“…Large outbreaks of shigellosis in the United States usually are confined to institutions for the mentally retarded, psychiatric hospitals, ghettos, and Indian reservations, where sanitary facilities or good personal hygiene are minimal or lacking (2)(3)(4)(5). In Sitka the original source of the outbreak could not be identified, but the following epidemiologic data support the supposition that person-to-person transmission was the subsequent mode of spread.…”