Tsutsugamushi Disease (Scrub Typhus) in World War II

Abstract

This report, the 12th Theobald Smith lecture before the New York Society of Tropical Medicine, reviews advances made in our knowledge of this disease incidental to military activities in World War II of the British, Australian, American, and Japanese forces in the Asiatic Pacific Region. Available data on incidence and fatality in these various troops are discussed and tabulated. Five named investigators who died are memorialized, and other laboratory infections are mentioned. Distributional data were augmented intensively and extensively as figured. Natural infection was confirmed in the classic mite vector, Trombicula akamushi, and demonstrated for the first time in T. deliensis as well as transovarial and transtadial transmission of the disease agent in the latter. Much added evidence of the close taxonomic relationship of these 2 was adduced in mite surveys in various areas. Incidental to epidem-iological studies, many new species of mites, and a few new vertebrate hosts were discovered. Five spp. of rats, one field mouse, and one insectivore were added to the list of naturally infected hosts. Laboratory techniques were refined, including successful complement fixation, and demonstration of wide antigenic differences in different strains of Rickettsia tsutsugamushi which complicated preparation of protective vaccines. New, durable chemical agents were found which provided protection either as clothing impregnants or as ground disinfectants.