At http://phys.org/print364704390.html … new research seems to indicate bubonic plague has bedevilled human populations for much longer than consensus has allowed, even as early as the 4th and 3rd millenniums BC (and possibly even earlier when they get to research back further). The migration of people during the Bronze ages has been fingered as one of the culprits.
In the Book of Samuel, in the Bible, an outbreak of plague is described that struck the Philistines (presumably not long after the end of the Late Bronze Age, or as part of the drama associated with that destruction event). The migrants in this case are the Philistines (and others) that washed up on the shores of the eastern Mediterranean. They did not necessarily bring it with them but may not have experienced it in a virulent form until arriving in Canaan. Of course, if you take on board what Mike Baillie said in his book, 'New Light on the Black Death; the cosmic connection', you might discard blaming the migrants and look at plague with an origin in comet debris, affecting rodents as much as humans. This is of course a theory as the plague is otherwise well researched – see for instance John Kelly, The Great Mortality, Harper Collins:2013 – but beware as he studiously ignores anything that he might think ignorant (coming from medieval sources that talk about thick clouds, dimmed suns, and earthquakes and fire). Baillie deals with the same literature in an opposite manner.
The Philistine plague involved swellings in the groins which various people, qualified and unqualified from a medical point of view, have compared to bubonic plague. It is also known from Armenia in the 10th century BC. The researchers suggest the plague changed its nature around the end of the Late Bronze Age (when population levels dropped significantly).
The same story is at www.eurekalert.org/pub_releases/2015-10/cp-pih101515.php … where we learn that bubonic plague has been identified not just with the Black Death epidemic but with Justinian's Plague of the 6th century AD. It also has factors in common with the Plague of Athens in the 5th century BC (denied by many others) and the Antonine Plague of the 2nd century AD (also refuted by others). So far, research has only gone back as far as the beginning of the Early Bronze Age (which followed another event, possibly cosmic in nature) but the ambition is to extend the research back as far as they can go.