Memories of Memórias: shaping a century of plague research and public health policy in Brazil

Plague, caused by Yersinia pestis, remains a historically significant and reemerging zoonotic threat worldwide. Often erroneously considered a medieval relic, the disease persists in natural foci, including Brazil, where it was introduced in 1899 via maritime trade. Over the past 125 years, the country has experienced cyclical outbreaks concentrated in the northeast, where ecological conditions support enzootic transmission among wild rodents and their fleas. While improved surveillance and control have reduced human cases in recent decades, the pathogen’s zoonotic nature and potential for rapid spread in a changing climate underscore its enduring public health relevance. Memórias do Instituto Oswaldo Cruz (MIOC), one of Latin America’s foremost tropical medicine journals, has been instrumental in documenting and shaping the course of plague research in Brazil. Its archives provide a unique chronological record, from pioneering studies on serum production and reservoir ecology to modern molecular analyses of bacterial virulence. This perspective synthesises the seminal contributions published in Memórias that have defined our understanding of plague in Brazil, identifies critical knowledge gaps that persist, and discusses emerging challenges in an era of climate change and shifting zoonotic disease dynamics.