There was definitely an interesting theory propagated on the internet, back when the 2014-15 Ebola outbreak was still a major concern, that the Plague of Athens mentioned in Thucydides II.49-52 was Ebola (I think it specified the Marburg strain). I respectfully disagreed, but it does present curiously like a hemorrhagic fever. Funnily enough, published scholars agree with me:
Especially in the past one hundred years, physicians have joined philologists in speculating about what micro-organism caused the epidemic. One scholarly analysis has succeeded another, arguing that the cause was smallpox or measles, typhus or scarlet fever, bubonic plague or pneumonic plague, ergotism, leptospirosis or Tularemia, and, more recently, Marburg-Ebola virus, Rift Valley Fever, or influenza complicated by staphylococcal infection. proposed etiology fit the description in certain respects, but each had its difficulties as well, thus accounting for the continuing search for the true cause. (Morgan, “Plague or Poetry? Thucydides on the Epidemic at Athens,” Transactions of the American Philological Association, pp. 197–198)
The theory as it went around in 2014-15 was spearheaded, according to the Washington Post, by a scientist, Powel Kazanjian (abstract taken from Oxford Journals, Clinical Infectious Diseases—link at the end of the answer):
This article addresses whether Ebola may have been present in an urban setting in Athens in 430 B.C.E and explores the historical importance of the ancient outbreak. New knowledge from today's West African epidemic allows a more accurate assessment of whether Ebola may have caused the Athenian outbreak than was once possible. The Athenian disease, whose etiology remains unknown, developed abruptly with fevers, abdominal pain, vomiting, diarrhea, dehydration, and hemorrhage. It originated in sub-Saharan Africa and was especially contagious to doctors and caregivers. No remedies were effective. But the few survivors who were re-exposed to diseased patients were not attacked a second time, suggesting protective immunity. What lessons can we learn from the ancient outbreak that bears a clinical and epidemiological resemblance to Ebola? The historian Thucydides, an eye-witness and disease sufferer, wrote how the unsuspecting city panicked as it struggled to handle the rapidly spreading, devastating disease. Moreover, he stressed a theme that has relevance today—fear and panic intensified the disruption of society and damage to the individual that was directly caused by the disease. Moreover, fear amplified the spread of disease. His insights into the destructive nature of fear have remained a signature feature of pestilences that have subsequently caught ill-prepared cities off-guard—Bubonic Plague in medieval times, AIDS in the 1980s and Ebola today. The ancient Athenian epidemic is relevant for today's West African Ebola outbreak because it shows how fear and panic can endanger the individual, our society, and our efforts to handle the disease.
[Emphasis is my own, on symptoms listed by Kazanjian and Thucydides.]
Here are the symptoms as listed in order of presentation by Thucydides (translated by Jowett and Hobbes, compiled by yours truly). Both public domain translations are listed in the sources:
If one overcame the disease: