Public health officials in Toronto and the surrounding regions are warning residents that blacklegged ticks that have recently tested positive for Lyme disease have been found in the Rouge Valley.

In a statement released Wednesday, Toronto Public Health said a search for ticks in the urban park was recently conducted after receiving reports that they were found by people who had been in the area.

A sample of ticks was collected by public health officials from Toronto, York and Durham, and they were sent for testing. Some of the ticks tested positive for Lyme disease.

"This new information suggests blacklegged ticks and Lyme disease are becoming established in the Rouge Valley," the statement said.

Blacklegged ticks are small, ranging in size from a poppy seed to a pea. They are the only type in Ontario that carries Lyme disease.

Symptoms for Lyme disease can differ from person to person. Early symptoms usually occur within one to two weeks of a bite, but can also appear as soon as three days or as long as a month after being infected.

Symptoms include:

  • Fever
  • Headache
  • Muscle and joint pains
  • Fatigue
  • An expanding "bull’s-eye" shaped rash at the site of the tick bite

While the likelihood of becoming infected is higher during the spring and summer months, public health officials are warning residents to take precautions in brushy or wooded areas of the Rouge Valley. It is suggested that people:

  • Wear long-sleeved shirts and pants
  • Wear socks and closed footwear
  • Tuck their pants into their socks
  • Wear light-coloured clothing, which makes it easier to spot tiny ticks
  • Use insect repellent that contains DEET
  • Check their pets for ticks, and put a tick and flea collar on them

If left untreated, Lyme disease can result in recurring arthritis, numbness and or paralysis. These symptoms can last months to years. The Public Health Agency of Canada says while fatalities from Lyme disease are not common, they have been reported.

Toronto Public Health says it is working with York and Durham to continue monitoring the blacklegged tick population in the Rouge Valley. They say "active monitoring" will resume in 2015 when temperatures rise and the risk of Lyme disease increases.

To learn more about Lyme disease, visit the Public Health Agency of Canada.