Diagnosis of schistosomiasis is made by the examination of stools and urine under the light microscope and the finding of eggs. Sometimes this visual test is supplemented by biopsy and immunologic methods. Preventive measures include education of the population regarding the means for preventing transmission, the treatment of infected persons, and the control of the snail vector using molluscicides. In some cases (e.g., growing rice), avoidance of contact may be impossible. Human exposure can be reduced, however, by the provision of a safe water supply for bathing and washing as well as by the sanitary disposal of human wastes. Other measures may be lining of irrigation channels with cement to discourage snails; intermittent irrigation of rice paddies to disrupt the life cycle; or storage of water away from snails for 2 or 3 days, a time that exceeds the survival time of the miracidia.
The earliest treatment for the disease, developed in 1918, required the intravenous administration of an antimony compound (tartar emetic). In 1929 intramuscular injections of another antimony compound, stibophen, were used, but the cure rates were not as good as with tartar emetic, and both drugs showed severe toxic reactions and sometimes resulted in death. Later, an oral drug, niridazole, was introduced (1964), but it wasn’t until the 1970s that a truly effective drug with low toxicity was developed: praziquantel (trade name: Biltricide). There is no preventative vaccine or drug.
The development of new drugs for the treatment of schistosomiasis can be a long and expensive undertaking. Further, determination of drug efficacy and safety may require extensive animal and human testing. One such heroic effort is worthy of mention. Claude Barlow, an American physician, volunteered for a chemotherapy trial and exposed his abdomen to 224 cercaria, and when cercarial dermatitis developed, he knew he had been infected. He came down with severe schistosomiasis, which required many intravenous injections of tartar emetic for cure. In his old age Barlow wrote: “even today I shudder every time I see a hypodermic needle.”
Today, with hindsight, it is easy to understand why those living in ancient Egypt were unable to control schistosomiasis, but why, 2,000 years later, are we still failing? There are certainly economic constraints such as the cost of pesticides to kill the snails and the cost of drugs, as well as the necessary infrastructure for providing clean water and sanitary disposal of wastes, but in the final analysis it is the habits of the human population that are of critical importance to the elimination of this disease. Since there is no animal reservoir, humans are required for the perpetuation of the disease. As long as infected individuals continue to urinate and defecate in the same waters where the vector snail lives, and to expose their bare skin, there will be blood fluke disease.
The Plague of Athens
The valleys of the Nile and Tigris-Euphrates spawned the civilizations of Egypt and Mesopotamia. The flat fertile valleys made it easier to subject the populations to a single ruler and to oversee individuals so that each had a prescribed role in the society. As a consequence, there emerged in the Fertile Crescent and Egypt a unified system of kingdoms. The different geography of Greece gave rise to another kind of sociopolitical system. Greece, the southernmost extremity of the Balkan landmass, is composed of limestone mountains separated by deep valleys and is cut almost in two by the narrow Corinthian Gulf. The southwestern peninsula was called Peloponnesia, and the northeastern part was called Attica. East of the mainland are the islands of the Aegean Sea; to the south is Crete. In Greece, because the small populations were separated from one another by mountains and the sea, central control was impossible and individuals were not compelled to become specialists but rather masters in a range of accomplishments of hand and mind. Greece, smaller in area than Florida, was never able to support more than a few million inhabitants, but it has played an enormous role in the history of Western civilization. We see some of this today in their monuments, sculptures, paintings, and writings, and we speak of the “glory that was Greece.” Indeed, the prestige of the Greeks in the arts and their ideas on medicine, astronomy, and geography were accepted with unquestioning faith until the 17th century, when a new scientific spirit of experiment and inquiry came into being.
The land and the climate of Greece were unsuitable for farming grains, and as a result, the economy rested on the large-scale movement of goods by ship: the Greeks planted vines and olive trees and produced wine and oil, and these were exchanged for grains and other less valuable commodities. Indeed, an acre of land with vines and olive trees could yield a quantity of wine and oil that could be exchanged for an amount of grain requiring many acres for its production. The outlying communities on the Mediterranean and Black Seas that provided these less valuable commodities were called by the Greeks “barbarians,” from the Greek word barbaros, meaning “foreign” or “uncivilized.” It was the barbarian societies that provided grain, metals, timber, and slaves in exchange for oil and wine and so contributed to the emergence of the Greek civilization.
The Greeks had an unshakable belief in the worth of the individual. While to the east there were absolute monarchies, the Greeks evolved a democratic society where each individual was respected and counted. What developed were states consisting of a city and its surrounding lands whose inhabitants, citizens (literally “those living in the city”), were valued. (Not all individuals, however, were citizens; slaves and women did not have the same rights.) The city-states of Greece, insulated from the barbarians, consisted of urban centers dedicated to commercial transactions with limited local farming; as they prospered, the population grew. The inhabitants of the city-states were healthy but naive to the diseases that were endemic in the Middle East, and this was to prove decisive in the Peloponnesian War.
Before the Greeks of historical times (~750 B.C.), civilizations had flourished in Mycenae (1600 to 1200 B.C.) and before that in Crete (the Minoans). Later, the Dorians invaded from the north, destroying the Mycenaean cities and society, and this conquest ushered in for 450 years (1200 to 750 B.C.) what is called the Dark Age. At the close of the Dark Age there emerged two powerful city-states that were essentially military garrisons governed by a commander and his captains. These were Athens (in Attica) and Sparta (on the Peloponnesus). Sparta was settled by the Dorians, and Athens gave refuge to Mycenaeans. Each city-state represented opposing philosophies: stern military discipline in Sparta versus intellectual and political freedom in Athens. As the population of Athens grew too large for the limited space of Attica, the Athenians began sailing out of their port of Piraeus to colonize the Aegean islands and the western coast of Asia Minor (in what is today Turkey). These Greek colonies were called Ionia.
Belief in liberty and freedom made Greek city-states resist domination by others. And since each state had its own habits, rules, and government, the loyalties of the citizens were to a particular city-state, the polis. (People engaged in the civic life of the polis give us the term “politics.”) As a consequence, war between Athens and Sparta was inevitable. In 431 B.C. the Peloponnesian War began between these two city-states, and it lasted for 27 years. The cause of the war was probably economic, although of this we cannot be certain, but what is known is that its outcome was determined by disease.
The Greeks, apparently against all odds, managed to defeat the numerically far superior Persian forces in two battles, in 490 B.C., at Marathon, and again in 480 B.C., in the great naval battle of Salamis. This led a number of Greek city-states to join together with Athens in a sea league both to punish the Persians and to obtain recompense for the cost of the war. In time, however, Athens turned this league into an instrument of its own imperial power, appropriating the funds of the league for the creation of monuments of imperial splendor (notably, the Parthenon). This naturally provided a focal point for the jealousies and rivalries of the various city-states, especially Sparta.
Corinth was a commercial and colonial power and an ally of Sparta. Because of this, its interests were in competition with those of Athens. Athens began to interfere in the affairs of Corinth. Corinth naturally objected and threatened Athens, so in retaliation Athens began an embargo of Corinth and other city-states on the Isthmus of Corinth. This crippling
