Tularemia in Deer Mice (Peromyscus Maniculatus) During a Population Irruption in Saskatchewan, Canada

Abstract

ABSTRACT:Type B tularemia caused by Francisella tularensis subsp. holarctica was diagnosed in deer mice (Peromyscus maniculatus) found dead at four sites in west-central Saskatchewan during April and May 2005. The occurrence of tularemia coincided with a decline in the number of deer mice in part of a large area (.22000 km 2 ) in which deer mice had been extremely abundant during the autumn of 2004 and spring of 2005, and in which mice caused damage to crops in the autumn of 2004. This is apparently the first report of tularemia as a cause of death of wild deer mice. The bacterium isolated from deer mice was atypical in that cysteine was not required in the media used for isolation. Three isolates tested were genotypes not previously identified in Canada. There were no reports of human disease in the area.

Rodent-borne diseases and their risks for public health

“…;Pape et al 2005;Petersen and Schriefer 2005;Wobeser et al 2007). Tularemia mainly occurs in the northern hemisphere and most frequently in Scandinavia, Central Europe, Northern America, Japan, and Russia, although F. tularensis subsp.…”

Experimental Infection of Voles with Francisella tularensis Indicates Their Amplification Role in Tularemia Outbreaks

“…F. tularensis is renowned for its high infectivity and wide host range. The infectious dose for humans can be as low as 10 bacteria [9] , and the bacterium has been isolated from numerous mammalian species, including rabbits, hares, voles and other rodents [10] – [13] , and detected from natural waters and mud, and from mosquito larvae collected in endemic areas [14] , [15] . It is very likely that F. tularensis persists in natural waters, possibly in aquatic protozoa [16] .…”

Association of Different Genetic Types of Francisella-Like Organisms with the Rocky Mountain Wood Tick (Dermacentor andersoni) and the American Dog Tick (Dermacentor variabilis) in Localities Near Their Northern Distributional Limits

“…The causative agent was identified as F. tularensis subsp. holarctica, but the source of infection was not determined (63).…”