…Biblical biowarfare: pollution, bugs, frogs and diseases

[The Leaven – exploring the relationship between science and religion (cont)]

In the Old Testament the role of mediator between deities, the pharaohs and Hebrews was entrusted upon Moses. Moses was born to a Hebrew mother who, out of compassion disobeyed the Egyptian Kings order to drown him at birth. When he was a few months old she placed him in a basket made of bulrushes and left him on the banks of the River Nile in the hope that he would be saved from drowning. He was rescued from the Nile by the daughter of the Egyptian King and named Moses. The name, Moses, could be derived from the Egyptian noun Moseh, to beget a child. The Bible however gives an alternative interpretation: The Princess who found the child is thought to have named him Mosheh after the Hebrew word for pulled out, mashah:

She said to herself, “I pulled him out of the water, and so I named him Moses.”
[Ex 2. 10]

According to the Bible good fortune continued to shine on Moses; he  enjoyed the privileges of a  life within the Pharaoh’s court. Although Moses was raised as an Egyptian he still sympathised with the oppressed Hebrews on account of his heritage. His devotion combined with a sense of morality led him to fatally attack a slave driver. Fearing retribution, he fled from Egypt to the Sinai Peninsula.

God appears to Moses through a burning bush. Painting by Pluchart, 1848.

During his exile he encountered a religious sign or illusion, the burning bush, and heard instructions from the Lord.

Moses saw that the bush was on fire but that it was not burning up.
“This is strange,” he thought. “Why isn’t the bush burning up? I will go closer and see.”
When the Lord saw that Moses was coming closer, he called to him from the middle of the Bush and said, “Moses! Moses!” he answered, “yes, here I am.”
God said. “Do not come any closer. Take off your sandals, because you are standing on holy ground. I am the God of your ancestors, the God of Abraham, Isaac and Jacob.”
So Moses covered his face, because he was afraid to look at God. Then the Lord said, “I have seen how cruelly my people are being treated in Egypt; I’ve heard them cry out to be rescued from their slave drivers. I know all about their sufferings, and so I have come down to rescue them from the Egyptians to bring them out of Egypt to a spacious land, one which is rich and fertile…”
[Ex. 3. 2-8]

It was a common occurrence within many ancient religions to enter into personal relationships or covenants with deities
through fire or bright lights. In Genesis[15. 12], Abraham witnesses the presence of a deity through a burning light within animal carcasses and also makes a covenant:

When the sun had set it was dark, smoking fire pot and a flaming torch suddenly appeared and pass between the pieces of the animals. Then and there the Lord made a covenant with Abraham. He said, I promise to give your descendants all this land from the border of Egypt to the River Euphrates.”

When Moses returned to Egypt, he told the Hebrews that the Lord had instructed him to lead them out of Egypt [Ex. 3, 16-18]:

The God of your fathers has appeared to me- the God of Abraham, of Isaac, and of Jacob; and he has said to me: I have visited you and seen all that the Egyptians are doing to you. And so I have resolved to bring you out of Egypt where you are
oppressed, to a land where milk and honey flow.

Moses first of all tries to reason with the King of Egypt to free the Hebrews.  His attempts fail and cause the Egyptian King to retaliate by increasing the workload of the slaves. Moses then tries warning the King through a display of awesome magic powers and through summoning a number of devastating plagues.The Biblical account of the exodus from Egypt is the centre of much scientific speculation especially in respect to the plagues that were summoned by the Lord through Moses in order to secure the freedom of the Hebrews [Lev. 7-10].

  • In the first plague Moses accompanied by Aaron turned the waters of all the rivers in Egypt to blood. The fish died and the water was so foul that it could not be drunk.
  • Seven days later Aaron and Moses summoned frogs to swarm the land and the Pharaohs palaces.In desperation the Pharaoh agreed to Moses request to let his people go into the desert to make animal sacrifices to the Lord. The frogs died, were piled into heaps and began to reek.
  • When the plague subsided the Pharaoh broke his promise so Moses through Aaron summoned a plague of mosquitoes. The Pharaoh still refused to relent so Moses and Aaron, at the will of God, summoned further plagues.
  • Swarms of gadflies infested the Pharaohs palace and the houses of his courtiers and into the land of Egypt but not to the land of Goshen were the Hebrews lived.
  • Then a deadly plague killed Egyptian livestock.
  • This was followed by a sixth plague in which Moses took soot from a kiln and threw it in the air, when it landed on the Egyptians it brought out boils that turned into sores. Still the Pharaoh was resolute.
  • Moses then summoned plagues of hail, locusts and darkness. Even when subjected to fear and threats the Pharaoh was determined not to lose his work force, so finally Moses and Aaron threatened to kill the Egyptians first born.

