THE SPREAD of communica,ble diseases in schools ha,s been studied repeatedly because personal contacts in schools have distinctive characteristics. This pa,per records the flow of variola minor (alastrim) through a primary day school during an epidemic in a school district of Sao Paulo, Brazil. This epidemic comprised 54 cases. It had a very limited spread in the general environment of the district despite deficient or a complete la,ck of preventive measures (1), but its spread was rather wide in most households where infection was introduced. Virus isolations, antibody titrations and epidemiologic data (1) definitely identi-fied the disease while clinical findings (2) were typical of variola minor.