The vast majority of ticks found in Saskatchewan are Dermacentor variabilis (American dog tick), a species not known to be a competent vector of typical Lyme borreliosis (Borrelia burrgdorferi s.l.) to humans. However, recently Borrelia miyamotoi has been found in Canadian ticks coast to coast. Also, this from Manitoba, Saskatchewan’s next door neighbour. Borrelia miyamotoi causes similar disease in humans to Lyme borreliosis.
Needing more research is the potentially significant finding that the very common Dermacentor species of tick can be a vector of Borrelia miyamotoi … “Host seeking wood ticks, Dermacentor andersoni (Rocky Mountain Wood Tick), collected from zoonotic sites failed to induce productive infection in guinea pigs when homogenized and intraperitoneally injected, but those that were allowed to pre-feed for 24 hours on uninfected animals, then homogenized and injected into uninfected guinea pigs induced a typical fatal infection.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4662080/
What is also concerning about infection with B. miyamotoi is that it does not come with the identifiable rash but can have no rash or a small rash and, in most cases there will be no relapsing fever. Borrelia miyamotoi is unique in that it can be passed from mother tick to egg (transovarily) meaning the very tiny flesh coloured larvae about the size of a grain of sand can be infectious.
Ticks, human cases and blood samples tested in Saskatchewan (notice no reporting on Borrelia miyamotoi or another one, Borrelia mayonii. What is also remarkable about this below chart is that there is no mention of the several other known pathogens both the black-legged and dog ticks carry that are infectious to humans. NO TICK IS A GOOD TICK.
Source: Public Health Agency of Canada and the Roy Romanow Provincial Laboratory
|Year||Ticks (all species)||Black-legged ticks||Black-legged ticks