what would an infectious diseases physician have … limmud-1.pdf• boils, with a current outbreak...

What would an Infectious Diseases Physician have done

to help Pharoah cope with the

plagues?

Andrew Morris2007.12.02

11:15

Overview

• What is the traditional interpretation of the plagues?

• What are alternate understandings of the plagues?

• Do we have modern-day versions of the plagues?

• What would an infectious diseases physician have done for Pharoah?

The 10 Plagues

I. Water to blood

“Take thy rod, and stretch out thine hand upon the waters of Egypt, upon their streams, upon their rivers, and upon their ponds, and upon all their pools of water, that they may become blood; and that there may be blood throughout all the land of Egypt, both in vessels of wood, and in vessels of stone.”

The 10 Plagues

II.Frogs

“And if thou refuse to let them go, behold, I will smite all thy borders with frogs” “And the river shall bring forth frogs abundantly, which shall go up and come into thine house, and into thy bedchamber, and upon thy bed, and into the house of thy servants, and upon thy people, and into thine ovens, and into thy kneadingtroughs.” “And the frogs shall come up both on thee, and upon thy people, and upon all thy servants.”

The 10 PlaguesIII.Gnats

“Stretch out thy rod, and smite the dust of the land, that it may become gnats throughout all the land of Egypt.”

IV.Flies“Else, if thou wilt not let my people go, behold, I will send swarms of flies upon thee, and upon thy servants, and upon thy people, and into thy houses: and the houses of the Egyptians shall be full of swarms of flies, and also the ground whereon they are.”

The 10 PlaguesV.Cattle disease

“Behold, the hand of the LORD is upon thy cattle which is in the field, upon the horses, upon the asses, upon the camels, upon the oxen, and upon the sheep: there shall be a very grievous murrain.”

VI.Boils“And it shall become small dust in all the land of Egypt, and shall be a boil breaking forth with blains upon man, and upon beast, throughout all the land of Egypt.”

The 10 Plagues

VII.Thunder and HailVIII.LocustsIX.DarknessX.Death of the Firstborn

What is the traditional understanding of the plagues?

• the Torah is to be interpreted literally (acknowledging some difficulties in translation)

• G-d wrought the first 3 plagues throughout Egypt, but the Jews were spared the 4th, 5th, 6th, 7th, and 9th plagues (the 8th plague is unclear, and the 10th plague was dependent on lamb’s blood on the doorpost and eating the Passover offering)

What are alternate understandings of the plagues?

Water turning to blood

• One explanation: the water was contaminated by ash from volcanic eruptions

• Another explanation: red colour reflects a red algal bloom



• red algal blooms are caused by dinoflagellates, which are organisms toxic to the liver in most living species



• the dinoflagellates that cause red tide are Gonyaulax

• these dinoflagellates cause a toxin that is heat-stable, and is ingested by bivalve molluscs (which are found at the bottom of the sea), such as clams, mussels, oysters, and scallops, as well as snails

• ingested (even after cooking) the toxin (saxitoxin) causes “paralytic shellfish poisoning”



• another explanation: “water” refers to urination, and all who drank or washed with water had hematuria, or blood in their urine.

• Schistosoma hæmatobium is a fluke that is found in the Nile river, causing schistosomiasis or “bilharzia”



• patients with Schistosomiasis have infected urinary bladders:

• the adult flukes (“schistosomes”) invade the bladder, lay eggs, and the eggs cause inflammation

• the inflammation results in blood in the urine (“hæmaturia”) and can even lead to bladder cancer

• urinating releases the eggs to the environment

Water turning to blood: What would an infectious diseases

consultant suggest?

• take good care of your bodies of water

• don’t let your citizens bathe or urinate in the Nile

• avoid shellfish

• for those who get schistosomiasis, they need anti-parasitic drugs (praziquantel)

• in your situation, Pharoah, give everyone praziquantel (or let Moses’ people go)


Frogs

• One explanation: the fish got poisoned by the dinoflagellates. With no fish to feed on their eggs, there would be an abundance of frogs/toads advancing to dry land (Egypt) searching for warmth and safety.


Frogs

• From an infectious diseases point of view, frogs on dry land pose some health risks, predominantly Mycobacterium xenopi, a mycobacterium (i.e. similar to Mycobacterium tuberculosis)

• M. xenopi results in lung infections

• an infectious diseases consultant would have been as disgusted by the frogs as anyone else

• in light of the risk of getting infections from the frogs, an ID consultant would have suggested avoiding the frogs and, where indicated, would have treated persons with pneumonia with drugs active against Mycobacterium xenopi

Frogs: What would an infectious diseases consultant suggest?


Gnats• the term can mean gnats,

lice, or any other insects.

