Worldwide detection and identification of new and old rickettsiae and rickettsial diseases.

To determine the prevalence and distribution of rickettsial pathogens around the world, scientists have relied more and more upon molecular techniques in addition to serological and culture methods. The ease of use and sensitivity/specificity of molecular techniques such as quantitative real-time PCR assays and multilocus sequence typing have lead to an increase in reports of the detection and identification of new and old rickettsiae in previously known and in new endemic regions. These assays have been successfully used with clinical samples such as serum, blood, and tissue biopsies and with environmental samples such as arthropod vectors including ticks, fleas, lice, and mites, and blood and tissue specimens from small mammal collections and from wild and domestic large animals. These methods have lead to the detection of new and old rickettsial pathogens often in new locations leading investigators to suggest new regions of risk of these rickettsioses.