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
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!
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Outline
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Ticks & Lyme Disease
Tick Surveillance Program in Alberta
Results
Discussion & Next Steps
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Ticks & Lyme Disease
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Lyme Disease
• Borrelia burgdorferi
– Vector: Ixodes spp ticks
http://en.wikipedia.org/wiki/Borrelia
_burgdorferi
• Identified in 1976 in Lyme, Connecticut
– Cluster of juvenile arthritis cases
• Multi-system inflammatory disease
– Early symptoms: Rash, headache, fever, fatigue http://www.cdc.gov/tic
ks/symptoms.html
– Can affect heart, joints, brain
– Small number of patients can have pain, fatigue, or
other symptoms chronically after treatment
• Best if treated early
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Lyme Disease – Key Point
• Can be difficult to diagnosis as the symptoms
can be non-specific, especially if
characteristic rash absent
http://www.cdc.gov/ticks/symptoms.html
• Knowing that the individual has been in an
endemic area and exposed to ticks is
important for diagnosis
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Ixodes scapularis
• Black-Legged Tick
– Carrier of Borrelia burgdorferi
• Feeding
– Insert mouthparts
– Several days
• Drop off
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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
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Adventitious Tick: Going where
no Ixodes has gone before
• One method of spread: migratory birds
• Flyway over Edmonton
• Key: Suitable habitat to overwinter/reproduce
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birding.about.comodbirdingbasicsssNorth-America-Migration-Flyways.htm
Tick Surveillance Program
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Objectives:
1. Determine if Ixodes ticks can be found in
Alberta
2. Determine the percentage of Ixodes ticks that
carry Borrelia burgdorferi
3. Utilize geographic information to pick sites
for active surveillance
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Passive Surveillance
Companion
Animals
Veterinarian
Humans and the
Environment
AHS Environmental
Health Office
Agriculture and
Rural
Development Lab
Alberta
Health
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Methods
• Standardized lab methods
– 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
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Results
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Results
Total Ticks Submitted
B. burgdorferi
All Tick
Ixodes
positive
species
species
Ixodes spp
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
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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
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Results
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Submitter’s Postal Code of Residence
No travel in previous two weeks
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Discussion & Next Steps
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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
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Active Surveillance Triggered
Criteria
Reasonable Evidence
Strong Evidence
Same
 1 or more nymph or
larval blacklegged ticks
Submitter *
 >1 blacklegged tick of any
stage from the same
person or animal in a
suitable environment
Different
 >1 blacklegged tick of any  >2 blacklegged tick
stage from a different
submissions of any stage
Submitter*
submitter in a suitable
found at least 1 year apart
AND
environment
 The ticks were found in a
suitable environment
Human
 Single locally acquired
 Cluster of locally acquired
Cases
human case
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.
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Active Surveillance for Ticks
• Drag sampling 5 sites
weekly, May-June 2014
• If Ixodes found: Heightened
Active Surveillance
•
Likely include small mammal
trapping
http://www.youtube.com/watch?v=QfKhopJNuj0
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Strengths and Limitations
• Strengths:
– 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
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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
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Questions?
• www.health.alberta.ca/health-info/lyme-disease
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Ixodes spp – Life cycle
CDC
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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
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Last, John M. 2001. A Dictionary of Epidemiology,
4th
edition. Oxford University Press, Inc
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