Current Infectious Disease Reports

, Volume 11, Issue 1, pp 40–50

Tick-borne rickettsioses in America: Unanswered questions and emerging diseases

  • Philippe Parola
  • Marcelo B. Labruna
  • Didier Raoult

DOI: 10.1007/s11908-009-0007-5

Cite this article as:
Parola, P., Labruna, M.B. & Raoult, D. Curr Infect Dis Rep (2009) 11: 40. doi:10.1007/s11908-009-0007-5


During most of the 20th century, Rickettsia rickettsii, the agent of Rocky Mountain spotted fever, was considered the only tick-borne rickettsia associated with human diseases in the Americas. This dogma suggested that the other characterized and noncharacterized rickettsiae isolated from ticks were not pathogenic to humans. This concept has been modified extensively in the past 10 years with the identification of at least three additional rickettsial species that cause human tick-borne rickettsioses and that are prevalent in the Americas, including Rickettsia parkeri, Rickettsia massiliae, and Rickettsia africae. Moreover, the genetic variability of R. rickettsii and the milder forms of Rocky Mountain spotted fever reactivate the hypothesis that some circulating genotypes of R. rickettsii may be more virulent than others and may explain the wide variations in fatality rates of the disease.

Copyright information

© Current Medicine Group LLC 2009

Authors and Affiliations

  • Philippe Parola
  • Marcelo B. Labruna
  • Didier Raoult
    • 1
  1. 1.Unité de Recherche en Maladies Infectieuses et Tropicales Emergentes (URMITE), UMR CNRS-IRD 6236World Health Organization Collaborative Center for Rickettsial and Other Arthropod-Borne Bacterial Diseases, Faculté de MédecineMarseille Cedex 5France

Personalised recommendations