Rhetorical exaggeration vs. evidence
Smallpox epidemic of 1520 “raged across the continent”, but note how slowly it spread from Veracruz to Mexico City, 300 miles, 3 to 5 months (May to September or October).
“In Mexico, ever since 1520, the natives had suffered from severe smallpox epidemics recurring every seventeen or eighteen years.” --Stearn and Stearn, 42.
Yet, of 17 colonial epidemics to 1745 listed by the chronicler Cayetano Cabrera y Quintero only 3 are for smallpox.