There does seem to be a structured and logical process of ecology behind the sequential appearance of each of the plagues. What is also interesting, and the foundation for further speculation, are that the plagues  made a clear distinguish between Egyptians and Hebrews:

The houses of the Egyptians will be full of flies, and the ground will be covered with them. But I will spare the region of Goshen, where my people live, so that there will be no flies there.
[Ex. 8.23]

It is quite evident from the chapters of Exodus dealing with the plagues that there is a great void between the customs and social behaviour of the two populations. For instance, when Moses is pleading with the King to let his people go, he asks if they can travel into the desert to make sacrifices of animals, so that they will not offend the Egyptians:

If we use these animals and offend the Egyptians by sacrificing them where they can see us, we will be stoned  to death. We must travel three days into the desert to offer sacrifices to the Lord our God, just as he commanded us.
[Ex. 8.26-27]

They also lived in different communities the majority of the 2.5 million Egyptians lived in the Nile Delta whereas the Hebrews occupied quarters in the land of Goshen. This type of segregation could have possibly led to a different epidemiology as far as communicable diseases are concerned. The signs from God summoned by Moses, rivers of blood followed by plagues of frogs, gnats, flies, boils and the animal disease, may have happened as a consequence of a natural course of events. It is not unreasonable to suppose that polluting a river could cause frogs to evacuate then subsequently die from dehydration or disease, the decaying bodies could then lead to an out break of flies which would then transfer disease causing organisms from the rotting carcases to animals and humans.

Naturally, there are a number of interesting scientific hypotheses that try to rationalize these events. Ancient Egyptian papyri (London Medical Papyrus) give details of an occasion when the water of the Nile turned red and acidic. Fish died, the waters were undrinkable and burnt the skin. The papyri also mention that pests infected the open wounds and that these pests had a larvae and adult stage, corresponding to the gnats and flies in the Biblical version of the plagues. Volcanic eruptions occurring around the same time are thought to have deposited sulphates in the Nile. The clouds of darkness and hail are perhaps associated with a violent volcanic eruption. Another theory suggests that the blood coloured Nile could be due to a bloom of toxic phytoplankton that produced a red tide forcing frogs onto the riverbank. The frogs eventually died from desiccation leaving a plentiful supply of carrion to attract insects like Rove beetles and gadflies. Outbreaks of insect would have occurred leading to plagues of disease that would infect animals and humans.

There is also the possibility, of course, that Hebrews polluted the Nile with the blood of sacrificed animals and this led to the subsequent chain of events. The final warning that Moses gives the King is that a plague would lead to the death of every firstborn in the land of Egypt. Firstborn children seemed to have some kind of symbolic significance and perhaps participated in a unique ritual or practice that made them more vulnerable to disease then the rest of the population. Alternatively some animal diseases that spread to humans can cause miscarriages, the most notable of these being Brucellosis, which attacks animal tissues with a high erythritol content, a sugar found in mammary glands and the uterus. Brucellosis could have been a secondary infection in cattle that were already in ill health following other diseases such as anthrax. If the Egyptians had contracted this disease from cattle it would have resulted in stillbirths in humans and animals.

In Eastern folklore there is a strong tradition that plagues could be summoned by magical powers. These type of accounts would undoubtedly be exaggerated through narration as the events summoned by Moses gradually increase in number through subsequent versions of the Pentateuch from seven in an early account to ten in the complete account [Ex. 7-12]. The seven events in the original account included turning the water of the Nile to blood then summoning scourges of frogs, flies, cattle plague, hail, locusts and the death of the firstborn. In the version revised by the Holy Priests in Jerusalem plagues of gnats, boils and darkness are added to the list.


…that’s not acne, it’s the wrath of God

[The Leaven – exploring the relationship between science and religion (cont)]

Communities in the Biblical era knew nothing about the causative agents of disease. Despite this, the Old Testament contains valuable guidance on how to cope with the challenges presented by contamination and disease. In this period many extremely unpleasant diseases, such as smallpox and bubonic plague, would have been endemic and had the potential to wipe out entire communities. Unsurprisingly, epidemics were thought to be plagues summoned by supernatural beings, especially as some sectors of a population would appear to have greater vulnerability than others. When Ethiopian soldiers occupied the city of Mecca in 568 AD they were so afflicted by a severe disease that the conflict was forced to end. The migrating population had no acquired immunity to this disease, which was believed to be smallpox.

