For more information about this message, please visit this page: About CDC. Summary Tickborne rickettsial diseases continue to cause severe illness and death in otherwise healthy adults and children, despite the availability of low-cost, effective antibacterial therapy. Recognition early in the clinical course is critical because this is the period when antibacterial therapy is most effective. Early signs and symptoms of these illnesses are nonspecific or mimic other illnesses, which can make diagnosis challenging.
Vertebrate animals play an integral role in the life cycle of tick species, whereas humans are incidental hosts. Tickborne rickettsial diseases in humans often share similar clinical features yet are epidemiologically and etiologically distinct. Tickborne rickettsial diseases continue to cause severe illness and death in otherwise healthy adults and children, despite the availability of effective antibacterial therapy. Additional information concerning the tickborne rickettsial diseases described in this report is available from medical and veterinary specialists, various medical and veterinary societies, state and local health authorities, and CDC. The CDC Rickettsial Zoonoses Branch reviewed the 2006 report and determined which subject-matter areas required updates or revisions. Internal and external subject-matter experts in tickborne rickettsial diseases, representing a range of professional experiences and viewpoints, were identified by the CDC Rickettsial Zoonoses Branch to contribute to the revision.
Spotted Fever Group Rickettsiae SFG rickettsiae are related closely by various genetic and antigenic characteristics and include R. Rickettsia species 364D, as well as many other Rickettsia species of unknown pathogenicity. RMSF is the rickettsiosis in the United States that is associated with the highest rates of severe and fatal outcomes. Rickettsia rickettsii In the United States, the tick species that is most frequently associated with transmission of R.
These ticks also can be found in residential areas and city parks. Larval and nymphal stages of most Dermacentor spp. United States usually do not bite humans. Canids, especially domestic dogs, are the preferred hosts for the brown dog tick at all life stages.