The Infectious Myth Busted: Is Plague Contagious?

Examining the notion of person-to-person transmission.

The first major efforts to investigate the problems of plague were made in the early 1800s in Egypt. The French Government sent a commission to study the disease, consisting of four members, headed by Dr. Clot Bey.

Three of the four members concluded that the disease was non-contagious.

“The first sustained and concerted efforts to investigate the problems of plague were made early in the nineteenth century in Egypt. The French and Russian Commissions, which worked at intervals between the years 1828 and 1843, had the distinction of being the first to be expressly appointed for this purpose. In 1828 the French Government sent a Commission to study the disease, and in 1835 the better known Commission headed by Clot Bey—the other members being Gaetani Bey, Laehezè, and Bulard—worked for seven months in Cairo and Alexandria, and excited a lively controversy on the question whether plague is or is not contagious; except Bulard they were firmly persuaded that it is not transferable.”

Clot Bey was an influential anti-contagionist of the early 1800s, and served as Chief Physician to the Viceroy of Egypt and Inspector-General of the Egyptian civil and military medical services.

Clot Bey

For over thirty years he had insisted on the non-contagiousness of plague, and applied the same reasoning to cholera and yellow fever. In 1835 he had, in the presence of several physicians, pharmacists, and public officials, inoculated himself on two occasions with the pus and blood from a plague victim without suffering any ill effects. He also inoculated various animals with negative results.

“[Clot Bey] tested the infectivity of plague materials on his own person. He inoculated himself on two occasions, with the blood of a patient and again with pus from a bubo; he also inoculated various animals. All his experiments were negative.”

Clot Bey inoculating himself with a sample from a plague victim. He remained unaffected.

To the question “Is the plague propagated by contagion?” Dr. Clot Bey answered:

“I repeat, it has been demonstrated to me by a profound study of the history of this disease, and especially by the numerous facts that I have myself observed, or which have been made known to me by all the medical men who have had to combat the plague in Egypt lately, that the plague is never propagated by contagion.”

In 1866, he published his fourth book on plague under the title Last Words on the Non-Contagion of Plague.

The book contains a section about the non-contagiousness of the last major outbreak of plague in Western Europe, The Great Plague of Marseille, which occurred the year 1720 in France.

The Great Plague of Marseille

Clot outlines the experience of several doctors of the time. These eminent men, neither in practice nor in theory, recognized the contagious nature of the plague. They treated many sick people, touched them, sat on beds of plague victims, and opened corpses without taking any precautions.

“As for the transmission of the disease through contact, it is also rejected by Dr. Deidier, as well as by his colleagues Chicogneau and Verny, professors from Montpellier, who were also sent to Marseille by order of the king. These doctors stayed a whole year in Marseille. They were able, therefore, to observe the disease throughout its duration. Note that they were very remarkable, very educated men, especially Chicogneau, who was, for many years, the king’s first physician. Well, these men, neither in practice nor in theory, recognized the contagious nature of the plague. In practice, they treated many sick people, touched them, sat on beds of plague victims, and opened corpses without taking any precautions. In theory, that is to say in the works that they published reporting the results of their observations, they declared themselves anti-contagionist.”

Google translate was used.

This experience is reinforced several doctors who were familiar with the plague.

Mr. Laidlaw, surgeon to the European hospital at Alexandria stated that he had seen numerous examples of people who had been in direct contact with plague patients who remained unaffected.

“I have under my eyes numerous examples of persons in health who have been in direct contact with plague patients, and who, nevertheless, have not been attacked: when the disease enters the family all do not fall victims; the persons who attend the sick continue healthy and well; those who render the last duties to the dead are not affected. I have seen a daughter, in spite of the supposed danger, throw herself on the body of her mother and embrace it until it had been carried away. I have seen a father raise his dying son, covered with plague blotches, in his arms, and retain him there until he had died.”

Dr. Abbot was an english surgeon who recognized the non-contagiousness of the disease. He and his assistants were in close contact with the sick without protective measures, but none of them became sick. He knew several medical men who performed post-mortem examinations of plague patients, without taking the disease.

“I myself not only touched my patients every quarter of an hour, but obliged my assistants to touch them, and also to sit upon their beds, and there to remain until relieved, to administer the remedies prescribed. Neither I nor my assistants were attacked by the disease.” “I have known,” says he in another place, “several medical men, who, while the plague was raging with its greatest violence, persisted in making post-mortem examinations of plague patients, escape without taking the disease.”

“Mr. Abbott says that “He never used any kind of fumigations, oiled-silk gloves, nor any other absurdities.”

In 1841, Dr. Robertson, the general medical officer of the troops in Syria, expressed his doubts over the contagiousness of plague.

“In reference to the contagiousness (transmissibility) or non-contagiousness of this, at times, frightful disease, I beg to state that the result of all my experience leads me to believe that the disease originates in local causes, and that it is not highly contagious. My firm conviction is that the plague cannot be communicated from one person to another in a pure atmosphere, even by contact.”

Mr. Brant, of Erzeroum, stated that his experience led him to doubt the contagious nature of the disease.

“As far as my experience goes I have been led to doubt the contagious nature of the disease, or, if contagious, it must be in a very slight degree. I have had within the sphere of my observation many cases of the most complete and extensive contact, without the disease being communicated.”

Sandison, of Brussa, declared that there are numerous instances of people who escaped the disease after contact with the sick.

“The cases are numerous in which persons escape the disease after contact with persons seized with it, even in its most malignant stage.”

The Royal Academy of Medicine of France reported that there was no evidence for the contagiousness of plague.

“In 1844 the Royal Academy of Medicine of France, after a very thorough and exhaustive research in Egypt, reported:

“There is not a single fact which indisputably proves the transmissibility of the plague by mere contact with the sick.”

