CADUCEUS - Volume 12 - Number 1 - Spring 1996

7/27/2019 CADUCEUS - Volume 12 - Number 1 - Spring 1996

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CADUCEUSA Humanities Journal for Medicineand the Health-Sciences

Historical and Contemporary Aspects ofCommunicable Disease Control

SPRING 1996 VOLUME 12 NUMBER 1


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CADUCEUSA Humanities journal for Medicine and the Health SciencesVolume 12 Number 1 Spring 1996

Contents2 Introduction: Historical and Contemporary

Aspects of Communicable Disease ControlPascal James Imperato, Guest Editor

7 An Epidemiologic Analysis of the TenPlagues of EgyptJohn S. Marr and Curtis D. Malloy

25 Cholera: Outlook for the Twenty-First CenturyJohn P. Craig

43 The Tuberculosis Story: From Koch tothe Year 2000Mahfouz H. Zaki and Mary E. Hibberd

61 Smallpox and Measles in Mali: ContrastingControl Strategies and OutcomesPascal James Imperato

COVER: Block of 1969 stamps issued by the Republic of Mali in honor of the smallpox vaccinationcampaign. The stamps are provided by Pascal J. Imperato, whose article begins on page 61 of this issue.

Copyright 1996 by the Board of Trustees of Southern Illinois University, ISSN No. 0882-7447

Published by the Department oiMedical HumanitiesSouthern Illinois UniversitySchool ot Medicine

EditorslohnS. Haller, |r IJitorPhillip V. Davis, Deputy EditorMary Ellen McEUigott,Managing t ditoiJean L. Kirchner, EditorialResearcher

Department of Medical HumanitiesI heodore K 1 eBlang, CluuM I vnne Cleverdon,Assistant to the Clmtr

Barbara Mason, Curator,The Pearson Museumlean I . Kirchner,Subscription Manager

Caduceus is produced for theDepartment of MedicalHumanities by the Division oiBiomedical Communications,Southern Illinois UniversitySchool of Medicine.Jim Hawker, CoordinatorLinda Clark Ragel. DesignerPatricia Baker, Typesetter


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An Introduction

Historical and ContemporaryAspects of Communicable DiseaseControlPascal James Imperato, Guest Editor

There is a renewed interest in communi-cable diseases in the United States as

we approach the close of the twentieth cen-tury. That interest may seem paradoxicalsince this is the century in which the majorcommunicable diseases were believed con-quered in this country through a combina-tion of improved living standards, sanitarymeasures, vaccines, and antibiotics. So dra-matic was the decline in morbidity and mor-tality from such major communicablediseases as polio, measles, and rubella, thatby the early 1970s the New York City De-partment of Health had difficulty recruitinga director for its Bureau of CommunicableDisease Control. 1 Yet this was the bureauthat only a few years before had investigatedmajor epidemics made famous by BertonRoueche in his book Eleven Blue Men. 2There were several reasons why commu-

nicable disease control had fallen to a lowerpriority in public health. Dramatic reduc-tions in the morbidity and mortality of thosediseases generated excessive confidence inthe abilities of vaccines and antibiotics aloneto control them. Other public health priori-

tiesincluding lead poisoning and the her-oin epidemicmoved to center stage andreceived significant levels of both federaland state funding. There was a failure torecognize that changing demographic pat-terns due to immigration from disease-en-demic Third World countries would soonintroduce large numbers of infected indi-viduals, as in the case of tuberculosis. Re-grettably, public policy makers andlegislators cut funding for immunizationprograms, failing to realize that inadequateaccess to them for poor inner-city and ruralchildren would create large pools of suscep-tibles capable of sustaining new epidemicsand outbreaks. Finally, there was little un-derstanding that social behaviors could startand sustain epidemics. The role of crack co-caine in generating the national syphilis epi-demic of the late 1980s and early 1990s is arecent example of the powerful influence ofa social determinant on disease morbidity.3

For most of the 1970s, public health de-partments in the United States providedsteady but back-burner support for commu-nicable disease control activities. The 1976

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outbreak of Legionnaires' disease in Phila-delphia caused some public health leaders torethink their spending priorities. Most, how-ever, viewed the Philadelphia and sub-sequent outbreaks of the disease as unusualevents that did not require a shift in resourceallocation. That complacency was reinforcedwhen the predicted 1976 Swine Flu epidemicdid not occur.4 Yet from a certain perspec-tive, the outbreaks of Legionnaires' diseaseof the 1970s and cases of toxic shock syn-drome in the early 1980s put public healthdepartments on alert to the reality that theycould no longer take communicable diseasecontrol for granted. Despite the disappear-ance of naturally transmitted smallpox in1977 and the development of more effectivevaccines and antibiotics, prescient publichealth specialists and scientists recognizedthat newer pathogens might emerge fromman's manipulation of his environment, andthat existing pathogens could soon prove tobe resistant to known prophylactic andtherapeutic agents.By the mid-1980s, after a lapse of almost

two decades, communicable disease controlunits were once again at the center of publichealth departments. This dramatic shift wasbrought about by the epidemic of acquiredimmunodeficiency syndrome (AIDS) in theearly 1980s. As federal and state fundingimproved, public health departments re-built their communicable disease control ca-pabilities around AIDS. Infections such astuberculosis and syphilis, which reappearedin epidemic form in the late 1980s, sustainedtheir strong commitment to communicabledisease control. Finally, emerging patho-gens, notably the Ebola virus, have demon-strated that the future of communicabledisease control contains many unknowns.The emerging pathogens of the 1990s have

caused a drastic change in how wenow view

REPUBUOUE DU MALIPOSTES E7 TELECOMMUNICATIONS

CAMPAGNE COMTPE LA VARIOLE ETLA WUCEOLE

PREMIER JOUR D EMISSIONTinge llmlte (numerate de 1 a 20031 (^0 1 3 8 5

This first-day cover for a 50 franc stamp, issued November 10, 1969,commemorated the smallpox eradication/measles control program in Mali.

communicable disease control. The exces-sive confidence of the 1970s has given wayto a greater realization of the complexities ofhuman/pathogen interactions. There hasalso been a commitment of resources. Thatunderstanding and commitment are fuelednot only by the insights of scientists but alsoby the concerns of the American public, whohave learned that these pathogens are oftenfatal, defying easy solution through the useof vaccines and drugs. They both fascinateand frighten, and often appear because wealter and disrupt the delicate balances be-tween them, us, and the environment weshare.5

World population growth has given riseto human encroachment on what were oncethe wild refuges ofmany pathogens. In thoseremote forested environments, viruses suchas Ebola have reached a state of equilibriumwith natural hosts over many millennia.Once transported from that balanced envi-ronment, the viruses cause lethal epidemicsas they enter a human population withwhich they have had little or no contact.Man is not only coming into contact with

new viruses but also transporting old ones

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I 1

The Ped-O-Jetautomatic jetinjector being usedto administermeasles vaccine,San, Mali, 1968

to different locations. We facilitate thespread of epidemics by manipulating ourindoor environments and the food we eat.Our excessive and often unnecessary use ofantibiotics has given rise to resistant strainsof bacteria. The result has been dramaticrises in deaths from pneumonia and septice-mia, often among hospitalized elderly pa-tients. In response to the growing threat ofinfectious diseases, the Journal of the Ameri-can Medical Association and thirty-five othermedical journals joined together on January16, 1996, in a concerted call for increasedefforts against these diseases.6 The editorssimultaneously published a total of 242 arti-cles on the subject to emphasize its impor-tance. One of the most sobering statistics toemerge from those studies is that, exclusiveof AIDS, infectious disease mortality rose by22 percent in the United States between 1980and 1992.7

If the first eight decades of the twentiethcentury were marked by continued successin the control of communicable diseases, thelast two decades have brought us to the so-bering frontier of emerging and reemerginginfections. We now recognize that we willhave to deal continuously with newer epi-demics due to our disruption of the environ-ment, as well as with older ones that emergebecause of social, technical, and behavioraldeterminants.

The essays in this issue of Caduceus dem-onstrate both the complexities of severalpathogens and the challenges inherent inattempts to control the epidemics theycause. In addition, John S. Marr and CurtisD. Malloy present a new and interesting uni-tarian hypothesis concerning the ten plaguesof ancient Egypt. They use a modernepidemiologic approach to analyze theseplagues, discuss previous scholarly conclu-sions, and use the entire corpus of availabledata to formulate their new hypothesis.Their conclusions will certainly not be thelast on this approximately 3,500-year-oldstory. They will however, stimulate furtherreflection and discussion, proving onceagain the wisdom of the ancient Greeks, whoobserved: "There is always something newout of Africa."8John P. Craig discusses the fascinating

story of the Seventh Cholera Pandemic,which began in 1961. His essay presents in-triguing details about the epidemiology,bacteriology, and immunology of the Vibriocholerae. He shows how recent advances inoral and intravenous fluid and electrolytereplacement therapy, as well as greater ex-pertise on the part of medical personnel,have reduced mortality to less than one per-cent. This is a remarkable twentieth-centuryaccomplishment for a disease that was onceinvariably fatal for half of those who con-tracted it. Yet, as Dr. Craig notes, cholera isprimarily controlled today not by vaccina-tion or by breaking the chain of transmissionbut by treating people after they have con-tracted it.

