Also, there's a excellent book, "Plaugues and Peoples", by William H. McNeill that is a fine read if you are in a gloomy mood and wish to feel worse. :)
He chronicals plagues throughout recorded history, and the list from China alone is amazing.
Whoops, that's PLAGUES, not plaugues.
Does he go into the 'sanitary practices' - or lack thereof - by any of those peoples?