Scrub typhus in eastern Taiwan, 1970

An outbreak of scrub typhus occurred in Chinese Army personnel in the eastern part of Taiwan during 1970. This is the first outbreak of this disease documented on the main island of Taiwan since 1932. Of 21 hospitalized patients examined during the convalescent stage, 19 had antibody titers of from one to 640 to one to 10,240 as measured by indirect immunofluorescence to the Karp, Kato and Gilliam stains of Rickettsia tsutsugamushi. All were males of from 35 to 51 years and all had high fever by history. Eleven patients had eschars, six with typical black necrotic scabs. In addition, serologic evidence of prior scrub typhus infection was found in 59 of 241 other men from the two military companies involved in the outbreak. All men had been working clearing an area in hills 300 to 500 meters high. This land was originally cleared for agricultural use, but had been abandoned over 4 years previously. Rickettsia tsutsugamushi was recovered from rodents and chiggers (Leptotromibidium deliense) captured in the area.