Tuberculosis, once known as the "whiteplague," was a major cause of morbidity andmortality in the United States in the earlypart of this century.9 It caused enormoussocial disruption and great economic hard-ships as families were broken up in the inter-

4 Historical and Contemporary Aspects


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ests of isolating victims in sanitoria. Isola-tion, rest, fresh air, and surgical procedureswere all that medicine had to offer in termsof treatment. A vast system of state-operatedsanitoria filled with tuberculosis patientswas in existence until the 1940s, when anti-tuberculosis drugs became widely available.Most of these specialized hospitals wereclosed by the 1960s and 1970s, vivid testi-mony to the assumed conquest of yet an-other communicable disease. 10 Yet was thedisease really controlled? As Mahfouz H.Zaki and Mary E. Hibberd describe in theiressay on tuberculosis, early assumptionsabout eradication were quickly provenwrong. As disease prevalence declined inthis country, however, federal funding fortuberculosis control programs was dramati-cally reduced. Such programs were given anincreasingly lower priority in local healthdepartments, based on the assumption thatthe disease was well under control. Duringthe 1980s, the incidence of tuberculosis sud-denly surged in the United States due toimported infections among recent immi-grants and AIDS-associated disease.As Drs. Zaki and Hibberd describe, there

are many newer and difficult challengesposed by this reemerged infection. Amongthem are multiple drug-resistant strains andthe growth of patient noncompliance withdrug treatment. Zaki and Hibberd detail theenormous financial costs of controlling theresurgent tuberculosis epidemic. They alsomake the cogent observation that relaxingcontrol measures and reducing funding fora disease whose incidence is declining is aserious public health policy error.The fourth essay in this issue contrasts the

control strategies and outcomes for small-pox and measles in the West African countryof Mali. A focused country study, it serves toillustrate a number of the issues and prob-

lems that confronted many of the othereighteen West and Central African countriesthat participated in a multiyear effort toeradicate smallpox and control measles.The eradication of smallpox stands as one

the great public health achievements of thetwentieth century. The success of the eradi-cation effort in West and Central Africa wasin large measure due to the dedication andexpertise of American personnel assigned toindividual countries. Backed by a commit-ted leadership staff at the Centers for DiseaseControl in Atlanta, these young physiciansand operations officers left for Africa full ofenthusiasm, hope, and even trepidation.Their determination had been galvanizedover a period of several months in Atlanta,where they were trained not only to diag-nose smallpox and investigate epidemicsbut also to speak French and repair the en-gines of Dodge trucks.The field staff of courageous young

Americans was fortunate in having an expe-rienced and accomplished physician as theirleader. George Ignatius Lvthcott never wa-vered in his belief that smallpox could beeradicated. As regional director for the Westand Central African Smallpox Eradica-tion/Measles Control Program, he continu-ously pursued that goal. More important, heprovided his staff with the encouragement,support, and counsel needed to overcomeenormous odds. In so doing, he helped cre-ate the ultimate triumph of eradicating adisease. 11The closing vears of the twentieth century

are a fitting time to examine different aspectsof communicable disease control. For this isthe century in which historic advances tookplace in the prevention, control, and treat-ment of man\ - diseases. Antibiotics were de-veloped and have saved millions of lives.Effective vaccines for preventing the killer

Pascal James Imperato 5


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lives. Effective vaccines for preventing thekiller diseases of childhood have allowedyoungsters all over the world to reach adult-hood. Improved living standards and sani-tation have helped to interrupt diseasetransmission, and science has found themeans to treat even viruses.

This is also the century, however, in whichwe came to realize that combinations of so-cial, technical, and behavioral determinantsgreatly influence the life histories ofcommu-nicable diseases. Emerging and reemergingepidemicsas well as antibiotic resis-tancehave their origins in human actions.Both scientists and the publicnow know thatfuture successes against these diseases willnot be achieved through a reliance on drugsand vaccines alone. The essays in this issueof Caditcens address some of these issues,and bring the lessons of history to bear uponpresent and future efforts at communicabledisease control.

Notes1. Pascal James Imperato, Medical Detective(New York: Richard Marek Publishers, 1979), 163-

64.2. Berton Roueche, Elei'en Blue Men and Other

Narratives of Medical Detection (Boston: Little Brown& Co., 1953).3. R. T. Rolfs and G. P. Schmid, "The United

States syphilis epidemic: Reason for optimism (atleast for the moment)," New York State journal ofMedicirie 91 (1991): 522-23.

4. Richard E. Neustadt and Harvey V. Fineberg,The Swine Flu Affair. Decision-Making on a SlipperyDisease (Washington, D.C.: U.S. Department ofHealth, Education, and Welfare, 1978).

5. Emerging pathogens currently attract muchpopular attention. They have been the subject ofpopular books (e.g., Laurie Garrett, The ComingPlague: Newly Emerging Diseases in a World out ofBalance [New York: Farrar, Straus and Giroux,

1994]), a Hollywood film ("Outbreak"), front-pagenews stories, and prime-time television coverage.6. D. A. Goldmann, R. A. Weinstein, R. P. Wen-zel, et al., "Consensus Statement: Strategies to Pre-vent and Control the Emergence and Spread ofAntimicrobial-resistant Micro-organisms in Hospi-tals: A Challenge to Hospital Leadership," JAMA275 (1996): 234-40; J. A. Patz, P. R. Epstein, T. A.Burke, et al. "Global Climate Change and EmergingInfectious Diseases," JAMA 275 (1996): 217-23; J.Lederberg, "Infection Emergent," JAMA 275 (1996):243-45; M A. Winker and A. Flanagin, "InfectiousDiseases: A Global Approach to a Global Problem,"JAMA 275 (1996): 245-46.

7. "Doctors Tell of International Resurgence ina Variety of Infectious Diseases," Neiv York Times,Jan. 17, 1966, A16; R. W. Pinner, S. M. Teutsch, L.Simonsen, et al., "Trends in Infectious Diseases Mor-tality in the United States," JAMA 275 (1996): 189-93.

8. Pliny the Elder (23-79), a Roman scholar,popularized the Greek proverb in Latin as "Ex Af-rica semper aliquid novi."

9. R. J. Dubos, "Biologic and EpidemiologicalAspects of Tuberculosis," American Revieiv of Tuber-culosis 68 (1953): 1-8.10. K. W. Wright, J. Monroe, and F. Beck, "AHistory of the Ray Brook State Tuberculosis Hospi-tal," New York State Journal of Medicine 90 (1990):406-13.

11. Lythcott later became associate dean for ur-ban and community affairs at the ColumbiaUniversity College of Physicians and Surgeons, as-sociate vice-chancellor for academic affairs at theUniversity of Wisconsin, and in 1977 was appointedby President Jimmy Carter as administrator of thehealth services administration in the Department ofHealth and Human Services. He then served as deanof the City University of New York's Sophie DavisSchool of Biomedical Education, and later as assis-tant commissioner in the New York City Depart-ment of Health. He died at his home on Martha'sVineyard on Oct. 7, 1995. See Wolfgang Saxon,"George Lythcott, 77, Pediatrician, Dean and HealthOfficial," New York Times, Oct. 11, 1995, B8.

ACKNOWLEDGMENTSThanks are extended to Florence Kavaler, M.D., for herhelpful suggestions and to Lois Hahn for her carefulpreparation of the typescript.

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An Epidemiologic Analysis of theTen Plagues of EgyptJohn S. Marr and Curtis D. Malloy

The Ten Plagues of Egypt described inthe Book of Exodus are the first exam-

ple in a historical written record of whattoday might be described as "emerging in-fections." Causes and interpretations of theTen Plagues have fascinated theologians,historians, Egyptologists, musical compos-ers, scientists, and physicians for centuries.More recently other health professionals invarious disciplinesincluding epidemiol-ogy, epizootiology, entomology, microbiol-ogy, and toxicologyhave postulatedprobable causes for one or more of theplagues. In recent years reinterpretations ofancient texts and new information about en-vironmental factors and disease causationhave allowed unique interpretations of thatseries of early public health catastrophes.Yet despite centuries of study, fundamentalquestions remain.Were the Ten Plagues historical events, or

perhaps only a collection of religious arche-typal stories or myths? If the plagues didoccur, why were there no specific citationsto them in ancient Egyptian literature? IfEgyptological research suggests some sem-blance of their occurrence, who might best"fit" as the candidate for pharaoh presidingover the plagues' occurrence? If a specificpharaoh can be posited (and satisfactorilyreconciled within the more accepted talmu-dic and biblical chronological timeframes),

when and where in time and place (theologi-cal and Egyptological) would the plaguesunder his reign and the ensuing Exodushave occurred? After those questions havebeen addressed, one is in a better position tooffer a scientific interpretation to these ques-tions: What were the causes of each of theTen Plagues? How did they occur?This paper will attempt to integrate biblical,historical, and Egyptological data to support alogical conjecture for the specific time, place,and pharaoh. Our conclusions follow the tra-ditional tenets of epidemiologic investigation,the first of which is to answer the question,"Was there an epidemic?" That will be fol-lowed by corollary questions of when, where,and who might have been affectedthe time-place-person questions of descriptiveepidemiology. We then address specific ex-planations for each of the Ten Plagues, at-tempting to answer the "how" and "why" ofanalytical epidemiology.

Previous authors have postulated manyexplanations of the plaguestheological,supernatural, quasi-scientific, and scientific.We will address those extensive and goodworks, using Occam's razor as needed toreduce discordant explanations to the sim-plest and most logical. We then propose thatthe first nine plagues built upon each of thepreceding plagues, and precipitated the final,most devastating plague, which culminated

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in finally having the pharaoh agree toMoses' demand to "let my people go" (Exo-dus 5:1). 2

Did the Ten Plagues Occur?The epidemiologic analogue to the above

question is "Was there an epidemic?" If theanswer is no, the investigation is terminated.There is some evidence, however, separatefrom the original talmudic and biblical ac-counts, that the plagues did occur. Im-manuel Velikovsky has cited passages fromthe Admonitions of Ipuzver (as translated in1909 by Sir Alan H. Gardner), an ancientEgyptian papyrus, which substantiates thata series of catastrophes did occur at the endof the Middle Kingdom. 3 One of the earliestand most complete analysis of possiblecauses of the plagues was offered by GretaHort, who based her theory on passagesfrom the papyrus. 4

