Article ID: JJID.2017.073
Data concerning the seasonality and geographical location of tsutsugamushi disease (TD) in Japan from 1955 till 2014 were compiled. After disappearance of the “classical” TD in mid-1960, there was a long near vacuum. Then, in 1975, TD epidemic with October-December seasonality emerged in southern prefectures, and in 1979 that with May-June seasonality in northern prefectures. The current TD epidemic could be classified according to seasonality and geography into three types; a large October-December epidemic with negligibly small May-June epidemic in southern part of Japan, a large May-June epidemic with middle-sized October-December epidemic on the Pacific Ocean Coast of northern Japan, and a large epidemic in May-June with negligibly small October-December epidemic on the Japan Sea Coast of northern Japan. In addition, there were few patients that scattered throughout the year in various places in Japan. How these different epidemic patterns emerged was discussed.
