Rickettsial infections are caused by a variety of bacteria from the genera Rickettsia, Orientia, Ehrlichia, Neorickettsia, Neoehrlichia, and Anaplasma . Rickettsia spp. are classically divided into the typhus group and spotted fever group (SFG). Orientia spp. make up the scrub typhus group.All pathogenic Salmonella species, when present in the gut are engulfed by phagocytic cells, which then pass them through the mucosa and present them to the macrophages in the lamina propria. Nontyphoidal salmonellae are phagocytized throughout the distal ileum and colon.
In the Australia, about 650 cases of Typhus fever are reported in each year. Almost 12% of the Australia population is suffering with Typhus fever, a disease caused by bacteria called Rickettsia typhi or bacteria called Rickettsia felis.Treatment of patients with possible rickettsioses should be started early and should never await confirmatory testing, which may take weeks when serology is used. Immediate empiric treatment with a tetracycline is recommended, most commonly doxycycline. Broad-spectrum antibiotics are not usually helpful. Chloramphenicol may be an alternative in some cases, but its use is associated with more deaths.