Who, Where, and When?There is little if any secular information to

substantiate the historicity of the Exodusaccount. Some Egyptologists consider theBible as story, not as history, noting that halfa millennium or more had passed betweenthe time of those events and the time of thefirst known written Hebrew literature. Astrictly historical analysis would reveal thatif the plagues and the Exodus did occur, theymust have transpired before 1200 B.C.E.,when the so-called "Israel" stela of the Phar-aoh Merneptah described a peoplenot acountrycalled "Israel" that had alreadyreached Canaan.Furthermore, some have criticized utiliz-

ing the Ipuwer papyrus to substantiate theExodus account, stating Ipuwer simply pro-vides a contrast to the transition from a pre-

viously chaotic environment to the sub-sequent reign of a just and capable ruler.Many scholars who believe that the

plagues actually occurred nevertheless dis-agree on the identity of the reigning pharaoh(and therefore on the likely years). Hortwisely ignores the question. Donovan A.Courville, after considerable debate, wasunable to make a determination. Citing firstcentury AD. Jewish theologian Josephus asan authority, Cecil B. DeMille chose Ra-messes II for his cinematic rendition TJie TenCommandments. In 1981 Biblical scholarWerner Keller also reasoned that RamessesII was the pharaoh. H. M. D. Hoyte, on theother hand, citingJohn J. Bimson, concludedin 1993 that the pharaoh was Thutmose III.Velikovsky appears to concur with Hort,although his candidate is not specified. Heidentifies a "Taui Thorn the last king of theMiddle Kingdom. He is the Tau Timaeus(Tutimaeus of Manetho)." Egyptologists to-day prefer the spelling of Thutmose for thevarious New Kingdom, 18th Dynasty rulers.Independent of various spellings, however,all four Thutmoses (I-IV) reigned well afterthe Hyksos, who were posited by Veli-kovsky. 5A definitive identification of the pharaohis of some interest since the two (or more)postulated pharaohs span different time pe-riods, varying slightly, depending on thesource of dating: Ramesses II (1290-1224B.C.E.); Thutmose I (1504-1492 B.C.E.); Thut-mose II (1492-1479 B.C.E.); Thutmose III(1479-1425 B.C.E.); and Thutmose IV (1401-1391 B.C.E.). For Velikovsky that is of greaterimportance, as he ties the plagues and fierypillar and parting of the Red Sea to othercontemporary Old and New World histori-cal accounts. His overall explanation is a

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series of major climatological disasters pre-cipitated by a comet and coinciding with theHyksos invasion. Unfortunately, the Hyk-sos period (1640-1532 B.C.E.) does not coin-cide with any of the four Thutmoses. 6Hoyte suggested that the Ten Plagues

took place under Thutmose III (1479-1425B.C.E.) over an eleven-month span, begin-ning in July-August and lasting throughApril-May of the following year. Neitherthe two pharaohs suggested by most schol-arsThutmose III or Ramesses IInor theduration of ten months within which thoseplagues may have taken place, are incom-patible with the selected notations of theIpuwer papyrus.

Scholars do agree that the ancient city ofMemphis (today, Mit Rahina), located at themouth of the Nile delta, was the residence oflate Middle Kingdom and early New King-dom pharaohs. A consensus supports thatthe land of Goshen was somewhere north-east of Memphis, near the ancient (now lost)city of Heliopolis, a few miles north of pre-sent-day Cairo. Heliopolis was referred to inthe Bible as "On, Aven, and Beth-Shemesh."Hort proposed that Goshen lay some fiftymiles northeast of Heliopolis, in the WadiTumilat near present-day Tell el-Maskhuta,a river valley that once connected the Nile tothe northern extension of the Red Sea. IfGoshen existed today, it would be aboutfifty miles northeast of present-day Cairo,less than one hundred miles from what istoday known as the Gaza strip. The Red Seais viewed by most historians as a mistrans-lation of the reed sea, a marshy extension ofwater extending from the Red Sea towardsouthwest Gaza. Indeed, a fast, primarilyeasterly exit from Memphis (29.8"), throughHeliopolis (30.1) and Goshen (Wadi Tumi-lat, 30.8") would be well above the north-ernmost extension of the Red Sea (30.0'). 7

Interpretations of the Ten Plagues of EgyptInterpretations of what the Ten Plagues

might have been can be grouped into twocategories: theological and scientific. Theformer group explores not only alternativetranslations of the original Hebrew and Ara-maic texts but also secondary biblical inter-pretations. Scientific writers offerexplanations for either a specific plague, aselected subset of plagues, or all ten of them.They further propose either separate expla-nations for each plague or procrustean theo-ries to identify a single common factor orcondition. We have chosen to discuss theplagues in pairings of successive twos,which we believe is the simplest way ofdiscussing and building toward a logicaland unified conclusion for the final, devas-tating plague. 8 For a summary of all inter-pretations, see pages 12-13.

First and Second PlaguesFresh Waters Turn toBlood and Frogs

Prior to the germ theory, the only expla-nation posited for the cause of the firstplague was an unknown noncontagionist

Seal of Thutmose III

(Reproduced withpermission fromJohn Barnes andJaromir Malek,Atlas of AncientEgypt [New York:Facts on File, 19891)


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theory of "contamination" that could causean extensive fish kill. After the advent of thegerm theory, more specific infectious andnoninfectious causes have been postulated.Silt remained an early candidate as the causeof a reddish Nile; later, that explanation wasrefined to a specific silt known as "marl,"originating from Ethiopia and carried by acresting Blue Nile. Velikovsky's more recentproposal was that cometary red dust causedthe Nile to turn color.9

Recent explanations for the red-coloredwaters have favored protozoan, zooplank-ton, dinoflagellates,and both salt- and fresh-water algal (phytoplankton) blooms. All ofthose bloomsplant, fungal, or proto-zoandeoxygenate water and producenoxious toxins for both fish and frogs. With-out predator fish, frogs could initially breedfreely in both ponds and the Nile; in timethey would overpopulate the river, eventu-ally escaping the anoxic, toxic, and putrefy-ing environment by migrating to land, henceto die and decompose along with the fish.The Nile and adjacent land would thus be-come fouled, and the waters dangerous todrink or bathe in.

P. A. Tester, citing the Exodus account,noted that while fewer than fifty out of ap-proximately five thousand known phyto-plankton species are toxic, those that possesstoxins can be dangerous to aquatic life. E. C.D. Todd, referring to historic and prehistoricdata, cites nearly two dozen examples ofspecific phytoplanktons causing variousoutbreaks throughout the world. Wayne W.Carmichael listed diseases associated withfreshwater blue-green algae. JoAnn M.Burkholder described the dinoflagellate Pfi-esterin piscimorte, which was found in estuarywaters and, as the species name implies, wascapable of killing fish. Neither an unstatedcontamination, cometary dust, nor silt

would by itself explain all of the phenomenadescribed above. In addition, the Nile, itstributary waters, well water, and other bod-ies of standing water were fresh. Most of theabove-mentioned aquatic, phytotoxicblooms occur in salt or brackish water, withthe exception of the recent discovery offreshwater blooms. 10We conclude that a freshwater dinoflagel-late biomass bloom, as described by Car-michael and Burkholder, was responsiblefor the change in the color of the Nile, thedeath of fish, and the subsequent populationexplosion among frogs.The death of fish"an important source

of protein and minerals" for the ancientEgyptian, was more than an inconvenience.It was the first of many nutritional compro-mises caused by ensuing plagues to be in-flicted on the Egyptian Empire, culminatingin the last plague. The eventual death offrogs also removed an important healthagent, for frogs were the natural enemy ofcertain biting insects that were otherwisefree to multiply unhindered. 11

Third and Fourth PlaguesLice and the Swarmof FliesThe first mention of two of the three mem-

bers of the Class Insecta (Hexapoda) is ofparticular interest to entomologists (the sec-ond mention occurs with the locusts of theseventh plague). Richard L. Brown hasnoted that any identification of an insect byeither order or genus in the Book of Exoduspredates the first taxonomic attempts byAristotle to classify insects (or arthropods)by nearly one thousand years. Thus, anyarthropod may be considered a putativevector, including the members of the ClassArachnidasoft ticks, hard ticks, scorpions,spiders, and mites. All such arthropodsabounded in Egypt.12



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The original Hebraic term for "lice" ismost often translated as "vermin." Thatterm, as such, is commonly construed as anarthropod skin infestation, not as flying in-sects. The term also implies that the multipleoffenders could be visibly recognized. Thus,the otherwise ingenious conclusion by J.Korzets that the cause of the third plague"itch" was due to the microscopic scabiesmite (Sarcoptes scabiei) is probably incorrect,although David J. Sencer notes that thechronic allergic sequela of that infestation,"beggars' itch," is an alternative explana-tion. Of the three human body lice knowntoday (Pediculus corporis humanis, P. capitishumanis, and Pthirus pubis), none fulfill thedescription of the macroscopic infestation"on man and beast," since those lousy can-didates are species-specific, and do not in-fest nonhuman hosts, as the text clearlystates. 13

Alternative explanations are such indis-criminate biters as the soft tick (Orthinodorismoubati), hard tick (Boophilus annulatus), andmaggot infestation or myiasis (e.g., Dermato-bia hominis) found in North Africa. Althoughentomologically correct for Egypt, all ofthose dermatological infestations are toomacroscopic to warrant usage of the term"vermin." And, like lice, none have the ca-pability of flying.Of flying insects resident in Egypt, recent

findings that Simulian species of blackfliestransmitting onchocerciasis (river blind-ness) in many areas of eastern Africa (includ-ing the Sudan) offers another explanation. Thedermatosis caused by those flies is singularlycharacterized by intense itching. Even ifblackflies were candidates for the "lice,"however, the vector is too large and recog-nizable to be called vermin, and the pruritusinduced by an allergic reaction to the death

of O. volvulus microfilaria takes months oryears to appear.Hoyte suggests an alternative to the He-

braic translation of "chinnim"the Greek"sciniphes," or -mosquito/gnat. More thanforty species of mosquito capable of trans-mitting disease have been cataloged inEgypt; the most abundant genera of mos-quito, in decreasing order, are Anopheles,Culex, Aedes, Culiseta, and Uranotaenia. Mos-quitoes are relatively large and easily recog-nized. Nevertheless, Hoyte preferred themosquito Culex antennatus as the most likelyexplanation for "lice." By so doing, he dis-missed the midge and sandfly as both thecause of the infestation and as a possiblevector for subsequent plagues. 14The midge, a lay term that includes Culi-

coides species (also known as gnats, "no-see-ums" and "punkies") are nematocerous flieswhose larvae and pupae live in moist soil.They are small and bloodsucking, thus bet-ter fulfilling the near-microscopic descrip-tion of "lice"; furthermore, they may appearto originate in "dust" because their pupaedevelop and eventually fly out from whatwould appear as dirt or dust. The same is truefor sand flies (Phlebotomus species). Eightspecies of Culicoides and seven species ofPhlebotomus have recently been identified inEgvpt. The latter is a vector of sandfly feverand leishmaniasis (visceral and cutaneous).Those two zoonoses are unlikely to be con-fused with either the fifth or sixth plagues. 15

Unlike the sand fly, which lays it eggs incracks in walls or stone outcroppings, Culi-coides larvae feed on abundant microorgan-isms in decomposing detritus, such as theremains of fish and frogs. The eventual ex-plosive emergence of adult flies might bewell construed as a plague coming from "allthe dust of the land."