Smallpox was a viral infection and a major scourge at the time the Bible was written. The first detailed observations of it were recorded in 910 AD by al-Razi, an Arabic physician. Al-Razi was in charge of a hospital in Baghdad where he wrote a treatise on smallpox. His research gave some accurate epidemiological descriptions of the disease. For instance he noted that it was seasonal, occurring predominantly in the spring and he also distinguished the symptoms of smallpox from those of measles. The treatise was translated into Greek and Latin enabling Europeans to prepare for the disease as it spread towards their continent and other parts of the world. It is not clear if smallpox was as virulent a disease in ancient civilisation as it is today, but there were clearly references to dreaded skin diseases and plagues of boils in the Old Testament. Additionally, facial lesions that could have been caused by smallpox were found on the mummified body of Ramses V, who died as a young adult. As the pustules were still clearly visible the disease may have been the cause of his death. Smallpox eventually spread globally as a consequence of migration and trading. The Spanish introduced smallpox to South America in 1507 where members of an enslaved African community spread it to the local population. The disease spread around the Caribbean and in 1520 it was transferred to Mexico. It was believed that a member of a Spanish crew was suffering from the disease when one of their ships landed in Mexico. As it was an entirely new disease the indigenous people had no natural immunity or experience in dealing with it. When it arrived from Europe it practically obliterated the indigenous people of Mexico, the Yucatan and Guatemala.

Plague in the Bible. Painting by Matthias Gerung c1530-1532

As with smallpox, bubonic plague also spread globally through migration and trading. The causative agent of bubonic plague is the bacterium Yersinia pestis. It is a characterised by dark buboes, fevers and vomiting. Whereas smallpox is restricted to humans, bubonic plague could afflict both humans and animals resulting in a higher number of transmissible routes. Recent research believed that the disease originated from Nile rats and was then transferred to Black or Ship rats via its vector the tropical rat flea. It is thought that the disease may have become more virulent in the Black rat as it seemed to cause more fatalities in Europe than in the countries it originated from, or perhaps this was quite simply because the Europeans had no innate immunity towards the disease, a similar scenario to the one that allowed smallpox to devastate the indigenous population of the Americas. In 439 BC, an epidemic of bubonic plague that originated from Ethiopia arrived in Europe; the Greek, Thucydides, who survived the disease, recorded its progress. It caused the death of one in three people in Athens, including the statesman Pericles, and is thought to have contributed to the fall of classical Greece.

There is no doubt that plagues and skin diseases preoccupied ancient societies. Hebrews believed that illness and disease were the wrath of a powerful deity and therefore religion playing a prominent role in disease management. The High Priest had the unenviable responsibility of devising and implementing a programme of disease prevention by compiling and implementing rules and regulations:

The Lord gave Moses and Aaron these regulations. If anyone has a sore on his skin or a boil or an inflamation which could develop into a dreaded skin-disease, he shall be brought to the Aaronite priest. The priest shall examine the sore, and if the hairs in it have turned white and the sore appears to be deeper than the surrounding skin, it is a dreaded skin disease, and the priest shall pronounce the person unclean.
[Lev. 13. 1-4].

These regulations were a type of quarantine to prevent the spread of disease ensuring that infected individuals were segregated from the community until they were proven to be clean:

A person who had a dreaded skin-disease had to wear torn clothes, leave their hair uncombed, cover the lower part of their face, and call out, ‘Unclean, unclean!’ They remained unclean as long as they had the disease, and they had to live outside the camp, away from others, as did any other person that came in contact with an unclean person.
[Lev. 13.45-46]

Tuberculosis was another affliction that was very widespread and seemed to occur frequently. Evidence of it has been found in human skeletal remains. The bacteria that caused this disease are similar to the Bacilli that give rise to leprosy. Therefore people who had managed to survive tuberculosis were more likely to have immunity to leprosy, which was thought to be fairly rare at the time despite it being mentioned frequently in the Bible. When leprosy is mentioned in the Bible it is probably also referring to other more common infectious conditions such as ringworm, a fungal infection that gives rise to white hairs within infected areas, as described in the text of the Old Testament:

If anyone has a boil that has healed and if afterwards a white swelling or a reddish white spot appears where the boil was, he should go to the priest. The priest shall examine him, and if the spot seems to be deeper than the surrounding skin and the hairs in it have turned white, he shall pronounce him unclean. It is a dreaded skin disease that started in the boil.
[Lev. 13. 18-20]

Another Bacillus that caused skin lesions and may well have been the disease referred to as boils in the Old Testament, was Bacillus anthracis, the causative agent of anthrax.  B. anthracis is nearly always fatal when inhaled leading to respiratory failure and septic shock within two to three days. Prognosis is also not good when the B. anthracis is digested after eating infected meat. Cutaneous anthrax is the most common form of the disease accounting for 95 percent of all cases, if untreated the fatality rate is 5-20 percent, relatively low when compared to the other forms. Anthrax legions only occur in exposed areas, such as the hands and face, and are accompanied by local swelling. Ancient remedies for treating the disease included laying figs directly upon the sore. There may have been some benefit in this as figs have been found to contain a good source of natural antibiotics and vitamin A. Other natural materials with antibacterial properties such as sesame oil and wine were frequently used to dress wounds. The Hebrews discovered that these materials had beneficial properties through trial and error, in much the same way as how they knew that leaven could sometimes be impure.