ABSTRACT
The typhus group of rickettsiae includes two diseases-epidemic typhus and murine typhus-which are produced by Rickettsia prowazekii and R. typhi, respectively. Both pathogens are small (0.3-2.0 µm), Gram-negative coccobacilli (Figure 17.1). Neither disease should be confused with typhoid fever, which is a disease caused by Salmonella bacteria.