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Summary of Interpretations Given to the Ten Plagues of EgyptPlague

ARAMAICHEBREW

Biblical Passage

Chapter, Verse

Ipuwer Papyrus

InterpretationBryantEngland/1810BlancUnited States/1890VelikovskyUSSR/1950HortNetherlands/1957SchoentalUnited States/1980SchmidtGermany/1990

JacobyUnited States/1990HoyteAustralia/1993CeccarelliItaly/1 994Marr, MalloyUnited States/1996

1. Water to Blood 2. Swarm of Frogs 3. Plague of Lice 4. Swarms of FliesDAM TSTAR-DEI-A KI-NIM A-ROVBr srnas o' any

"Stretch out thine hand uponthe waters of Egypt: upontheir streams, upon their riv-ers, upon their ponds, upontheir pools of water, that theymay become blood."

Exodus 7:19

"Lo, the river is blood, Asone drinks of it one shrinksfrom the people. And thirststor water."

"tainted andpolluted streams"

"Stretch forth thine hand withthy rod over the streams,over the nvers, and over theponds, and cause frogs tocome up upon the land ofEgypt."

Exodus 8:5

"Aaron stretched out hishand with his rod, and smotethe dust of the earth, and itbecame lice in man, and inthe beast; all the dust of theland became lice, throughthe land of Egypt."

Exodus 8:16

"fnhere came a gnevousswarm of flies intothe houseof the Pharaoh, and into hisservants' houses, and intoall of the land of Egypt; theland was corrupted byreason ofthe swarm of flies."

Exodus 8:24

"Towns are ravaged, UpperEgypt became wasteland.Lo, crocodiles gorgeon theircatch.'f

Frogs (a diety) and theirdeath are emblematic of aprophetic influence

Anthrax(Bacillus anthracis),

infected and killed frogs.

Lice: "vermin . . . pediculi" (House?) fliesrepresenting "Zebub"

Flies transmitting anthrax Flies transmitting anthrax

The fall of red meteoritedust from a comet polluting

watersRed silt, flagellated protozoa

Euglena sanguina,Haematococcus pluvialis

Microfungi andFusanum roseum

contaminating waters

Waters contaminatedby dead fish

Nile (a diety) waters madeundnnkable

secondary to dead fishDinoflagellates

Gymnodtuium and Glenodintum(unnamed species)

DinoflagellatesGymnodiuium and Glenodinium

species (after Hoyte)Freshwater cyanobacteriacausing river to turn red,

and killing fish

Anthrax(Bacillus anthracis),

infected and killed frogs.Frogs killed by

dinoflagellates producingsoluble poisons

Frogs

MosquitOS(Culex species)

"vermin"

Frogs

Dehydration anddesiccation killed escaping

frogs

Frogs

Frogs leave deoxygen-ated waters and die,

contributing to Plague 3

"Sand fleas," not gnats

"Midges"(Culex antennatus)

"Midges"Culex antennatus

(after Hoyte)

CuScoides appear de novo frompupae hatching in sand (Hoyte)

transmitting Plague 5

Stable flies(Stomoxys calcitrans)

transmitting Plagues 5 & 6

Horseflies

"An insect akin to a wingedant"Stable flies

Stomoxys calcitrans(see Hort)

Streptococcal andStaphylococcal infections;

Babesiosis

Stable flies(Hort and Hoyte)

transmitting Plague 6f Some rabbinical scholars have interpreted the Hebraic text as possibly meaning amphibians in general.



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5. Animal Murrain 6. Boils and BlainsDE-VER SH'HINnan *"rw

"Behold the hand ol the Lordis upon thy cattle which is inthe field, upon the horses,upon the asses, upon thecamels, upon the oxen, andupon the sheep; there willbe a gnevous murrain."

Exodus 9:3

to, all beasts, their headsshall weep. Cattle bemoanthe state of the land."

"the distemper"

Anthrax

Secondary skininfections from comet

dusts

Anthrax

Mycotoxms

Surra (debab)( Trypanasoma evansi)

Babesiosis(Babesia bigemini)

African horse sickness;Bfuetongue; Epizootichemorrhaghic disease

Take to you handfuls of ashesot the furnace, and let Mosessprinkle it toward the heavenin the sight of fhe Pharaoh.And it shall become small dustin all the land of Egypt, andshall be a boil breaking forthwith blams upon man. and uponbeast, throughout all the landof Egypt."

Exodus 9:8

"Plague is throughout theland. Blood is everywhere."

Thai where any atom ol this dustbe whiffed might be entailed, butwith a different intention . aplague and a curse."

Anthrax

Boils secondary todusts, blisters from flaming

naptha

Anthrax

2 bacterial infect, due toimmunosuppression by

tnchothecenes

"herpes-like infection"''"bubonic infection*?

"Intlamation of sexual organs"7

Ecthyma(Group A hemoloytic

Streptococcus pyogenes)

Babesiosis(Babesia bigemini)

Glanders (fancy)Pseudomonas mallei

7. HailstormsBA-RADTO

"Stretch forth thine hand to-ward heaven, that there willbe hail in all the land of Egypt,upon man and upon beast,and upon every herb of thefield, throughout the land ofEgypt.

Exodus 9:22

"Lo, hearts are violent,storms sweep the land."

"thunder, hail, fire"destroy crops

Hail

Dust, gravel, andburning napthafrom a comet

Hailstorms destroyedflax and bartey butnot wheat or spelt

Hail

Hail

8. LocustsAR-BEHnans

"[W]hen it was morning, theeast wind brought the lo-custs. And the locusts wentup over all the lands of Egypt,and rested in all the coastsof Egypt: very gnevous werethey; beforethem there wereno such they, neither afterthem shall be such."

Exodus 10:13

"Birds find neither fruit norherbs. . . .Trees are de-stroyed. No fruit nor hemsare found."

Locusts caused famines

Locusts

Locusts

Crops ruined by hailstorms

Hail

Halt destroyingestablished crops anddampening stored foods

Locusts ruined crops

9. DarknessHOSHEKH

"Moses stretched forth hishand toward heaven; andthere was a thick darknessin all the land of Egypt threedays: They saw not one an-other, neither rose from anyof his place tor three daysbut all the Children of Israelhad light in their dwellings "

Exodus 10:22

"Lo, the desert claims theland. . . . Those who hadshelter are in the dark of thestorm. . . Egypt will not begiven over (to] sand.. . . Theland is not light."

"a preternatural state ofnight"

Locusts swarms

Cinder dust froma comet

Sandstorms (khamsin)

Darkness 9

Sandstorms

10. Death of EldestMA-KATB'KHO-ROTnmsa nsa"About midnight I will go outinto the midst of Egypt: Andall the first-bom in the landof Egypt shall die, from thefirstborn of Pharaoh thatsitteth upon his throne, evenunto the firstborn of the maid-servant that is nehmd themill; and all the firstborn ofthe beasts '

Exodus 11:4

"Ladies suffer like maidser-vants. . . . Then he who wouldhave smitten the evil, stretchedout his arm agajnst it, wouldhave destroyed their seed andtheir heirs."

Confluence of God's will

Anthrax

An earthquakeFamine secondary to

destruction of wheat andspett harvests

Mycotoxm-induced deathfrom moldy feeds

Typhokt fever andsalmonelloses

(S. TyphV and entenditrs)

Schistocerca gregaria eat allremaining vegetation, including

sprouts and seedlings

Sandstorms (khamsin)cover existing food standsand stored food supplies

Mycotoxins specific tostored grains preferentiallykilled first to access store


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Unlike such bloodsucking insects as lice,those tiny, annoying hematophagous fliesare not species-specific; they bite both hu-mans and animals with a vengeance, as sug-gested by one species name, C. vexans. Bitescan cause severe local reactions, intense itch-ing, and weal formation. Until the late 1960s,Culicoides were considered "nuisance" ar-thropods, incapable of transmitting infec-tious agents. They are now recognized asbiological vectors of a number ofhuman andanimal viral diseases. Thus we conclude thatCulicoides was the cause of the third plagueas well as the biological vector for the fifthplague.16The fourth plague, the "swarm of flies,"

has been given numerous interpretations.Sometimes referred to as "beasts," theyshould be distinguished from the thirdplague, although some renditions of theplague account combine those two insects.Hoyte notes that the life cycle and bionomicsof the stable fly (Stomoxys calcitrans, L.) coin-cides with the ebbing of the Nile in Septem-ber, when abundant rotting vegetationfosters ideal harborage for its emerging lar-vae. Charles Brues listed thirty-one speciesof Stomoxydinae, including S. sexvittataRoubaud (now S. bilneata Grueriberg). In addi-tion, Stomoxys nigra Macquart occursthroughout Africa and attacks cattle, horses,and people. 17

Alternative explanations of the "swarm"have been the housefly (Musca), tsetse fly(Glossina), horsefly (Tabanus), and blackfly(Simulium). The housefly does not bite. Theother three are biters and bloodsuckers, ca-pable of causing severe pain, local irritation,inflammation, and itching. In only two of thefly genera, Glossina and Stomoxys species, doboth the male and female take blood meals.Bites ofboth flies necessitate ripping of flesh,often leaving open puncture wounds, lead-

Ancient Egyptian pictograph of a stablefly

(Reproduced with permission from John Baines andJaromir Malek, Atlas of Ancient Egypt [New York:Facts on File, 1989])

ing to secondary infections. Unlike the an-noying sand fly, the intensity and severity ofswarms of both tsetse and stable flies havebeen reported to induce anemia in pennedcattle and stampedes in wild animals. All ofthe aforementioned flies are capable oftransmitting infectious agents (vide infra),but only Glossina and Stomoxys appear to beappropriate insect vectors for either one orboth of the subsequent two plagues. We con-clude that the stable fly better fulfills the roleas the cause of the fourth plague.The sequelae of the first and second

plagues appear to have generated opportu-nity for plagues three and four. Denied po-table water or water in which to bathe, theEgyptians and their livestock would bemore exposed to infestation, attack, and sec-ondary infections. Either mechanically or



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biologically, at least one kind of fly inocu-lated pathogenic viral, bacterial, or proto-zoan organisms into animals and humans,causing subsequent disease. Thus, the thirdand fourth plagues might be logically linkedto the fifth and even the sixth plague.

