The Plague of Athens

Disclaimer: The publisher wishes to note that he has been warned that this series may be ill-conceived and in bad taste.  If, for whatever sick reason, you still wish to proceed, know that I was warned and advised against this.
The Plague of Athens was not the first plague in human history, but it's the earliest one with a surviving reliable historical record.  The year was 430 BC, and those goofy Greeks were at each others throats in a little thing we're going to call the Peloponnesian War.  For a bunch of complicated reasons that basically boil down to Athens becoming the dominant empire in the Mediterranean and Sparta (whose balls were always tingling for a war anyway) deciding that was stupid.  Together with their respective alliances, Spartans and Athenians were having so much fun killing each other that, like the proverbial little sibling, Mother Nature decided she wanted to get in on the fun, at which point the Greeks decided it wasn't fun anymore.  Actually, Mother Nature was mainly killing Athenians, which was super unfair since up until then they had been winning.  The Spartans were a lot better at killing on land, so the Athenians had decided to play a game of 'sardines' in their city while their superior navy did the dirty work, but something about bringing all those people in from across the countryside to hang out in an urban environment with poor sanitation resulted in an excellent breeding ground for disease.  The Athenians didn't know what exactly had hit them.  The disease was believed to have entered their ports after having already spread through Northern Africa, and as their prayers for deliverance went unanswered, Athenians began to believe the gods had abandoned them in favor of Sparta.  A contemporary record of the plague comes from Thucydides, who reports a range of fairly standard symptoms like fever, sore throat and diarrhea (but not the funny kind where there's lots of farting and you live to tell about; it was the unfunny kind where you get dehydration and malnutrition and die), but no one knows exactly what it was according to modern medicine.  The most popular theory is typhus, or an Ebola-like viral hemorrhagic fever.  At first, the plague seemed to be a little bit of a blessing in disguise as far as the war was concerned, because when the Spartans saw Athens burning mountains of dead bodies, they retreated for fear of contracting the disease themselves.  Fancy that, Athens causing those big, tough Spartans to retreat without even trying?  But then the disease killed Athens' brilliant general and community leader Pericles, along with an estimated quarter or more of the population (75,000-100,000 people).  People were dying so fast that those still around decided that good behavior wasn't worth it anymore if they were going to die before having a good reputation could pay off, resulting in a total breakdown in social order.  Athens got their asses handed to them by Sparta once all was said and done, and frankly, after having spent so much time kicking the crap out of each other, the Spartans just weren't cut out to perpetuate the golden age of Greece.  To this day, people still sometimes have diarrhea after eating Greek food, in commemoration of the Plague of Athens.