shima-mushi, akamushi (red mite) or kedani (hairy mite) disease of northern Japan, and most popularly as tsutsugamushi (from tsutsuga meaning fever or harm or illness, and mushi meaning bug or insect). Japanese physician Hakuju Hashimoto gave the first medical account from Niigata Prefecture in 1810. He recorded the prevalence of infection along the banks of the upper tributaries of Shinano River. The first report to the Western world was made by Theobald Adrian Palm, a physician of the Edinburgh Medical Missionary Society at Niigata in 1878. Describing his first-hand experience, Palm wrote: The aetiology of the disease was unknown until the early 20th century. In 1908, a mite theory of the transmission of tsutsugamushi disease was postulated by Taichi Kitashima and Mikinosuke Miyajima. In 1915, a British zoologist, Stanley Hirst, suggested that the larvae of mite Microtrombidium akamushi (later renamed Leptotrombidium akamushi) which he found on the ears of field mice could carry and transmit the infection. In 1917, Mataro Nagayo and colleagues gave the first complete description of the developmental stages such as egg, nymph, larva, and adult of the mite. They also asserted that only the larvae bites mammals, and are thus the only carriers of the parasites. But then, the actual infectious agent was not known, and it was generally attributed to either a virus or a protozoan. The causative pathogen was first identified by Naosuke Hayashi in 1920. Confident that the organism was a protozoan, Hayashi concluded, stating, "I have reached the conclusion that the virus of the disease is the species of Piroplasma [protozoan] in question... I consider the organism in Tsutsugamushi disease as a hitherto undescribed species, and at the suggestion of Dr. Henry B. Ward designate it as Theileria tsutsugamushi." Discovering the similarities with the bacterium R. prowazekii, Mataro Nagayo and colleagues gave a new classification with the name Rickettsia orientalis in 1930. (R. prowazekii is a causative bacterium of epidemic typhus first discovered by American physicians Howard Taylor Ricketts and Russell M. Wilder in 1910, and described by a Brazilian physician Henrique da Rocha Lima in 1916.) The taxonomic confusion worsened. In 1931, Norio Ogata gave the name Rickettsia tsutsugamushi, while Rinya Kawamüra and Yoso Imagawa independently introduced the name Rickettsia akamushi. Kawamüra and Imagawa discovered that the bacteria are stored in the salivary glands of mites, and that mites feed on body (lymph) fluid, thereby establishing the fact that mites transmit