Fifth and Sixth PlaguesMurrain in Animals andBoils and BlainsThe fifth plague is probably the first writ-

ten record of a true epizootica disease in-flicted upon animals but not humans. Aproper proposal should account for suchselectivity, as should the subsequent sixthplague, a zoonosis, which affected both ani-mals and humans. Specifically, the fifthplague struck many hoofed animalshorses, donkeys, camels, cattle (includingoxen), and sheep. Hoyte notes that the omis-sion of goats and pigs "is of social, notepidemiologic significance."

Nevertheless, that those animals, whichwere ofcommon occurrence in Egypt at thattime, were not mentioned is relevant, pro-viding negative evidence-clues as to whatthe plague may have been. The fifth plague,or "murrain," appears to be specific for cer-tain hoofed mammals, sparing domesticpets and wild carnivores, as well as birds,amphibians, and reptiles. In addition to fivecandidate diseases proposed by previousauthors, we propose five other lesserknown, arthropod-borne African epizooticsinfecting hoofed mammals. 18Anthrax is a severe bacterial infection ca-

pable of being transmitted by various directand indirect methods, including mechanicaltransmission by biting flies. Anthrax can in-fect a wide range of animals, especiallygoats. Wild animals, including elephants,hippopotami, and impala (but not frogs, assuggested by Hort) can also be infected withanthrax. Those animals, as well as goats and

pigs, are not listed or noted in the otherwisecomplete list of animals affected. Anthraxcan also cause human disease; its cutaneousform is associated with a 5-20 percent rateof human mortality, an observation that pre-sumably would have been recorded had itoccurred. Anthrax, we believe, is not a viablecandidate for the fifth plague. 19

Rift Valley fever, a viral disease transmit-ted by various genera of mosquitoes, alsocan cause illness in humans and may besimilarly dismissed. Rift Valley fever causesillness in goats and pigs but spares horses(prominently mentioned as being afflicted).Rinderpest and foot-and-mouth disease areairborne viral infections, but neither affectshorses. Two hard tick-borne rickettsial dis-eases, East Coast fever (Theiliasis) and heart-water (Coivdriosis) cause illness in cattle butnot horses; the former does not cause illnessin sheep, and the latter causes disease ingoats. Another hard tick-borne disease, ba-besiosis, is a protozoan disease mimickingmalaria and is capable of causing disease inall animals listed. As noted by Hoyte, eachequid and ruminant has a different and spe-cific genus of tick vector; moreover, the tickvectors are large, easily recognized duringattachment, and likely to have been noted.20

Surra, as proposed by Hoyte, is a proto-zoan disease caused by a trypanosome (T.brucei evansi). While responsible for diseaselimited to equids and ruminants, surra ismechanically transmitted by both tsetse andstable fly bites. Tsetse fly distribution doesnot extend into northern Egypt, however,and while stable flies are cosmopolitan, thedisease's present enzootic range in Africasuggests that it has never penetrated morethan 15 north of the equator.The last two diseases, African horse sick-

ness and bluetongue, are caused by virusesbelonging to seventeen different serological


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subgroups in the genus Orbivirus. Those twoRNA viral diseases are biologically trans-mitted by the same genus, the Culicoidesmidge. African horse sickness is extremelylethal in horses, donkeys, mules and otherequines, with a case fatality rate of 95 per-cent, but it spares other hoofed animals.Bluetongue is variably fatal for cattle, sheep,and goats but not for horses or pigs. Neitherdisease causes illness in humans, and theyare therefore logical choices for the murrainin animals. We therefore propose that thosetwo midge-borne diseases were the cause ofthe grievous fifth plague among hoofed ani-mals, including goats in the "flock" but notswine. Even though that may be an excep-tion to a unitary explanation, both epizooticsbest explain the selectivity of animaldeaths.21Thus, the earlier plague of lice (Culicoides

midges) also transmitted two arboviral dis-eases to hoofed animals. After introduction,disease spread from infected animals to oth-ers by many other biting insects, both me-chanically and biologically. Over a period ofweeks all susceptible animals would havebecome infected. Only herds and flocks ofanimals outside the distribution range ofCulicoides (a notoriously weak flying vector)were spared from those epizooticsi.e., theland of Goshen.The sixth plague, consisting of boils and

blains, struck both humans and "beasts.""Beasts," while not defined, is a truezoonosis that may or may not include someor all domestic and wild animals. Re-searchers have offered various explanationsfor that epidemic/epizootic. Blanc's andHort's proposals of ulcero-glandular an-thrax has been alluded to previously as be-ing transmitted by various flies. Hoyte alsosuggested that stable flies might transmitcombined staphylococcal-streptococcal in-

fectionsspecified as "ecthyma"to bothanimals and humans. Giovanni Ceccarelliproposed a variety of strains of babesia asthe cause. The latter appears less likely for anumber of reasons. The variety of vector-specific ticks that would be needed for mul-tiple-species transmission seems unlikely,and the disease presentations in man andanimals have no dermatological symptoma-tology. Regina Schoental, on the other hand,argues that a transient immunosuppressiondue to unnamed mycotoxins caused variouspathogenic and opportunistic bacterial skininfections as the putative disease and latersequelae.22The disease must have caused severe,

suppurative skin infection. Both anthraxand a combined staphylococcal-streptococ-cal infection fulfill that condition. Both canbe transmitted by flies, direct contact, orcontaminated food and milk. Spores of an-thrax may also be airborne, causing a sepa-rate, clinical presentationmediastinitis. Acombined staphylococcal-streptococcal in-fection is not considered transmitted by theairborne route. A more viable bacterial can-didate not previously considered is glanders(Pseudomonas mallei, farcy), a highly conta-gious, airborne zoonotic bacterial diseasetransmitted by direct contact or through flybites. First described by Aristotle in 330B.C.E., glanders is presently found through-out the Middle East and Africa. It is primar-ily a respiratory infection of horses,donkeys, mules, and goats (cattle are resis-tant to infection), with lymphatic and metas-tatic spread to other organs, including theskin or hide. Cutaneous manifestations inequids consist of "cord-like thickening ofsubcutaneous lymphatics along which aredistributed chains of nodules, some ofwhich are ulcerated." Human disease con-sist of "nodular eruptions on the face, legs,



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arms, involvement of the nasal mucosa andlater pyemia and metastatic pneumonia."21Whatever the sixth plaguein our opin-

ion, most likely glandersor the mode bywhich it was primarily spreadmost likelyairborne it may have been further propa-gated by the ingestion of tainted meat. Themajor consequence of the plague was fur-ther reduction of the protein supply (meatand milk), which had already been danger-ously reduced by a fish kill. Again, the He-brews' animals living in Goshen werespared both the fifth plague (African horsesickness and bluetongue) and sixth plague(glanders).

The Seventh and Eighth PlaguesHail andLocusts

Hail occurs throughout the temperate andtropical worlds, usually seasonally. Causedby collisions of supercooled water in cumu-lonimbus clouds, hailstones may have a di-ameter of 2mm to 13cm (1/1 6th inch to fiveinches). Larger hailstoneshave killed unpro-tected humans and animals; smaller stonescan still cause severe damage and destruc-tion to smaller animals and to crops. The haildescribed in the biblical account would havebeen certainly severe enough to kill or maimboth humans and animals caught in thefields. More important, the hailstormswould have devastated the seasonal fruit,vegetable, and grain crops of the Egyptiansat a time when they depended on their yieldto last through the following year. That wasthe antepenultimate assault on the Egyp-tians' existing food supply, which would befurther tested by the eighth plague, whenceEgyptians would have to rely on their mea-ger reserves.The desert locust (Schistocerca gregaria) is

specific to Africa, the Middle East, and India;it may occur in swarms and persist in a

region for as long as several years. Thatthose insects were known and revered, if notfeared, is recorded on ancient Egyptianfriezes predating the plagues. Transformedfrom solitary grasshoppers by as-yet-un-explained factors (presumably food-de-pendent), locusts swarm and become"gregarious," attacking all known standingcrops. They consume all plant crops andseedlings, acting to cleanse an area of allliving vegetation, whether food or not. Thelocust swarms, coming soon after the plagueof hailwhich would have damaged fruit-trees and vegetable cropswould have pre-cipitated great urgency on the part of theEgyptians to save their fallen, wiltingstands. Partially damaged crops would havebeen hastily carried to protected shelteredgranaries and underground storage facili-ties. The crops would have been broken anddampened by hail, damaged by immersionin fields, and contaminated by insect feces(rich in bacterial and fungal microorgan-isms 24

The Ninth and Tenth PlaguesDarkness andDeath of the EldestHowever darkness reigned over Egypt for

three days and nights, it prevented Egyp-tians from leaving their homes or even mov-ing within their homes. The Hebrews inGoshen were not affected by the ninthplague. Hort acknowledges Georg Ebers'sproposal that a volcanic eruption may haveaccounted for the phenomenon, but she notedno corroborative evidence. The same mightbe said for Velikovsky's theory of "gravel"from a passing comet. Hort's proposal thatthe darkness was due to a khamsin, a hotsoutherly wind coming from the Sahara, ismost convincing. She suggests that the fierce,hot winds would have picked up ultrasmallparticles of sand, creating a sandstorm so

