Plagues Speed Up With Each New Outbreak - MedicineNet Plagues Speed Up With Each New Outbreak - MedicineNet Posted: 19 Oct 2020 12:00 AM PDT Latest Infectious Disease News TUESDAY, Oct. 20, 2020 Medieval plague outbreaks in England picked up frightening speed in the 17th century, Canadian researchers report. Their analysis of historical documents covering 300 years showed that outbreaks of the plague doubled every 11 days in London during the 1600s, compared to every 43 days in the 14th century. "It is an astounding difference in how fast plague epidemics grew," said lead author David Earn, an investigator with the Michael G. DeGroote Institute for Infectious Disease Research at McMaster University in Hamilton, Ontario. No published death records were available for London before 1538. So statisticians, biologists and evolutionary geneticists analyzed personal wills, parish registers and data used to monito