New study shows 1 in 3 ticks tested in Ottawa carries Lyme disease

Some startling numbers out today indicate just how prevalent Lyme disease is now in the city of Ottawa.

New data shows that one in three ticks tested was positive for the bacteria that cause Lyme disease.

The study, which was done by University of Ottawa researchers shows that the tick population is far more widespread than previously thought. The worst areas in the city, both in the east and west, are along the Ottawa River and near the Greenbelt.

“We're still not experiencing tick infection rates like in the northeastern United States,” says Dr. Manisha Kulkarni, an epidemiologist with the University of Ottawa and lead researcher for the three-year study, “where 50% are infected and the tick numbers off the charts, compared to what we're seeing here.”

But Dr. Kulkarni says Canada and specifically Ottawa may be headed that way.

“With ongoing climate change issues and the northward movement of tick populations,” she says, “we're likely going to see increases in the number of ticks and those infection rates that we're seeing around the city of Ottawa.”

Researchers Dr. Manisha Kulkarni and Roman Kryuchkov, dressed in hazmat suits, dragged for ticks in 23 sites across Ottawa, including municipal parks, conservations areas, forests and recreational trails.  Black legged ticks were found in 16 of the 23 sites or about 70%.  Of the 194 adult and 26 nymphal blacklegged ticks tested, almost 30% were infected with the B. bulgdorferi, known to cause Lyme disease.

“The areas we're seeing the highest abundance (of infected ticks) are the western areas especially along the Ottawa River and the Greenbelt, due to the woodland habitat.”

Dr. Kulkarni says there are different control measures being examined to contain or reduce the number of ticks.

“We can use measures like barriers along trails to prevent ticks from coming into contact with humans or other control measures to target small mammals with to kill ticks before they encounter humans.”

The researchers are in the second year now of a three-year study measuring the tick population in Ottawa, along with infection rates.  Their most recent data was published today in the Canada Communicable Disease Report.