Only, if it became possible the knowledge of its distribution in the domestic territory when, almost half century later, Pellon & Teixeira (1950) had carried through first the great coproscpico inquiry of the country, having evidenced the existence of esquistossomose mansnica in 612 of the 877 localities searched in the Northeast region and the State of Minas Gerais. Esquistossomose mansnica in the State of the Bahia presents heterogeneous standard of space distribution, evidencing especificidades in its dynamics of transmission in the diverse spaces that constitute the bahian territory. This heterogeneidade is not exclusive attribute of the current period, but the northeast region has been expressed in previous stages of the historical process of construction of the bahian space is one of the endemic regions of Brazil. The basic conditions for the introduction of esquistossomose in the Northeast region occurred of the use of the hand of enslaved workmanship in the canavieira farming where the culture if developed in areas with great arrives in port hdrico, and associate to the precarious conditions of life and the probable existence of the caramujos of the transmissoras species of the S. mansoni (Barreto, 1982) In the inquiry carried through for Pellon & Teixeira (1950), the prevalence of esquistossomose was esteem in 10% of the population of the studied endemic area in the country. The results of this inquiry evidence greaters prevalences for the states of Alagoas, Sergipe, Pernambuco and Bahia. In the State of the Bahia, in study based on secondary data of four decades, Barreto and cols7 they had found average prevalence of 15,6% in the year of 1950 and of 9,5% in 1994 e, according to same authors, the urbanization and the migration are associates to this variation of the prevalence, also indicating entailing enters the process of the population dynamics and the dissemination of the illness in the diverse spaces that constitute the bahian territory.