John S. Marr and Curtis D. Malloy 17


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massive that it nearly eclipsed the sun in adark yellow haze. She notes that the particu-lar khamsin causing the sandstorm wouldhave to be the first of many experienced inEgypt during khamsin season (Marchthrough May), which is in keeping with hertimetable that the ninth plague must haveoccurred in March. The first of those sea-sonal windstorms would be the worst, pick-ing up all accumulated fine sand from theprevious year; once deposited on land, thesand would cause massive drifts and dunesof ultrafine sand in the lees of houses, mak-ing entrance and egress impossible. Severestorms (sobaa) commonly last for two orthree days, covering small houses and shel-ters. Years and decades of seasonal khamsinscause the disappearance of ancient monu-ments, tombs, and cities that archaeologistsare continuing to discover in the upper Nileregion of Egypt.25Hort is strangely cursory in her explana-

tion of the tenth plague, offering little in theform of exegesis. She considered the plaguean extension of the previous nine plagues inbringing the Egyptian Empire closer to star-vation. A novel interpretation offered is that"first-born" may have been an inadvertenttranslation of the Hebraic first-born n33 forfirst-fruits D'133 . She suggested that theHebrew people, who had normal stores of"corn," anticipated a conflict with Egyp-tians. The Egyptians were bereft of food (fishand meat), crops (wheat, barley, emmer,spelt, fruit), and even the ability to till soil(due to the death of the beast of burden).They could not expect new crops due to thedestruction of crops and new seedlings bythe preceding hailstorms and locusts. Theninth plaguea sandstormcovered theremaining tillable land.26

Alternative explanations also build on theaccumulative disruptions either exclusively

inflicted upon only Egyptiansthe fourth,fifth, sixth, seventh, and ninth plaguesorEgypt as a whole (including Goshen), thefirst, second, third, and eighth plague. Spe-cific diseases (e.g., anthraxm or typhoid), orcatastrophes (e.g., an earthquake) may, inpart, explain preferential deaths of Egyp-tians since Goshen was geographically sepa-rate and spared from those occurrences.Those explanations are nevertheless limited.First, the symptoms of anthraxcutaneousor pulmonicare fairly dramatic, as is thedestruction brought on by an earthquake. Ifthe account of the Ten Plagues includedboils and blains and a hailstorm, one wouldargue that a description of the symptomsand events around the tenth plague wouldalso have been offered. Neither an anthraxepidemic nor an earthquake are in concertwith previous plagues, building as they didon a theme of an impending famine causedby a decreasing supply of food.27

Hort's suggestion that death of the first-fruits (i.e., sprouts) may have been, morethan figuratively, the final insult. The cata-clysmic consequences of the last and mostserious plague (the death of an estimated 10percent of all humans and animals) is notstudiously considered by Hort. Hoyte, bycontrast, in considering the sequelae of acompromised food supply, offers an expla-nation of a form of food poisoning fromcontaminated foodstuffs (consumed by hu-mans and animals) as a possible cause. Thespecific infections causing the epidemic andzoonosis proposed by Hoyte are, respectively,typhoid fever (Salmonella typhi) and salmonel-losis (Salmonella typhimurium). Those two in-fections are posited because the former doesnot cause illness in animals and the lattercauses infection in both man and animals.They have different incubation periods(weeks for typhoid, days for salmonellosis).



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Both infections have different gastrointesti-nal and extragastrointestinal presentations.Both may cause death, but only after manydays or weeks of illnessnot immediately. 28

Possible clues to the cause of the tenthplague include (1) its unitary nature, (2) thevery lack of a description given to it, and (3)its sudden nature. Aside from an immediate,overnight death of large numbers of eldest-born humans and animals throughoutEgypt, no symptoms are recorded. As withanthrax, typhoid, salmonellosis, babesiosis,and an earthquake, an infectious disease ornatural calamity usually has physical mani-festations that might be expected to be notedand recorded. Only if man and beast were tobe suddenly, and quite literally, dropped intheir tracks, within minutes or hours afterexposure, would one expect no descriptionof prodromata, symptoms, or a prolongedclinical course. If such a single cause is of-fered and is in keeping with that premise, itshould also take into consideration the influ-ence of the previous nine plagues. Finally, itshould explain the preferential death of theeldest human and animal.Hypothesis for the Cause of the Tenth PlagueSuch an explanation for the tenth plague

does exist, but its very existence was notknown until a few years ago. What followsis a review of the preceding plagues andtheir consequences:

The freshwater supplies of the upperNile Delta were made undrinkable and,months later, suspect.

Fish, an important supply of protein,were lost for a time; they, like the water,were considered a suspect source offood.

Frogs died, allowing insects to multiplyunheeded.

Animal protein from cattle, sheep,goats, and swine were demonstrablytainted or reduced through illnesses.

Such draft animals as horses, donkeys,and oxen were afflicted, and harvestswere thus left largely unattended.

Field crops were destroyed by hail andwater, left to rot, or picked hastily.

Locusts consumed the remaining vege-tation, particularly young shoots thatmight have offered the hope of newcrops.

A sandstorm covered all obvious re-maining sources of food supplies, andprovided a blanket of warmth, humid-ity, and darkness for water-soakedfoodstuffs buried beneath the sand torot.

The 2.5 million people of the Egyptiannation were starving after ten months ofill fortune.

A mysterious affliction then killed theeldest Egyptian and the eldest of ani-mals in a sudden strike, without anyexplanation other than Yahweh's will.

Would any known natural phenomenonexplain the above? Noteworthy is Schoental,who first suggested that mycotoxins in con-taminating stored foodstuffs could explain

Egyptianhieroglyphics

(Reproduced withpermission fromWilliam j. Darby,Paul Clialioun-giii, and LouisGrivetti, Food:The Gift ofOsiris [NewYork: AcademicPress, 1977])

John S. Marr and Curtis D. Mallov 19


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the sudden death of Egyptian males andanimals. In a brief paragraph from a largerexposition, "Mycotoxins in the Bible," shesuggested that the most dominant humansand animals probably had the earliest accessto the stored, moldy food supplies, which ofcourse were fatal. The nature of those foodsupplies, the specific mycotoxin(s) infectingthem, the specific cause(s) of death, and thelogical explanation of a lack of symptoms forthose deaths could not be addressed, how-ever, as the causative agents had yet to beidentified.29Very much like species-specific arthropod

vectors and host-specific disease agents,mycotoxin-producing fungi are also plant-specific in foodstuffs they attack. Toxinsproduced by those fungi also vary in mu-tagenic, carcinogenic, and toxicologic prop-erties. By analyzing foodstuffs available toEgyptians (and their animals) at the time ofthe Exodus, one may be able to identifylikely candidate mycotoxins that may havecaused sudden illness in both humans andlivestock.30

Egyptian foods and food reserves havebeen well documented. Indeed, William J.Darby and his colleagues state that the sec-ond most important and powerful positionin the Egyptian government was keeper ofthe granaries because periodic famine hadinstilled careful planning on the part of thepharaohs. Most crucial of all foodstuffs werethe grains, specifically barley and wheat.The early precursors of what today is called"wheat" were, during the second millen-nium B.C.E., the precursor grains, spelt andemmer. Other grains in evidence at that timewere sorghum, rye, and "corn."31During the time of Thutmose III, barley

was largely used to make a primitive beer.Spelt and emmer was used to make bread,and stored as a commodity for future need

or trade. Sorghum was either limited in useor used for trade. Rye was not yet intro-duced. "Corn," as translated by the Scrip-tures, must have been any early form ofwheat since true "corn" (maize), as we knowit, is a New World vegetable. The talmudicand biblical terms "corn" must, by force,signify a wheatlike product, perhaps emmeror spelt. A distinction among those grains isimportant, since it allows a differentialanalysis to be made regarding mycotoxins.More than one hundred toxigenic fungi

have been identified since the first myco-toxin, aflatoxin, was discovered in 1961.Dozens have been identified as causingnatural outbreaks in human and animalpopulations; only a few, however, have beentraced to standing or stored grains of eco-nomic importance used for food and fodder.The specific genera of those fungi areClaviceps, Aspergillus, Penicillium, Fusarium,and a variety of lesser organisms. The mostpotent mycotoxins within those four generathat are specific for wheat are the stachybotryo-toxicoses produced by Fusarium graminearutnand Stachybotrys atra. The mycotoxins pro-duced (macrocyclic trichothecenes) havebeen linked to the deaths of thousands ofpeople and animals in the former USSR dur-ing World War II, as well as a variety oflivestock (poultry, cattle, horses, sheep, andswine) in many countries. Humans ingestproducts from grain, such as bread; poultryeat grain, equids consume fodder, and rumi-nants (cows, oxen, and camels) eat straw. (Ofinterest, ruminant animals are preferentiallyattracted to damp straw on which S. atragrows.)32More recently, S. atra mycotoxins caused

illness and deaths in humans who have hadno direct contact with mycotoxins other thaninhaling them. Trichothecene mycotoxinsproduced on walls and basement floors in



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j rr ir rrg =He gave them hail - stones fc r rain ; o tire *^m r r w ^

i

He gave them hail - stones tor tain

r r r i mUiLj i rfrjg i PfLgjs

mrrogflg^ir r > ' '' rgs ^-J3Q

Handel's interpretation of the plague of hail, in Israel in Egypt

water-damaged buildings were carried totheir victims through ventilation systems. Asimilar exposure in a farming couple causedbronchiolitis in the man and acute renal fail-ure in the woman, both of whom had beenworking in a silo and were exposed to Asper-gillus ochraceus. Mycotoxins have also beenhypothesized as an explanation for illnessand death among archaeologists, made fa-mous in the so-called "King Tut's curse."33(The Earl of Carnarvon, discoverer of KingTut'ankhamun's tomb, died of unexplainedpneumonia in 1922.)Although macrocyclic trichothecenes

vary in toxicity and cytotoxicity in labora-tory animals, it is apparent that very smallamounts cause illness and death. Fusty, diminimis amounts of S.


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products. Subsequently, once granaries hadbeen aired, the inhalational route was nolonger a factor. In addition, deeper stores ofwheat and barley may have not been asheavily contaminated by the surface-grow-ing fungi, and therefore, relatively safer toeatsparing less powerful man and beast.The Hebrews in Goshen, who had experi-enced neither the calumny of tainted fishand meat nor the destruction of crops, norfamine, would also have avoided the mass-poisoning due to those mycotoxins.

