The odds of picking up a blacklegged deer tick – and contracting Lyme disease – are on the rise in Manitoba.
The southeast corner of Manitoba and an area around the Stanley Trail in south-central Manitoba now have established blacklegged tick populations. Surveillance findings suggest they now occupy an area that may stretch from the trailhead at roads 27W and 2N in the south to Deerwood in the north, including Stanley Park.
Ticks have also been identified in the Pembina Valley Provincial Park at Road 22N (north of La Riviere).
Studies show over one-third of the blacklegged ticks tested from the Stanley Trail area carried the bacteria that causes Lyme disease, a Manitoba Health news release stated. There have been two reported Lyme disease cases in humans with tick exposure near the Stanley Trail.
The tick population may have also become established at Beaudry Provincial Park, just west of Headingley.
Blacklegged ticks have been submitted from many locations in southern Manitoba and occasionally from more northern areas to officials running the Blacklegged Tick and Lyme Disease Surveillance Program. They receive anywhere from 150 to 300 blacklegged ticks per year.
Just because a tick carrying the bacteria is found in an area doesn’t mean there is an established or permanent population, as the tick may have just dropped off a migrating bird, said Terry Galloway, professor of entomology with the University of Manitoba’s faculty of agricultural and food sciences. Officials first conduct a field study to determine if ticks in all stages of development (larva, nymph and adult) are present.
“Once we have evidence of all of the stages in one location, we can confirm it’s established at that site,” said Galloway.
Being bitten by an infected tick is not cause for immediate alarm. A tick must be attached for 24 hours or more before the bacteria is transmitted. Officials are advising Manitobans to take extra precautions and to learn the difference between blacklegged deer ticks (which are smaller in size) and common dog ticks, also known as wood ticks, which do not transmit Lyme disease.
Symptoms often, but not always, begin three days to one month after a tick bite with an expanding rash which then fades. Early symptoms can also include headache, a stiff neck, fever, muscle aches or fatigue.
To date, no cases of Lyme disease have been reported in 2011. However in 2010, there were six confirmed cases and six probable cases. Four additional reports not meeting the national surveillance case definition were also received.
“Oncewehaveevidenceofallofthe stagesinonelocation,wecanconfirm it’sestablishedatthatsite.”
– terry galloway, professor of entomology at university of manitoba’s faculty of agricultural and food sciences
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 (tollfree).