ABSTRACT
Rickettsial microorganisms are strict intracellular bacteria under the alpha group of the class Proteobacteria. Rickettisases are vector-borne zoonotic infections caused by Rickettsia, which are divided into four groups. Flea-borne bacterial diseases like plaque, murine typhus, and flea-borne spotted fever are caused by R. felis. The advent of optical instrumentation practices paved the way to track new rickettsial bacterial species and to greater extend the polymerase chain reaction followed by gene sequencing comparison to define the classification of rickettsial typhus. The cosmopolitan condition of R. felis in its mammalian hosts has been reported in many countries. Serological diagnosis is complicated because of cross-reactivity of the human humoral immune response against other rickettsial types. Rickettsial incidence in India has been documented almost in all parts of the country, but specifically in northern and southern regions. Tick-borne rickettsiosis in Maharashtra reveals zoonotic occurrence of Indian tick typhus fever at an alarming rate. Serological tests under differential diagnosis are frequently used and widely available for diagnosis of rickettsial patients. Indeed, Weil-Felix tests are still under continual usage by many clinical laboratories throughout the world. Various antibiotics used for rickettsial diseases are tetracyclines, preferably doxycycline, chloromphinicol, macrolides especially azithromycin, clarithromycin, roxythromycin, telithromycin, rifampin, fluroquinolones, ciprofloxacin, ofloxacin, pefloxacin, and levofloxacin, which show promising effects in controlling the infection cycle. Though several antibiotics extend the feasibility of controlling rickettsial outbreaks, and relatively rickettsiostatic and nonrickettsiacidal activity, to date there no is vaccine available. However, definite treatment should be instituted based on clinical trials and epidemiological clues as early as possible to avoid adverse severity of the disease and fatal outcome. Pathogenicity awareness campaigns are the need of the hour in controlling emergence of human–flea-borne rickettsial diseases in the future.
