Due to changes in lab protocols, as of October 1, 2017 we will only be accepting tick submissions from ticks found on humans. You can bring in any suspect black-legged ticks found on humans to the health unit to be assessed and/or tested for Lyme disease.
Public health's role is to measure and evaluate the risk of tick-borne disease in our area. The health unit conducts active and passive surveillance to determine where blacklegged ticks (deer ticks) are located in our area and if they can spread illness.
For active surveillance the health unit collects blacklegged ticks in the spring and fall by tick dragging according to the provincial protocol. In 2017, tick dragging was performed at 9 sites in the Kenora and surrounding area. Locations were chosen based on 2016 surveillance results, where the public tend to walk, and the presence of broadleaf vegetation. For passive surveillance, residents can bring ticks that are taken off of humans in to their health unit office or submit a picture electronically through our Healthy Environments app. Blacklegged ticks are sent to the lab to be tested for tick-borne diseases. If a tick cannot be identified by a public health inspector it will also be sent to the lab for further analysis.
Lab testing of ticks is not used to diagnose people, but to determine if infected deer ticks are becoming more common in our area, and if they are carrying tick-borne diseases.
Passive Tick Surveillance:
In 2017 354 ticks were submitted to the health unit, 72 (20.3%) of which were deer ticks which can carry tick-borne disease. Ten of these deer ticks tested positive for the bacteria that causes Lyme disease, which is about 14% of the submissions. Five of the positive ticks were in the Rainy River District, three were in Kenora, one was in Sioux Narrows and one was in Red Lake.
Active Tick Surveillance:
Six (6) of the 9 sites collected deer ticks; 3 sites had no deer ticks collected. A total of 102 blacklegged ticks were captured during active surveillance in 2017. The large majority of blacklegged ticks (75 ticks) were found at one tick dragging site.
Of the 102 blacklegged ticks, 61 tested positive for the bacteria that causes Lyme disease (59.8%). The percent positive at each site ranged from zero to 87.5%. The large majority of positive ticks (48 ticks) were found at one tick dragging site. As well, in the fall, of the 39 deer ticks, 8 tested positive for the bacteria that causes Anaplasmosis at three separate sites. No ticks collected in the spring were positive for Anaplasmosis.
Results from active surveillance by location for 2017 are outlined in the tables below.
Discussion and Limitations
Surveillance data should be interpreted as a guide. In 2017 active surveillance was focused around the Kenora area. Sampling locations were not chosen randomly. Other areas in the district may have blacklegged tick populations because of similar climate conditions and animal hosts, but were not actively surveilled.
Lyme Disease in Humans
There were 3 confirmed cases of Lyme disease in the NWHU area in 2017, which is relatively consistent with the average number of annual cases of 2.2 over the past five years. The highest number of cases in a year was 6 in 2016, but other than that year, the number of cases has ranged from 0 to 3 per year since 2005.
Travelling outside our regions?
Review neighbouring areas surveillance for Lyme disease.