History of the Peloponnesian War
Thucydides
Thucydides, Vol. 1-4. Smith, Charles Foster, translator. London and Cambridge, MA: Heinemann and Harvard University Press, 1919-1923.
The disease began, it is said, in Ethiopia beyond Egypt, and then descended into Egypt and Libya and spread over the greater part of the King's territory.
Then it suddenly fell upon the city of Athens, and attacked first the inhabitants of the Peiraeus, so that the people there even said that the Peloponnesians had put poison in their cisterns; for there were as yet no public fountains there. But afterwards it reached the upper city also, and from that time the mortality became much greater.
Now any one, whether physician or layman, may, each according to his personal opinion, speak about its probable origin and state the causes which, in his view, were sufficient to have produced so great a departure from normal conditions: but I shall describe its actual course, explaining the symptoms, from the study of which a person should be best able, having knowledge of it beforehand, to recognize it if it should ever break out again. For I had the disease myself and saw others sick of it.
That year, as was agreed by all, happened to be unusually free from disease so far as regards the other maladies; but if anyone was already ill of any disease all terminated in this.
In other cases from no obvious cause, but suddenly and while in good health, men were seized first with intense heat of the head, and redness and inflammation of the eyes, and the parts inside the mouth, both the throat and the tongue, immediately became blood-red and exhaled an unnatural and fetid breath.
In the next stage sneezing and hoarseness came on, and in a short time the disorder descended to the chest, attended by severe coughing. And when it settled in the stomach, that was upset, and vomits of bile of every kind named by physicians ensued, these also attended by great distress; and in most cases ineffectual retching followed producing violent convulsions, which sometimes abated directly, sometimes not until long afterwards.