[The first two cases of tsutsugamushi disease found in Toshima Island, Tokyo Metropolis]

It has been known that tsutsugamushi disease, so-called "Shichito-fever", is widely spread among the Izu Islands, Tokyo Metropolis. The cases were reported in Oshima Island, Niijima Island, Shikine Island, Kozu Island, Miyake Island, Mikura Island, and Hachijo Island previously, although no case has been reported in Toshima Island. In this paper, we report the first two cases of tsutsugamushi disease found in Toshima Island in December 1988 and December 1989. The first case was a 73 year-old male and the second case was a 83 year-old female, respectively. Fever, erythema and eschar were observed in both cases, while lymphadenopathy and hepatosplenomegaly were not detected. After tetracycline was administered, the fever immediately went down and erythema gradually disappeared in both cases. Specific immunofluorescence tests demonstrated that IgG antibody titers rose against Karp, Gilliam and Kato strains, and that IgM antibody titers rose only against Gilliam strain in both cases. Therefore, Gilliam-like strain of Rickettsia tsutsugamushi may play an important role in Toshima Island.