That, then, is our explanation for the mostdevastating, tenth and last plague of Egypt,and the proceeding plagues that may havecontributed to it. Numerous theologiansand biblical scholars have authored pre-vious, significant, original, and unique con-tributions to the eclectic interpretation ofcauses of the Ten Plagues (most notablyHort, Hoyte, and Schoental). We greatly ac-knowledge their hypotheses and add ourinterpretation and a final synthesis to thatimpressive collection of literature. It is atragic and powerful story oftwo proud peo-plesthe Egyptians, under Thutmose III atthe height of their empire, and the people ofIsrael about to become a nation. We hopethat others might wish to begin where weconcluded, and to follow with their owninterpretations.We end with this note: The long Jewishtradition about the first Passover began atthe end of the ninth plague. It is a celebrationof the first meal to mark the Hebrews' escapefrom the many plagues, and from the tenthplague. The Passover celebration consists ofeating symbolic newborn, healthy lambshank, fresh herbs, and horseradishallsafe from mycotoxin exposure. It also re-quires eating unleavened bread made from

fresh flour, which is, by definition, free ofany yeasty or other mycotoxin contamina-tion.

Notes1 Curtis. D. Malloy et al., "Emerging Pathogens:

The White Horse of the Apocalypse?" Journal ofPub-lic Health Management and Practice 1 (1995): 48-61;Mary E. Wilson, Richard Levins, and Andrew Spiel-man, eds., Disease in Evolution: Global Changes andEmergence ofInfectious Diseases, vol. 740, Annals of theNew York Academy of Sciences (New York: Acad-emy of Sciences, 1994), 1-503.

2. All references are to the Authorized (KingJames) Version.

3. Immanuel Velikovsky, Worlds in Collision(Garden City, N.Y.: Doubleday, 1950), 49; Velik-ovsky, Ages in Chaos (London: Sphere Books, 1973),41-44; "The Admonitions of Ipuwer, PapyrusLeiden 344, Recto," in Ancient Egyptian Literature: ABook of Readings, ed. Miriam Lichtheim, 3 vols.(Berkeley: University of California Press, 1973),1:149-63.

4. Greta Hort, "The Plagues of Egypt," Zeitschriftfur die Altesttamentliche Wissenschaft 69 (1957): 84-103;Hort, "The Plagues of Egypt," Zeitschrift fur die Al-testtamentliche Wissenschaft 70 (1958): 48-59.

5. Donovan A. Courville, Tlie Exodus Problem andIts Ramifications (Loma Linda, Calif.: ChallengeBooks, 1978), 116-32; Tlie Ten Commandments, Para-mount Pictures, Hollywood, Calif., 1956; WernerKeller, The Bible as History (New York: William Mor-row and Co., 1981), 122; H. M. D. Hoyte, "ThePlagues of Egypt: What Killed the Animals and First-born?" Medical Journal ofAustralia 158 (1993): 706-8;John J. Bimson, Redating the Exodus and tlw Conquest(Sheffield, Eng.: Almond Press, 1981); John Bainesand Jaromir Malek, Atlas ofAncient Egypt (New York:Facts on File, 1989), 36.

6. Baines and Malek, Atlas, 36.7. Martin Gilbert, Jewish History Atlas (London:

Weidenfeld and Nicolson, 1976), 312; Courville, Exo-dus Problem, 116-32.

8. It is interesting that Isaac Asimov, in his com-prehensive Asimov's History of tlie Bible: The Old Tes-tament, providedno interpretation regarding the TenPlagues. See Asimov's History of the Bible: The OldTestament (New York: Doubleday, 1968), 1-1295.



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9. Jacob Bryant, Observations upon tlie Plagues In-flicted upon the Egyptians (London: Hamilton and H.Ogle, 1810), 1-392. Velikovsky's book and his theo-ries cannot be expanded upon here. However, itmust be noted that his hypothesis about a comet andits subsequent damage, ostensibly incredulous whenhe wrote his book in 1950, may be partially substan-tiated by "Bits of Mars Hit Africa in '62, ResearchersSay," New York Times, March 31, 1995, A16, whichsuggests that an explosion on Mars millions of yearsago produced material that landed on Earth at leastthree times, the most recent of which was in Nigeria.Furthermore, Velikovsky's belief that a volcaniceruption might have served as one of many cataclys-mic catastrophes causing the plagues of Egypt issupported by a 1783 volcanic eruption described inStuart Flexner with Doris Flexner, Tlie Pessimist'sGuide to History (New York: Avon Books, 1992), 95.

10. P. A. Tester, "Harmful Marine Phytoplanktonand Shellfish Toxicity: Potential Consequences ofClimate Change," in Disease in Evolution, 69-76; E. C.D. Todd, "Emerging Diseases Associated with Sea-food Toxins and Other Water-Borne Agents," in Dis-ease in Evolution, 77-94; Wayne W. Carmichael andIan R. Falconer, "Diseases Related to FreshwaterBlue-Green Algal Toxins and Control Measures,"Algal Toxins in Seafood and Drinking Water, ed. Fal-coner (London: Academic Press, Ltd., 1993), 188-209;JoAnn M. Burkholder, H. B. Glasgow, and Karen A.Steidinger, "Unravelling Environmental and Tro-phic Controls on Stage Transformations in the Com-plex Life Cycle of an Ichthyotoxic 'Ambush Predator'Dinoflagellate," abstract from the Sixth InternationalConference on Toxic Marine Phvtoplankton, Nantes,France, Oct. 18-22, 1993.

11. William J. Darby, Paul Ghalioungui, andLouis Grivetti, Food: The Gift of Osiris, 2 vols. (NewYork: Academic Press, 1977), 1:337.

12. Personal communication from Richard L.Brown, Ph.D., Curator, Mississippi EntomologicalMuseum, Mississippi State Universitv, July 24, 1995;Defense Pest Management Information Center, Dis-ease Vector Ecology Profile: Egypt, Technical Informa-tion Bulletin (Washington, D.C.: Forest Glen Section,Walter Reed Army Medical Center, 1988), 1-48.

13. Personal communication from David J.Sencer, M.D., M.P.H., Centers for Disease Control(retired), July 27, 1995.

14. Hoyte, "Plagues of Egypt," 706-8.15. Disease Vector Ecology Profile.16. Maurice T. James and Robert F. Hanvood,

Herms's Medical Entomology, 6th ed. (New York:Macmillan and Company, 1969), 161-64.17. Hoyte, "Plagues of Egypt"; Charles T. Brues,

"Geographic Distribution of tlie Stable Fly, Stomoxyscalcitrans," journal of Economic Entomology 6 (1913):459-77; Brown communication.

18. Hoyte, "Plagues of Egypt," 706-8.19. Abram S. Benenson, ed., Control of Communi-

cable Disease in Man (Washington, D.C.: AmericanPublic Health Association, 1990), 17.

20. Committee on Foreign Animal Diseases, For-eign Animal Diseases (Richmond, Va.: United States

Animal Health Association, 1992), 1424; Benenson,Control of Communicable Disease, 54; Paul F. Crane-field, Science and Empire: East Coast Fever in Rhodesiaand the Transvaal (Cambridge, Eng.: Cambridge Uni-versity Press, 1991), 1-385.

21. Committee on Foreign Animal Diseases, For-eign Animal Diseases. According to Rabbi NossonScherman, the fifth plague could not have killed allthe animals of Egypt (as verse 6 states) but only theanimals in the field. Spared were all animals inGoshen, sheltered Egyptian ruminants and equids,and domestic household pets. That interpretationfacilitates the explanation of the next epidemic,when both humans and surviving "beasts" wereafflicted. It also allows for a solution to the questionof where the pharaoh obtained the horses necessaryto pursue the Hebrews during the subsequent Exo-dus. Scherman, Tlie Chumash: The Torah: Haftaros andFive Megillos with a Commentary Anthologized from theRabbinic Writings, ArtScroll series (Brooklyn:Mesorah Publications, Ltd., 1993), 1-313.

22. Hort, "Plagues of Egypt," 69: 84-103, and 70:48-59; Henry W. Blanc, Anthrax: The Disease of theEgyptian Plagues, rpt. from Neiv Orleans Medical andSurgical journal, July 1890; G. Ceccarelli, "Le diecipiaghe d'Egitto e la loro interpretazione medica,"Minerva Medica 85, no. 5 (1994): 271-77; ReginaSchoental, "A Corner of History: Moses and Myco-tox&&" Preventive Medicine 9 (1980): 159-61; Schoen-tal, "Mycotoxins and the Bible," Perspectives inBiology and Medicine 28 (Autumn 1984): 117-20.

23. Committee on Foreign Animal Diseases, For-eign Animal Diseases.

24. Robert A. Cheke and Johnson Holt, "ComplexDynamics of Desert Locust Plagues," Ecological En-tomology 18 (1993): 109-15; Darbv et al Food, 1:337.25. Hort, "Plagues of Egypt,'" 70: 48-59; Velik-ovsky, Worlds in Collision; personal communicationfrom W. Benson Harer, Jr., physician and Egyptolo-gist, July 20, 1995.

26. Hort, "Plagues of Egypt," 70: 48-59.27. Velikovskv, Worlds in Collision; Vehkovsky,

Ages in Clmos; Hort, "Plagues of Egypt," 69: 84-103and 70: 48-59; Benenson, Control of CommunicableDisease, 17; Schoental, "Corner of History," 159-61;Ludwig Schmidt, Beobachtungen :u der vlagenerza-hlung in Exodus V1I14-XI W (Leiden: E. J. Brill, 1990),1-23; M. G. Jacoby, "The Fifth Plague of Egypt,"journal of the American Medical Association 249 ( 1983):2779-80'.

28. Hoyte, "Plagues of Egypt," 706-8; Benenson,Control ofCommunicable Disease, 469, 381.

29. Schoental, "Corner of History," 159-61;Schoental, "Mycotoxins," 117-20.

30. Raghubir P. Sharma and Dattajirao K. Sa-Lunkhe,Mycotoxins and Phytoalexins (Boca Raton, Ha.:CRC Press, 1991), 68-73. "

31. Darby et al., Food, 457-99.32. Sharma and Salunkhe, Mycotoxins, 68-73; D.

Carleton Gajdusek, Alimentary Toxic Aleukia in AcuteInfectious Hemorrhagic Fevers and Mycotoxins in theUnion of Soviet Socialist Republics, Medical SciencePublication, no. 2 (Washington, D.C.: Army Medical

John S. Marr and Curtis D. Malloy 23


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Service Graduate School, Walter Reed Army Medi-cal Center, 1953), 34.

