted to hosts that were Alberta residents and had not travelled in the previous 2 weeks. Finding nymph or larva would suggest a population capable of reproducing

14 Results

15 B. burgdorferi positive
Results All Tick species Ixodes species B. burgdorferi positive Ixodes spp Total Ticks Submitted 960 171 (18%) 27 (16%) Ticks Submitted by Alberta Residents With No Travel Outside of Alberta 580 139 (24%) 25 (18%) Tick Submitted by Alberta Residents With No Travel 378 105 (28%) 21 (20%) Only adult Ixodes ticks found from individuals who had not travelled

16 Results 54% of Ixodes ticks submitted by Alberta residents with no travel history reside in Edmonton Zone Submitter’s Postal Code of Residence No travel in previous two weeks

17 Results Submitter’s Postal Code of Residence
No travel in previous two weeks

18 Discussion & Next Steps

19 Discussion Ixodes ticks found in Alberta Mostly in Edmonton Zone
20% of Ixodes positive for Borrelia burgdorferi Only adults found But more than one tick likely acquired in certain areas

20 Active Surveillance Triggered
Criteria Reasonable Evidence Strong Evidence Same Submitter * 1 or more nymph or larval blacklegged ticks >1 blacklegged tick of any stage from the same person or animal in a suitable environment Different Submitter* >1 blacklegged tick of any stage from a different submitter in a suitable environment >2 blacklegged tick submissions of any stage found at least 1 year apart AND The ticks were found in a suitable environment Human Cases Single locally acquired human case Cluster of locally acquired human cases * In the same location. The location is in the same town, city or geographic area not defined by a specific surface area size.

21 Active Surveillance for Ticks
Drag sampling 5 sites weekly, May-June 2014 If Ixodes found: Heightened Active Surveillance Likely include small mammal trapping

22 Strengths and Limitations
Strong partnership between Alberta Agriculture, Alberta Health Services, and Alberta Health Collaborating with municipalities Limitations: Residential postal codes, not locations Unable to interview companion animal owners Postal codes for companion animals currently only available for 2013 Small sample size

23 Next Steps Active surveillance Changes to forms
Enhanced information on outdoor locations pets/people had been in previous two weeks Continued passive surveillance Increase sample sizes Enhanced advertising for 2014 season

24 Questions?

25 Ixodes spp – Life cycle CDC

26 Tick Surveillance Surveillance:
“Systematic ongoing collection, collation, and analysis of data and the timely dissemination of information to those who need to know so that action can be taken.” Passive Surveillance and Active Surveillance Last, John M A Dictionary of Epidemiology, 4th edition. Oxford University Press, Inc



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