Devil’s choice: Ricardo Jorge, the ‘Spanish flu’ pandemic and the pneumonization of plague, 1899-1933

The Portuguese hygienist Ricardo Jorge gained some international recognition for his management of the plague outbreak that struck the city of Porto in 1899. However, it would be his experience of the “Spanish flu” pandemic of 1918-1920 that played a key role in his rejection of the rat-flea model of transmission then in force in favor of the greater relevance of interhuman trans mission. This paper aims to explain the evolution of his medical-epidemiological conception of plague, on one hand by analyzing Jorge’s institutional background in Portugal and within international sanitary organizations (Organisation Inter nationale d’Hygiène Publique) and on the other hand by examining his scientific contribution, based on epidemiological and historical data, to the “pneumoni zation” of the disease, especially in relation to emergence mechanisms of epi demic outbreaks (epidemiogenesis). In a series of publications running from 1919 to 1933, Jorge made key contributions to the global redefinition of one of mankind’s most dreaded scourges.