The Discovery and Pursuit of American Boutonneuse Fever: A New Spotted Fever Group Rickettsiosis'

There is a new tick-borne disease similar to Rocky Mountain spotted fever (RMSF) that was recently described from the southern United States. Cases of the disease are a subset of reported RMSF cases and therefore constitute a “disease within a disease.” The causative agent of this RMSF-like disease, however, is Rickettsia parkeri as opposed to R. rickettsii, the pathogen causing RMSF. Both organisms are in the spotted fever group (SFG) of rickettsiae, cross-react in laboratory tests used to diagnose RMSF, and therefore are difficult to differentiate serologically. The new malady has been tentatively named “American Boutonneuse Fever” (ABF) based on clinical similarities with Boutonneuse Fever, a spotted fever-like disease also known as Mediterranean spotted fever, which occurs in the Eastern Hemisphere. This paper highlights several research projects currently underway at Mississippi State University to investigate the prevalence, epidemiology, and natural history of ABF, as well the ecology of its tick vector.