For anyone who is interested, here is a spreadsheet (version 2.0) of all outbreaks of pestilence known to me attested in written sources, for Italy, from the republic to late empire. Pestilence simply means disease outbreak or epidemic, regardless of biological agent. If you know of others that should be soon the list, please let me know.
I would love to know if you use these data. Please cite as: Kyle Harper, Database, “Pestilence in Italy 500 BCE to 600 CE, version 1.0,” kyleharper.net.
h/t Tilman Hartley for some additions to 2.0.