Distribution of Blacklegged Ticks Collected in Manitoba 1995 - 2011

Passive surveillance  to detect Ixodes scapularis (blacklegged ticks) has been occurring in Manitoba since 1995. The ticks (also known as deer ticks) are voluntarily submitted by veterinarians, physicians and the general public. Active surveillance activities are undertaken when evidence, including tick submissions, indicates that further investigation is needed.

An established population is an area known to have blacklegged ticks in all stages of their life cycle present on a permanent basis. Active surveillance is performed to determine if a tick population is established. The map shows established tick populations (south east corner of the province, the Stanley Trail/Thompson Trail and the area around Pembina Valley Provincial Park), suspected established tick populations (Pembina Valley, Beaudry Park, St. Malo area and Arbakka) and areas where ticks have been submitted by the passive surveillance program.

Areas with known established tick populations present a higher risk that people may come into contact with an infected tick.  Ticks found sporadically throughout Manitoba are often dropped from migrating birds and do not necessarily mean an established population will develop in that area. These submissions illustrate that there is a low risk of coming into contact with an infected tick throughout much of southern Manitoba.  Precautions should be taken whenever spending time in suitable tick habitat such as tall grasses and wooded areas from early spring through late fall, particularly doing a ‘tick check’ when returning home (more on prevention: http://www.gov.mb.ca/health/lyme/about.html#3).

The map shows the dispersal of blacklegged ticks submitted by Manitobans between 1995 and 2010*. However, marks on the map do not represent the number of ticks submitted from a particular location.  Ticks may have been submitted individually, multiple ticks may have been submitted at one time from one location or multiple ticks may have been submitted at different times from the same location. Ticks may have been found on humans, pets, or other animals. Since the ticks are submitted by people, the marks on the map are more likely to reflect areas where people live or visit. Blacklegged ticks may be present in other areas of province as well. 

Blacklegged ticks are capable of carrying and transmitting Borrelia burgdorferi, the bacteria that causes Lyme disease.

Since 2008, between 150 and 300 blacklegged ticks have been submitted per year through the passive surveillance program and 10-15 per cent of these test positive for the bacteria. This map represents ticks submitted and does not indicate which ticks were infected with Lyme disease bacteria.

* The map has not been updated with the passive tick surveillance data for 2011 but includes the results of the 2011 active surveillance activities.