Abstract
Spotted fever group rickettsioses are transmitted by several types of arthropods (including ticks, chiggers, fleas, and lice) and are distributed worldwide. Japanese spotted fever (JSF) was discovered as an emerging rickettsiosis in 1984. The annual number of cases has increased 3-fold during the last decade. In Japan, JSF has been mainly reported in an area with warm climate that borders the Pacific Ocean. We describe a family/neighborhood cluster of three cases of JSF in an area of Japan that had previously not been considered endemic.