Detection of Rickettsia tamurae DNA in Ticks and Wild Boar (Sus scrofa leucomystax) Skins in Shimane Prefecture, Japan

We used 24 wild boars trapped from December 2009 to January 2010 and a further 65 from July 2010 to August 2010 in Misato Town, Shimane Prefecture, Japan. We collected blood, spleens, skins and ticks from the wild boars, which were examined for rickettsial infections using polymerase chain reaction (PCR) primers for the genes rickettsial 17-kDa antigen and citrate synthase (gltA). We amplified Rickettsia tamurae AT-1 DNA from the tick Amblyomma testudinarium and from wild boar skins where ticks attached. Antibodies against spotted fever group Rickettsia were detected in wild boar sera using immunofluorescence, whereas blood and spleen samples contained no rickettsial DNA. This study suggests that wild boars have a role as an amplifier and a transporter of A. testudinarium, which harbor R. tamurae. One case of R. tamurae infection in humans was reported in Shimane Prefecture. Therefore, R. tamurae infections in humans might increase, if wild boar populations and their habitats expand.