The Power of Plagues. Irwin W. Sherman

      The Pharaohs’ Plague

       A look back

The Assyrian and Babylonian literature, as well as the Egyptian papyrus from Kahun written in about 1900 B.C., describe a disease that causes blood to appear in the urine (hematuria). And near the Louvre Museum in Paris there is a stone from ancient Egypt that says, “Anyone who moves this boundary stone will be covered with bloody urine.” Hematuria was described by the father of Arabian medicine, Avicenna (930-1037), in his Canon of Medicine, but the condition, called a-a-a, was recognized much earlier and is mentioned in the Ebers papyrus, dated ~1500 B.C. and named after Georg Ebers, who in 1862 found the paper in a tomb in Thebes, Egypt. There is even a hieroglyphic sign showing a penis dripping fluid, and this too may be blood (Page 44). Such a sign was not considered to be connected with disease, but as a mark of puberty in the male child. Many remedies for this disease are described in the Ebers papyrus, suggesting that this condition was widespread. And in a relief of the tomb of Ptah-Hetep I and Mehou of the Sixth Dynasty at Sakarrah there are figures of fishermen and bargemen with enlarged abdomens—surely representing the pathology of chronic snail fever or blood fluke disease. In 1910, Marc Armand Ruffer examined several Egyptian mummies from the Twentieth Dynasty (1200-1000 B.C.) and found the calcified eggs of the blood fluke in the kidneys of several mummies (Fig. 3.2B). Fossil snails capable of transmitting blood fluke disease have been found in the well water of Jericho. It has been hypothesized that the water was infested with infected snails, resulting in a high level of disease. Too debilitated by disease to defend the city or repair the decaying walls, the people of Jericho were easily defeated by Joshua’s army. Joshua, though unaware of the cause of the disease that contributed to his success, but wanting to prevent its spread, destroyed Jericho and proclaimed a curse on anyone who would rebuild it. The city remained deserted for 500 years. Centuries of recurring drought destroyed the snails, and thus the city has remained free of disease to this day. All this suggests that snail fever has existed in tropical and subtropical parts of the world, but especially in Egypt, since ancient times.

Soon after humans settled down and food production began in the Fertile Crescent (~8000 B.C.), it spread to other parts of Eurasia and North Africa. The plants (as well as the domesticated animals) that formed the basis for agriculture in the valleys between the Tigris and Euphrates Rivers were also cultivated in the Nile Valley of Egypt, and this triggered the rise of Egyptian civilization. These same agricultural practices, though, sustained by the Nile, also sowed the seeds of Egypt’s decline.

      The land of the pharaohs flourished for 27 centuries, and its accomplishments, even today, are truly impressive. When Herodotus, the Greek historian, made a tour of Egypt in 400 B.C., he wrote of “wonders more in number than those of any other land.” And he went on to say that “when the Nile inundates the land all of Egypt becomes a sea and only the towns remain above water. Anyone traveling from Naucratis to Memphis sails right alongside the pyramids, and when the waters recede they leave behind a layer of fertile silt—’black land’—the Egyptians call it, to distinguish it from the sterile ‘red land’ of the deserts. Egypt is the gift of the river.”

      In some ways Nature favored Egypt because, unlike Mesopotamia, which stood on an open plain and was unprotected from marauding tribes, the deserts that bordered the Nile discouraged invasion, and so the people lived in relative security. The villages shared the river and merged into cities. To tap the bounty of the Nile required the cooperation and organization of the people, with social and political structures developing therefrom. All power was invested in the pharaohs, who were both kings and gods. Below the pharaoh was a vast bureaucracy that rested on the shoulders of the workers and the peasantry. Egypt’s people, however, who built enduring stone monuments for their pharaohs, were racked with a debilitating disease, snail fever. And although medical science began in Egypt, the doctors and surgeons could not keep this disease at bay. There is a reason for this: the early civilizations of Egypt and those of the Fertile Crescent (Sumer, Assyria, and Babylon) were based on agriculture, and this agriculture required irrigation and/or natural flooding by the rivers. Irrigation farming, especially in the tropics, created conditions favorable for the transmission of snail fever caused by the blood fluke. Blood fluke disease—the plague of the pharaohs—is not a fatal disease, as is malaria or yellow fever; it is, however, a corrosive disease. And although there may have been a time when the natural flooding of the Nile River made snail fever a seasonal problem, once there was irrigation it became a year-round problem, since infections could be acquired from the standing water in the irrigation channels. Consequently, as William McNeill wrote in his book Plagues and Peoples,

      there was a listless and debilitated peasantry handicapped … for the … demanding task of resisting military attack or throwing off alien political domination and economic exploitation. Lassitude and chronic malaise … induced by parasitic infections was conducive to successful invasion by the only kind of large-bodied predators human beings have to fear: their own kind, armed and organized for war and political conquest.

      McNeill also suggested that the rule of the pharaohs may have been due to the power of the snail and the blood fluke and malaria—the classic plagues of Egypt—which debilitated the populace.

      And so it was that snail fever did its work. By 660 B.C., Egypt became subject to internal political dissension and to attack by their iron-armed neighbors (the Assyrians), and their civilization, based on agriculture and copper weapons, began to collapse. The Persians overran Egypt in 525 B.C. The cause of snail fever, the disease that set the Egyptian civilization on its inexorable downward spiral, was unknown to the ancient Egyptians because the transmission stages of the parasite (eggs, miracidia, and cercaria) are microscopic; in addition, the adult worms themselves are tiny and live within the small blood vessels, and so they were unnoticed for thousands of years.

       Search for the destroyer

      Blood fluke disease, also known as snail fever and endemic hematuria, involves feces or urine, water, snails, and a flatworm. The first Europeans to experience the disease on any scale appear to have been the soldiers of Napoleon’s army during the invasion of Egypt (1799-1801). The symptoms of the disease, bloody urine, were rife among the soldiers. Baron Jean Larey, a military surgeon, noted its high frequency in the men; he believed, however, that the excessive heat during the long marches was the cause. The connection between hematuria and a parasite did not occur until 1851. In that year Theodor Bilharz, a German physician working in Egypt, while carrying out an autopsy on a young man, made a startling discovery: worms were found in the blood vessels, a location never before encountered (Fig. 3.2E). He named the worm Distomum (meaning “two mouths”) haematobium (from the Greek words haema, meaning “blood,” and bios, meaning “to live in”). In 1858 the name was changed to Schistosoma (from the Greek words schisto, meaning “split,” and soma, meaning “body”). Today, blood fluke disease is called schistosomiasis or bilharzia, the latter in honor of Bilharz’s discovery. (During World War I, British soldiers found it easier to call the disease “Bill Harris.”)

In 1851, Bilharz reported that he had seen microscopic eggs with a pointed spine in the female worm (Fig. 3.2C), and in the following year he observed these eggs in the bladder; within the egg he observed a small, motile embryo. He also found that the eggs would hatch to release a small ciliated larva (Fig. 3.2F) that swam around for about an hour and then disintegrated. This work was confirmed in 1863 when John Harley, a London physician, examined a patient with hematuria who had previously lived in the Cape of Good Hope in South Africa. Examining the blood-tinged urine in a drop of water under the microscope, he found schistosome eggs, and several of these hatched to give progeny that swam by using their cilia (Fig.