Revisiting the Medieval Black Death of 1347–1351: Spatiotemporal Dynamics Suggestive of an Alternate Causation

Abstract

Recent research points to multiple inconsistencies regarding modern Yersinia pestis (in Bubonic, Pneumonic, or Septicemic Plague variants) as a causative agent for the Medieval Black Death (MBD). Published arguments at odds with a Y. pestis‐caused epidemic include differences in recorded periodicity, seasonal mortality peaks, relevant biogeographical details, genetic findings, and spatiotemporal dynamics, among other inconsistencies. Here, we describe and expand on some of the recent literature noting these items. In addition, we discuss preliminary research related to our recently published theory, in which we agree with research suggesting that the MBD was caused by a virus, not a bacterium, and elucidate our contention that seasonal changes and medieval human trade patterns controlled the timing of peak mortality during the MBD and subsequent ‘plagues’. Epidemic evidence from the first epidemic wave and later outbreaks is presented in support of our hypothesis.

New insects feeding on dinosaur feathers in mid-Cretaceous amber

“…Ectoparasitic insects cause discomforts or sickness of hosts, reduce production of livestock, and damage avian feathers, etc 2,3 . More seriously, ectoparasites transmit diseases as vectors 4 , having resulted in catastrophic illnesses and deaths in human history 3,5 . Two major groups of extant ectoparasites, Phthiraptera (true lice), and Siphonaptera (fleas), have attracted much attention from scientific community mainly due to their medical and agricultural significance.…”

Bloodlines: National Border Crossings and Antisemitism in Weimar Germany

“…Another major methodological concern stems from endogeneity or reverse causation bias. Historically, Jewish migration has played an important role in the construction of trade routes, which frequently included roads that cross-cut Weimar’s borders (Welford and Bossak 2010). We also know that in the centuries following the plague, Jewish migration was at times driven by outbreaks of anti-Jewish violence (Johnson and Koyama 2019).…”

“…To rule out worries that antisemitism produced border crossings through legacies of forced long-distance migration that took place after the plague, I draw on pre-Black Death road data collected by epidemiologists (Welford and Bossak 2010) to construct an instrumental variable. Based on a wide range of sources, scholars interested in the social transmission of the Bubonic plague have constructed fine-grained data on medieval road networks from before the Black Death’s initial outbreak and predating the first major waves of antisemitism.…”

GDP effects of pandemics: a historical perspective

“…“Black Death”, “Black Death migration”, “Bubonic plague”, “List of epidemics”, “Pandemic” and “Second plague pandemic” Wikipedia articles; Gould and Pyle ( 1896 ), Payne ( 1911 ), Biraben ( 1976 ), Horrox ( 1994 ), Austin Alchon ( 2003 ), Benedictow ( 2004 ), Bray ( 2004 ), Hays ( 2005 ), Deleo and Hinnebusch ( 2005 ), Hays ( 2009 ), Cohn ( 2010 ), Gottfried ( 2010 ), Hatcher ( 2010 ), Welford and Bossak ( 2010 ), Byrne ( 2012 ), Aberth ( 2013 ), Ziegler ( 2013 ), Cesana et al ( 2017 ), Karlsson ( 2020 )…”