Not only was the mere contact of diseased secretions and morbid productions unattended with danger, but the introduction of these substances into the blood was not followed by any fatal result.

In 1803,

“M. Valli, an Italian physician, inoculated twenty-four persons with a mixture of variolous and plague matter.”

Dr. Sola, also, a Spanish physician,

“inoculated fourteen deserters condemned to death, in 1818, at Tangiers, with a mixture of plague matter.”

But these people remained unnaffected.

“Be this as it may, neither in this instance, nor yet in the former, were those inoculated attacked with plague.”

After the plague of 1835 at Cairo in Egypt, the clothes of 50,000 plague victims were sold. Not a single single case arose among either the dealers or the purchasers. More than 600 houses became empty due to the plague deaths. These houses were examined by authorities, but not single person engaged in this service became ill.

“After the plague of 1835 at Cairo, the clothing, effects, etc., of 50,000 plague patients, who had been carried off by the pestilence, were sold in the public bazaars, without, as far as known, a single case arising among either the dealers or the purchasers. More than 600 houses remained tenantless in the city for several months; they were then ordered to be visited by the civil authorities, and an inventory was taken of their several contents. Not one of the persons engaged in this service fell sick. It is evident, therefore, that neither the infected themselves, nor their belongings, are capable of conveying the disease.”

The clothes of 50,000 plague victims were sold. Not a single person became sick as a result.

The Egyptian army suffered from plague in 1826, 1827, and 1828 in Greece. They returned to Egypt in 1928 and sold the clothes of the dead soilders. Yet, not a single case of plague was observed that year in Egypt.

“The Egyptian army, which then occupied the country, suffered severely from the plague which raged in the Morea in 1826, 1827, and 1828. In September of the last year, the troops returned to Egypt, and the clothes of all the soldiers who had died, both of the plague and of other diseases, were taken to Alexandria, deposited in the magazine of a barrack, and eventually sold. Nevertheless, not a single case of plague was observed that year in Egypt.”

The French Plague Committee reported that people wore the clothes of plague victims without being affected.

“Numerous facts prove that the clothes which have been worn by infected persons, when made use of by other persons, have not communicated the disease, although they had not undergone any kind of purification.”

Plague broke out in India in 1896. A plague hospital was subsequently opened on February 19th, 1897, and closed on June 26th, 1897. During these months, 630 patients were admitted, 304 were acute plague cases.

No instance of the transmission of the disease from a plague victim to another patient occured.

“No instance of the spread of the disease from convalescents to patients near them under observation or suffering from other diseases was met with. The body of a patient dead of plague does not seem to be capable of communicating the disease.”

There were more than 240 people who attented the sick, and in not a single instance did the disease spread to the visitors.

“That the disease is not infectious in hospitals is a well-established fact from experience in the Parel Hospital. In upwards of 240 instances the friends of the patients attended their sick, and in twenty instances scarcely even left the bedside, and in not a single instance did the disease spread to the friends.”

“The conclusion drawn is that one of the safest places during an epidemic is the ward of a sanitary plague hospital.”

The plague victims did not transmit the disease to anyone in the hospital.

This experience is reinforced by several observers.

Dr. Pezzoni stated that people working in plague establishments appeared to be invulnerable to the disease, despite close contact.

“Nurses, and other persons employed in plague establishments, appear to be invulnerable to the disease, since they remained both day and night with plague patients in perfect impunity, dressing their wounds, making their beds, and rendering them every sort of help.”

According to Dr. John Bowring of Edinburgh, cases in which contact did not communicate plague were abundant.

“Mothers frequently die of the disease without communicating it to their sucking children,—husbands and wives without conveying it to their partners. Plague patients constantly expire in the arms of others and no evil results.”

“Cases of the disease after communication with plague patients no doubt occur; but it by no means follows that the contact was the cause.”

Dr. Bowring noted that clothing were used indifferently for plague and other patients, and that no communication of the plague occurred therefrom.

“At the Mussulman hospitals, where plague almost always occurs in certain months, I found that the lint and linen were used indifferently for plague and other patients, and that no communication of the plague occurred therefrom. In fact, nothing has been found so difficult as to communicate it.”

Contact with the sick was not a factor in the causation of the disease.

Dr. Charles Maclean outlined the non-contagious character of plague in a 1825 publication.

“ [Plage] is not communicated by wearing clothes impregnated with the sweat, pus, and ichorous matter from the bodies of those who have died of the malady; it is not communicated by sleeping in the uncleansed beds of those who have perished of it; it is not communicated by coming into the closest possible contact with their living body; it is not communicated by sleeping in the same bed with them; the husband who dies in the arms of his wife communicates it not to her; sister communicates it not to sister; the child deriving sustenance from the breast of its mother, who is perishing, and who does perish by it, receives it not; the sick who fly for succour to a purer air, impart it not to the inhabitants of these more favoured places; whole armies continue in unrestrained and constant intercourse, with affected towns and villages, without receiving it a single instance”

Maclean published a book in 1824 entitled Evils of Quarantine Laws, and Non-existence of Pestilential Contagion.

“It has been shown that pestilential contagion, upon a belief in which these [sanitary] laws were originally founded, has no existence.”

In 1906, Dr. J. A. Thompson published a paper entitled On the Epidemiology of Plague. In the end of an extensive investigation, Dr. Thompson concluded that there was no evidence for sick-to-well transmission of plague.

“The evidence, then collected under the usual conditions of civilised life in 1900 and in 1902, suffice to show that neither direct nor indirect communication with the sick is a factor in the causation of epidemics, and this fundamentally important judgment has been fortified by all the experience of subsequent years. It carries with it the corollary that the infection spread in epidemic form by means which were (a) external to man, and (b) independent of his agency.”