High Seropositivity of Japanese Homosexual Men for Amebic Infection

About 340 Japanese homosexual men (average age 37 y) in two different communities, 120 women prostitutes, and 100 heterosexual men (average age 35 y) were recruited in Nagoya City, Aichi Prefecture, Japan. Serum specimens were taken and tested for antibody to amebae by the gel diffusion precipitation test (GDP) and ELISA. These data suggest that, in Japan, pathogenic Entamoeba histolytica causes symptomatic sexually transmitted amebiasis, in contrast to what has been observed in western countries. The possibility of pathogenic E. histolytica in communities of homosexual men should be considered.