The Lyme disease bacterium has considerable variation across Canada. Using DNA testing, researchers found wide genetic difference in Lyme disease bacteria contained in vector ticks that were removed from songbirds nationwide.
Three new Lyme strains were collected from two different tick species along coastal British Columbia. Of note, researchers report the first time account of a Lyme-carrying mouse tick collected from a songbird anywhere; the tick was collected from a white throated sparrow in northern Nova Scotia.
During the nationwide bird-tick study, Lyme disease bacteria were isolated from four different tick species. Researchers suggest common yellowthroat, golden crowned sparrow, song sparrow, and Swainson’s thrush are hosts that carry Lyme disease bacterium in their bodies, and transmit its parasite ticks.
The three year study revealed songbirds transport Lyme positive ticks northward into Canada during spring migration and carry them to northern Canadian latitudes from tick populations along the southern fringe of Canada.
Ticks were transported by songbirds as far north as the Yukon. One rare species was imported by a gray catbird during migratory flight from as far south as Central America.
Locally, a Lyme-infected tick was collected from a common yellowthroat in Toronto. The study concludes that people do not have to go to an endemic area to contract Lyme disease.
John Scott, of Fergus, is a researcher with Lyme Disease Association of Ontario. He recently presented the Fergus library with Ending Denial: The Lyme Disease Epidemic, A Canadian Public Health Disaster, by Helke Ferrie.
