The genus Rickettsia includes many species of bacteria associated with important and severe human or canine disease, including those in the spotted fever group and in the typhus group. The typhus group (TG) is composed of R. prowazekii and R. typhi, which are associated with lice and fleas, respectively; the spotted fever group (SFG), which includes more than 20 valid species, is mostly associated with ticks. Other species, such as R. bellii and R. canadensis, both associated with ticks, have been considered a distinct group sharing antigenic, genetic and ecological characters of both TG and SFG rickettsiae (Parola et al., 2005; Roux et al., 1997; Stothard et al., 1994).

Two important species are listed in more detail: Rocky Mountain spotted fever (RMSF), as a potentially fatal rickettsial disease of dogs and humans caused by R. rickettsii, and R. parkeri Infection as an emerging human pathogen, for which the dog has an important sentinel function.

For more information about these two pathogens see the following chapters:

• Rocky Mountain spotted fever
• Rickettsia parkeri Infection

Further information

• Pfeffer, M.: Rickettsia – a group of neglected pathogens. Proceedings of the 3rd Int. CVBD Symposium, 2008, 72-77 (Download)