• there really aren’t gnats or lice in Egypt now (although there could have been thousands of years ago)

• culicoides, which bite, are known to transmit a wide variety of infections


Gnats• midges such as Culicoides can :

a) transmit virus to humans/animals when having a blood meal

b) acquire new virus by feeding on an infected human/animal

• diseases known to be caused by Culicoides bites include:African horse sickness

Bluetongue (cf “Cattle Disease”)Ephemeral fever

Equine encephalosisMansonella


Mansonella

•unlike the anopheles mosquito, midges (or gnats) bite at all times of day

• the only effective strategy would include wearing protective clothing and insect repellant

• there are no known preventive strategies, apart from trying to treat populations en masse prior to developing symptomatic disease

Gnats: What would an infectious diseases consultant suggest?


Flies• there are a wide variety of fly

which could satisfy the definition of plague--and bring human and/or animal disease with it

• however, most of them are not known to inhabit Egypt

• the stable fly (left), Stomoxys calcitrans, is a fly that would meet the definition of plague


Stable Flies

• stable flies, like Culicoides, are dependent on blood meals for their survival

• they cause irritating bites which can:a) have an allergic reactionb) cause cattle to feed/breed lessc) transmit anthrax to cattle and humans (Plague V)d) predispose to boils (Plague VI)


Cattle Disease

• cattle are suceptible to a variety of illnesses, although, in light of the preceding plagues, the two most likely candidates are “Bluetongue” and “Anthrax”


bluetongue

• Bluetongue Virus (BTV) is an orbivirus which infects cattle bitten by an infected Culicoides

• major signs are high fever, excessive salivation, swelling of the face and tongue and cyanosis (bluish discolouration) of the tongue.

• there is an effective vaccine


Anthrax

• anthrax is a disease caused by the bacterium Bacillus anthracis

• B. anthracis is a spore-forming bacterium whose spores can last for centuries

• it can cause a skin disease (cutaneous anthrax) and a fatal pneumonia (inhalational anthrax)


Anthrax

• anthrax is often inhaled from spores, resulting in pneumonia

• outbreaks among cattle occurs, with the spores germinating in manure

• stable flies can carry the spore, transmitting it to cattle and humans (via a bite)

• for treatment of cutaneous anthrax: penicillin, tetracycline, or ciprofloxacin

• for treatment of inhalational anthrax: ciprofloxacin, penicillin

• for prevention of all forms: vaccination• for control of all forms: quarantine

Cattle Disease: What would an infectious diseases consultant

suggest?

• comes from the latin quaranti giorni, meaning “forty days”

• quarantine was first embargoed on ships arriving from Dubrovnik, in fear of “plague” (The Black Death), a disease caused by Yersinia pestis

• it was subsequently used for many other infectious diseases (incl. leprosy, cholera, and syphilis)

• quarantine was used during the SARS outbreak

Quarantine


Boils

• boils are a collection of white blood cells (“pus”) and bacteria in the skin

• the medical term for boils are furuncles

• almost all boils are caused by the bacterium Staphylococcus aureus


Boils

• boils occur after a person’s skin is colonized with Staph. aureus, and then has a break in it

• the Staph. aureus finds its way under the epidermis, often around a hair follicle, and starts multiplying, causing disease

• a stable fly bite would be a common cause for a break in the skin

• colonization with Staph. aureus may be related to poor hand-washing/personal hygiene

• the primary treatment for boils is incision and drainage (e.g. “lancing”)

• antibiotics may be helpful• because personal hygiene and handwashing is

paramount for preventing boils, an infectious diseases physician would advise Pharoah to ensure his citizens washed their hands (and body) thoroughly and regularly

Boils: What would an infectious diseases consultant suggest?

• in the past 5 years we have experienced:• red tide from red algal blooms in N. American

waters• bedbugs in and around Toronto (and other cities

in N. America)• West Nile Virus from insect bites• widespread cattle disease (hoof-and-mouth in the

United Kingdom, “Mad Cow Disease” in Canada and elsewhere)

The Plagues: A modern perspective

• anthrax (with a bioterrorist outbreak in Florida and New York that was never solved)

• boils, with a current outbreak of MRSA (or methicillin-resistant Staph. aureus, a superbug)

• locust infestations in Africa, Australia, and parts of Middle East

• a blackout in Southern Ontario (and much of northeastern US)

• don’t need to remind the dramatic weather we have seen around the world, with hail, thunder, etc.

The Plagues: A modern perspective

•enforced appropriate public health and sanitation measures•recommended, where possible, vaccination against preventable diseases•encouraged separation of animals and humans•where indicated, would have prescribed antibiotics•would have urged him to “Let our people go!”

What would an Infectious Diseases Physician have done

to help Pharoah cope with the plagues?

what would an infectious diseases physician have … limmud-1.pdf• boils, with a current outbreak...

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