33. W. A. Croft, "Airborne Outbreak of Tricothe-cene Toxicosis," Atmospheric Environment 20 (1986):542-52; personal communication from EduardoMontana, M.D., Centers for Disease Control andPrevention, Atlanta, June 25, 1995; N. DiPaulo et al,"Inhaled Mycotoxins Lead to Acute Renal Failure,"Nephrology Dialysis Transplantation 9, suppl. 4 (1994):116-20.

34. Sharma and Salunkhe, Mycotoxins, 1-775;Eckardt Johanning, "Health Problems Related toFungal Exposure: The Example of Toxigenic Stachy-botrys Chartrum Atra," Fungi and Bacteria in IndoorAir Environments, ed. Johanning and C. S. Yang (NewYork: Eastern New York Occupational Health Pro-gram, 1995), 169-82.

JOHN S. MARR is Medical Director of M.D. HealthPlan, a health maintenance organization based inNorth Haven, Connecticut. A graduate of YaleUniversity, he earned an M.D. from New York MedicalCollege and a master's degree in public health fromthe Harvard School of Public Health. He is boardcertified in internal medicine, preventive medicine,and occupational medicine. Previously he served asDirector of the Bureau of Preventable Diseases andPrincipal Epidemiologist in the New York CityDepartment of Public Health. The author of threebooks on children's health, he is coauthor of BlackDeath (Dutton and Ballantine), a novel about bubonicplague, and has completed a second novel on thecontemporary equivalents of the Egyptian plagues.

ACKNOWLEDGMENTSThe authors would like to acknowledge Richard L.Brown, W. Benson Harer, Jr., Eduardo Montana, andDavid J. Sencer, whose communications enriched thispaper. They also acknowledge the followingindividuals, who greatly assisted their efforts inlocating citations, reviewing the manuscript, andproviding additional information and assistance: LouisN. Sorkin, R.P.E., Department of Entomology,American Museum of Natural History; Roger Breeze,D.V.M., Acting Area Director, U.S.D.A. AgriculturalResearch Service, Region II, Athens, Ga.; Kathleen A.Hanlon, D.V.M., Ph.D., Deputy State Public HealthVeterinarian, Zoonoses Program, New York StateDepartment of Health, Albany; John P. Woodall, Ph.D.,Director of Arbovirology Laboratory, WadsworthLaboratories, New York State Department of Health;Rabbi Harvey Goldscheider, Temple Beth El, NorthBellmore, N.Y.; Stephen Berger, M.D., Chief, InfectiousDiseases, Medical Center Tel-Aviv Ichilov Hospital,Tel-Aviv, Israel; Helen Hubbard Marr, New York StateCouncil of the Arts; John D. Debbie, D.V.M., ChiefVeterinarian, New York State Department of Health;Roberta L. Jainchill, New York State Department ofHealth, Bureau of Tuberculosis Control, MetropolitanNew York Regional Office; John Klein, Ph.D.,University of Missouri at Columbia; Diane E. Monroe;Sandra M. Gould, M.I.A.; and Leo Cuccia and Anne vonStulpenagel for their translations of Italian and Germanmedical journal articles.

CURTIS D. MALLOY received the baccalaureate fromPacific Lutheran University and the Master of PublicHealth degree from Columbia University. He is aResearch Associate with Medical and Health ResearchAssociation of New York City, Inc. His researchinterests include epidemiology, infectious disease,and international health.



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Cholera: Outlook for the Twenty-FirstCenturyJohn P. Craig

Cholera is at once the best understood ofinfectious diseases and also the most

unpredictable in its appearance in time andplace. Treatment is among the most success-ful in all of medicine, yet prevention is diffi-cult to achieve. An approximation of thesketchy history of cholera epidemics andpandemics of the nineteenth and twentiethcenturies as recorded by Western observersis shown in Figure 1.

Asiatic cholera was first recognized byWestern medicine in the second decade ofthe nineteenth century, and medical histori-ans have recorded seven pandemics sincethen. A quick scan of Figure 1 might suggestto the skeptical observer that the division ofthe human cholera experience into sevenpandemics has been quite arbitrary becauseit shows pretty clearly that since 1817 wehave been in the throes of cholera epidemicsmore often than not. What is most fascinat-ing and still unexplained is that there havebeen occasional periods during which chol-era seemed to vanish from all parts of theWestern worldat least to undetectable lev-elsand then resurfaced in unanticipatedregions. No other infectious disease capableof causing such high rates of morbidity andmortality has exhibited that manner of re-current epidemic explosiveness followingnear-total disappearance from all parts ofthe world except for its permanent annual

Pandemic and Epidemic Cholera: 1817-1995

VI

|Europe

erica ( viav Orleans

AfricaEu'opeAmerica

EgyplRussiaWesiern EuropeEngland

1937194019451947

VII

I"" :;l

I CentraliH

El TorBiotype01 Serotype

0139Serotype

Fig. 1. Years and regionsof the Seven CholeraPandemics.

presence in the Gangetic delta of the Indiansubcontinent.

Three Steps ForwardDuring the era shown in Figure 1, lasting

more than a century and a half, there havebeen three major bursts of enlightenmentconcerning the disease. The first recognizedits contagious nature; the second revealed

CADUEUS Spring 1996 Vol. 12. No. 1


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the microbial agent responsible; and thethird, coincident with the current SeventhPandemic, has disclosed the essentialmechanisms of pathogenesis and has pre-scribed an astonishingly effective therapy.Unlike several other human scourges inwhich pathogenesis and treatment havebeen elucidated much less successfully,however, cholera has defied our attempts todevelop a truly effective and applicable im-munizing agent. It still eludes our efforts tounderstand the factors that determine itsperiodic emergence in epidemic form. Chol-era stands in striking contrast to smallpox,in which the most eminently successful of allvaccines was perfected, applied, and led tothe eradication of the disease before themechanisms of pathogenesis were fully un-derstood (and before any treatment of sig-nificance had been devised).

All three bursts of enlightenment in chol-era followed on the heels of a new pandemicthat provided investigators with an abun-dance of patients and the opportunity tostudy them.The first was John Snow's recognition ofthe contagious nature of the disease and itsdependence on drinking water for entry intothe human host. 1 Snow postulated duringthe 1854 cholera epidemic in London that amateria morbis capable of replicating in thehuman host was transferred from one pa-tient to the next in the diluted liquid dis-charges that found their way into the waterdistribution system. Snow also proposedthat once the entity had reached the bowelof the next victim it multiplied and pro-duced a poison that caused the bowel tosecrete its normal intestinal juice in prodi-gious quantities, thus leading to the well-known voluminous secretory diarrhea andhypovolemic shock that characterizes the se-vere form of the disease. Snow's series of

observations and his brilliant and simpleexposition of his findings represented a fun-damental leap into a new dimension of un-derstanding of infectious disease, decadesbefore the microbial era. A careful readingof his scholarly treatise will disclose anastonishing prescience in his descriptionsand in his interpretations of his findings.The second burst of understanding came

with Robert Koch's discovery in Egypt dur-ing the Fifth Pandemic that a bacillus, whichhe dubbed Vibrio comma, is the probable mi-crobial agent of the disease.2 Koch was un-able to fulfill the third of his ownpostulateswhich he proposed as the pre-requisites for proof of causality of any dis-ease.3 Nevertheless, he laid the foundationfor the spate of research that followed eightyyears later when the Seventh Pandemic re-kindled the curiosity of the medical worldand led to a clearer understanding of themanner by which Snow's materia morbiscould wreak such sudden havoc on its vic-tims. It was left to Richard B. Hornick andhis associates at the University of Marylandto fulfill the third of Koch's postulates withlandmark studies that reproduced typicalclinical cholera in volunteers in 1971.4The third burst of understanding about

the nature of cholera was stimulated by thecurrent Seventh Pandemic, which began in1961. Thus, since the 1960sand continuingtodaythere has been a steady outpouringof research that has led to a detailed under-standing of the structure of Koch's kom-mabacillus (now renamed Vibrio cholerae)and of its many productsmost notably thecholera enterotoxin, an excreted protein thatappears to be the chief but probably not thesole entity responsible for the hypersecre-tion of succus entericus that Snow so elo-quently described more than a centuryearlier. 5

26 Cholera


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Although scientific literature nowabounds with studies dealing with themechanisms of pathogenesis of cholera, it ismy opinion that the seminal work that firedthe imaginations of all who followed wasthat of Sambhu Nath De of Calcutta.6 Deshowed in 1958, just before the beginning ofthe current pandemic, that the cholera vibrioproduces an enterotoxin that is responsiblefor the dramatic fluid and electrolyte lossesthat make the disease so feared and re-spected. It is also abundantly clear that themajor biomedical triumph emerging fromthe laboratory and clinical research stimu-lated by the massive morbidity of the Sev-enth Pandemic has been the near-perfectionof the treatment of patients with cholera. Itis an unparalleled victory in the annals ofmedicine and is the result of years of pains-taking clinical investigation by scores ofphysicians from many countries. Today, inthe hands of well-trained physicians (and,even more notably, paramedical personnel),there can be a 99 percent survival of patientswith even the most severe form of the dis-ease with the proper use of intravenous andoral fluid and electrolyte replacement ther-apy. In no other disease in which untreatedpatients suffer such high fatality rates cansuch dramatically successful results be evenhoped for. That fact was triumphantly dem-onstrated in the present ongoing epidemicin South and Central America (vida infra), inwhich local physicians and other health caredeliverers achieved just such near-miracu-lous salvation of life with less than one per-cent case-fatality rates.

Cholera is thus unique in that at presentthe protection of human life depends upontreatment of the disease after onset ratherthan prevention by vaccination or interrup-tion of transmission. The latter may appearironic upon first thought; unlike an airborne

infection we clearly know how to disinfectan individual's intake of food or drink, butbecause of our ignorance of the ecology ofvibrios in the environment, that theoreticalknowledge cannot yet be translated into re-alistic protection of most of the communitiesor societies of our world. An approach thatdiffers

CADUCEUS - Volume 12 - Number 1 - Spring 1996

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