After the death of his mentor in 1917, Chagas accepted Cruz's directorship of the institute, a post he held until his death in 1934. From 1920 to 1924, he became the director of the Department of Health in Brazil. Chagas was very active in organizing special health-care and prevention services and campaigns for the Spanish flu epidemics, sexually transmitted diseases, leprosy, pediatrics, tuberculosis, and rural endemic diseases. He created a nursing school and was the founder of the concept of sanitary medicine, the first chairman of tropical medicine and the graduate study of hygiene.