Science reports:

Although the past may not presage the future, epidemic history illuminates how change unfolds. “Historians often say that what an epidemic will do is expose underlying fault lines,” says Erica Charters, a historian of medicine at the University of Oxford who is studying how epidemics end. But how we respond is up to us. “When we ask, ‘How does the epidemic change society?’ it suggests there’s something in the disease that will guide us. But the disease doesn’t have agency the way humans do.”

Past epidemics have spurred scientists and physicians to reconsider everything from their understanding of disease to their modes of communication. One of the most studied, the bubonic plague, tore through Europe in the late 1340s as the Black Death, then sporadically struck parts of Europe, Asia, and North Africa over the next 500 years. Caused by bacteria transmitted via the bites of infected fleas, the plague’s hallmarks included grotesquely swollen lymph nodes, seizures, and organ failure. Cities were powerless against its spread. In 1630, nearly half the population of Milan perished. In Marseille, France, in 1720, 60,000 died.

Yet the mere recording of those numbers underscores how medicine reoriented in the face of the plague. Until the Black Death, medical writers did not routinely categorize distinct diseases, and instead often presented illness as a generalized physical disequilibrium. “Diseases were not fixed entities,” writes Frank Snowden, a historian of medicine at Yale University, in his book Epidemics and Society: From the Black Death to the Present. “Influenza could morph into dysentery.”

The plague years sparked more systematic study of infectious diseases and spawned a new genre of writing: plague treatises, ranging from pithy pamphlets on quarantines to lengthy catalogs of potential treatments. The treatises cropped up across the Islamic world and Europe, says Nükhet Varlık, a historian of medicine at Rutgers University, Newark. “This is the first disease that gets its own literature,” she says. Disease-specific commentary expanded to address other conditions, such as sleeping sickness and smallpox. Even before the invention of the printing press, the treatises were apparently shared. Ottoman plague treatises often contained notes in the margins from physicians commenting on this or that treatment. [Continue reading…]