May 19, 2011
Lyme Disease Update
– – –Blacklegged Tick Population Established in South-central Manitoba
Manitoba Health advises that more blacklegged tick populations have been identified in Manitoba. Blacklegged ticks can carry the bacteria that causes Lyme disease.
In addition to the southeast corner of Manitoba, the area around the Stanley Trail in south-central Manitoba is now confirmed to have an established blacklegged tick population. Surveillance findings suggest the population may stretch from the trailhead at roads 27W and 2N in the south to Deerwood in the north and including Stanley Park.
Over one-third of the blacklegged ticks tested from this area carried the bacteria that causes Lyme disease. In the past, there have been two reported Lyme disease cases in humans with tick exposure near the Stanley Trail.
Surveillance also indicates that blacklegged ticks may have become established in the Pembina Valley. Ticks have been identified along the Pembina River Valley at the Pembina Valley Provincial Park near the U.S. border and at Road 22N (north of La Rivière). As well, blacklegged ticks may have become established in Beaudry Provincial Park just west of Headingley. More surveillance in these areas is planned for this summer and fall.
Blacklegged ticks were likely introduced to these areas by migratory birds which perch and rest in forested areas. These wooded areas also provide suitable habitat for blacklegged ticks. The agricultural lands surrounding these areas are unlikely to support many ticks.
Manitoba Health reminds Manitobans to take the following precautions to reduce the risk of coming into contact with blacklegged ticks while enjoying the outdoors:
- limit contact with tall grass or other vegetation along wooded areas and stay to the centre of hiking trails or paths;
- wear light-coloured clothing to make it easier to see ticks that may be on skin or clothing;
- wear long pants and a long-sleeved shirt in tall-grass habitats or wooded areas where ticks are most commonly found;
- tuck a shirt into pants and pants into socks to prevent ticks from attaching to the skin;
- apply an appropriate repellent (it should say “tick repellent” on the container) on clothing and exposed skin after reading and following instructions for use;
- inspect yourself, children and pets for ticks and remove them as soon as possible; and
- keep grass well mowed to help reduce the amount of habitat suitable for ticks.
Symptoms of Lyme disease can start about three days to one month after a tick bite, often with an expanding circular rash around the site of the bite which then fades. Early symptoms can also include headache, stiff neck, fever, muscle aches or fatigue, fever, chills and swollen lymph nodes. People who think they may have Lyme disease should see their doctor. Lyme disease can be successfully treated with antibiotics. Treatment is most successful in the early stages of infection.
At this time, no cases of Lyme disease have been reported in Manitoba in 2011. In 2010, Manitoba had six confirmed case of Lyme disease and six probable cases. Four additional reports not meeting the national surveillance case definition were also received. The definition for confirmed and probable cases for surveillance purposes is more stringent than clinical criteria used by physicians to consider treatment for Lyme disease.
Blacklegged ticks have been found throughout southern Manitoba and occasionally in the north. The ticks are thought to be deposited annually by birds. A low risk of exposure to blacklegged ticks is present in Manitoba. Approximately 300 blacklegged ticks were submitted in 2010 in the fall tick submission campaign.
Areas with established populations of blacklegged ticks have a greater risk of tick exposure. Established blacklegged tick populations are present in the southeast corner and in the Stanley Trail area of the province. Investigations into other areas of southern Manitoba are occurring.
More information on Lyme disease is available at the Manitoba Health website at www.gov.mb.ca/health/lyme or by contacting Health Links-Info Santé at 788-8200 (in Winnipeg) or at 1‑888-315-9257 (toll-free).
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