May 30th 2012
The following background information is abstracted from Gideon www.GideonOnline.com and the Gideon e-book series. [1,2]
Time and Place:
The first case of Lyme disease in Canada was reported from Quebec in 1984.
– Approximately 100 cases had been reported as of 1990 (67 of these from Ontario); 205 as of 1994 (105 of these autochthonous).
– As of 1997, cases were reported from New Brunswick, Quebec, Ontario, southern Manitoba and British Columbia.
– 280 cases were reported from Ontario during 1981 to 1998 (127 locally acquired); 172 during 1999 to 2004 (31 locally-acquired).
– 20 cases were reported in Alberta during 1989 to 2008.
– Nova Scotia reported its first locally-acquired case of Lyme disease in 2002.
– 93 cases were confirmed in British Columbia during 1997 to 2008 (true number estimated at 142).
Vectors and Reservoirs:
– The local vectors include the deer tick (Ixodes scapularis), western blacklegged tick (I. pacificus) and rabbit tick (Haemaphysalis leporispalustris – possibly an enzootic vector in Alberta).
– As of 2000, I. scapularis had been found in over 250 locations in Canada including Ontario, Newfoundland, Nova Scotia , New Brunswick, Quebec, Manitoba, Prince Edward Island and Saskatchewan; the Long Point Peninsula on Lake Erie (southern Ontario); Point Pelee National park and Rondeau Provincial Park on the north shore of Lake Erie; and Atlantic Canada.
– I. pacificus is found in the southern and coastal regions of British Columbia (Borrelia burgdorferi has also been found in Ixodes angustus in these areas), the Gulf Islands and Vancouver Island.
– Passerine birds appear to disperse infected ticks in Canada.
– An infected tick (Ixodes scapularis) was found on a bird (common yellowthroat = Geothlypis trichas) in Nova Scotia (1999).
– Borrelia burgdorferi has been identified in an additional avian tick species, Ixodes auritulus.
– Borrelia garinii has been identified in seabird ticks (Ixodes uriae) in Newfoundland. Ixodes uriae is a known parasite of deer mice (Peromyscus maniculatus) on the Gannet Island Archipelago, Newfoundland and Labrador.
12.5% I. scapularis, including 10.1% of ticks collected from humans (2006 publication)
8% of I. scapularis nymphs recovered from northward migrating birds in non-endemic areas of Eastern Canada (2005 to 2006)
11.4% of ticks collected from songbirds (2004 to 2006)
67% of tick pools collected at Turkey Point Provincial Park, Ontario (2005 to 2006)
29.5% of ticks infesting songbirds, nationwide (2011 publication)
1. Berger SA. Infectious Diseases of Canada, 2012. 496 pages, 107 graphs, 3130 references. Gideon e-books, http://www.gideononline.com/ebooks/country/infectious-diseases-of-canada/
2. Berger SA. Lyme Disease: Global Status, 2012. 73 pages, 65 graphs, 593 references. Gideon e-books, http://www.gideononline.com/ebooks/disease/lyme-disease-global-status/