Who is this Thomas Short that the writer keeps quoting, and which of his works are the quotes taken from? In any case, there have been similar events both before and since Justinian's plague.
In 430 BC, Athens was struck by a plague, although historians are uncertain as to what disease was involved.
The bubonic plague epidemic that began in AD 1347 killed from one quarter to one half of the population of Europe, and periodic outbreaks continued through the seventeenth century. There is evidence that the bacterium that caused this plague is related to the one that caused the plague of Justinian's day.
The Spanish Flu in 1918 was pretty damned bad. It killed a ton of folks all over the world.