Mathematical Model Developed at YSPH Provides New Insights into Deadly Bubonic Plague


The bubonic plague, transmitted by fleas from rats to humans, has caused major disruptions throughout history, from the Byzantine Empire to the Victorian era. Plague—from natural sources and as an agent of bioterrorism—still poses a threat today, leading scientists to look to the past to understand how interactions of fleas, rats and humans can wreak havoc by spreading the disease.

A new Yale School of Public Health study published in the Proceedings of the National Academy of Sciences uses a mathematical model to understand the joint effects of climate on plague-carrying fleas and the evolution of plague resistance in rats. Based on a set of historical experiments and observations from the plague epidemics of colonial India, the analysis sheds light on how rapid evolution in response to disease impacted one of the plague’s most severe outbreaks.