DISEASES AND EPIDEMICS

The nineteenth century was a time of dramatic change for American medicine. By the end of the century, the practice of medicine had acquired some of the characteristics of a science. Until then, medical care had been based on a belief system that did not recognize health and disease as separate and distinct entities; instead, the standard thinking was that each person possessed relative degrees of healthiness and sickliness, which coexisted in a treacherously shifting state of unsteady balance. The writings of the ancient Greek physician Claudius Galen (129–c. 199 c.e.) had been the dominant medical authority for two thousand years. Medical knowledge was stagnant, and medical practitioners of the early nineteenth century did not have any real appreciation of the nature or basis of any of the disease processes they encountered. They were not aware that specific diseases could be linked to defined biological processes such as bacterial infections. Instead, vague and generalized theories of total body dysfunction were employed to account for every type of illness. Therapeutic interventions were not based on research in physiology, pathology, and pharmacology but instead were derived from beliefs and expectations centered upon emotions, philosophies, hopes, desires, cultural considerations, and the individual idiosyncrasies of each person. The medical historian John Warner has cited a Cincinnati practitioner of 1848 who wrote that "disease is not an entity, or real existence, but is only the organic and functional forces, or powers of life, modified by perversion of activity" (p. 63). The medical condition of every person was considered to be nebulous, uncertain, and at risk for unexpected change for the worse due to the constant interactions between each person's own constitutional makeup and the antagonistic forces of each individual's environment.

The commonplace events in the life of the average human—teething, puberty, menstrual cycles, and even the change in weather with each new season—were considered to be among the potentially unsettling and destabilizing events leading to the unhealthy imbalance contained within each person. As Charles Rosenberg describes the prevailing understanding, the body was "a kind of stew pot, or chemico-vital reaction, proceeding calmly only if all its elements remained appropriately balanced. . . . the body was a city under constant threat of siege" (p. 13). In the absence of knowledge about specific diseases, there could be no targeted therapy for any specific ailment. Instead, the role of the physician was to readjust the imbalance by manipulating the intake and outgo of the disordered system. Typically this was accomplished through adjusting the balance of the body's fluids and secretions by removing blood, stimulating perspiration or urination, or purging the gastrointestinal tract through drugs that induced vomiting or diarrhea. In theory, diseases could be either "sthenic" (strong) or "asthenic" (weak), but in practice virtually all were sthenic and therefore required treatments that would decrease the patients' level of animation. "Draining off excess excitement from the body was not entirely metaphorical" (p. 92), Warner explains, but in fact was the basis for the use of bloodletting, cathartics, emetics, and counterirritants. Restoring the body's delicate balance was serious business, and huge ("heroic") doses were required so the patient would have no doubt about the gravity of the treatment.

After centuries without significant change in philosophy or methodology, however, medical practice began to acquire a more scientific perspective. The greatest advances during the nineteenth century occurred in Europe. The newer approaches caught the attention of medical practitioners in the United States, and many of the wealthier and better-educated American physicians flocked to Paris from the 1820s through the 1860s in search of better medical training than they could obtain in the United States. The emphasis of Parisian medicine was on the healing power of nature, an attitude that was an abrupt departure from the aggressive interventional approaches of traditional American medicine. The French approach to medical care was observational rather than interventional, and for the first time large amounts of information on the natural history of specific disease processes were being collected and evaluated. The Paris school initiated the use of simple statistics to assess the outcomes of patient management, and nothing was taken on faith—all therapies were open to doubt until proven to be effective by collection and thoughtful interpretation of numerical data. By the 1860s the primary destination for the European-bound American physician-in-training shifted from France to Germany and Austria. Vienna was the center of attention due to the large numbers of patients who were available for study in large hospitals. Opportunities abounded for intensive clinical experience and education in pathological anatomy. The German method, based in laboratory science, was more actively investigative and dynamic than the French approach; compared to the aggressive therapeutic orientation of American medicine, the German medical system was more intensely focused on pathophysiology (the study of the underlying basis of disease).

THE IMPACT AND UNDERSTANDING OF INFECTIOUS DISEASE

In the early nineteenth century, infections such as typhoid fever, cholera, and scarlet fever were commonplace causes of death, but the cause of these illnesses was not understood. (The impact of infection became evident during the Civil War; more deaths among the war's 620,000 casualties could be attributed to disease than to battle.) As the century progressed, important medical advances were made by the observations of individual physicians, and infectious diseases were among the earliest disorders to be understood as distinct disease processes. Even before the microbial basis of infection was understood, the Hungarian physician Ignaz Semmelweis (1818–1865) demonstrated the benefit of hand washing in prevention of the spread of disease; he observed that there was a 12 percent rate of fatal postpartum infection in the patients of his medical colleagues (who did not wash their hands between performing autopsies and delivering babies), compared to the 3 percent rate for midwives (who did not perform autopsies). Semmelweis's observations made it clear that doctors were obviously spreading diseases from cadavers to living patients. By the end of the nineteenth century, the germ theory had become well established due to the work of Louis Pasteur (1822–1895), Robert Koch (1843–1910), and others. With the advent of the twentieth century, medicine was becoming a scientific enterprise, and the basis of epidemics had become far better understood.

An epidemic is an outbreak of disease in which large numbers of people are affected at the same time. Epidemics have recurred throughout the history of mankind and have had a profound influence on life, civilization, and culture. The bubonic plague or "black plague" of the Middle Ages had a devastating effect on European civilization, killing about 60 million people. Fleas carried on infected rats were responsible for the spread of the plague, but in the final analysis it was the crowded conditions and poor sanitation of European cities that contributed to the widespread devastation of the disease. Populations with ongoing exposure to specific infections are able to develop an immunity that promotes their survival, but the introduction of the same disease can be deadly to a population that has never been exposed before; when European explorers brought "new" infections such as smallpox to the New World, native populations were decimated. The influenza epidemic of 1918–1919 had worldwide repercussions due to its high mortality rate. Life in the late twentieth and early twenty-first centuries has been profoundly affected by the AIDS epidemic, not only in areas such as Africa, where the mortality has been overwhelming, but also in Western nations, where rate of infection is influenced by socioeconomic status and where social stigma has been one of many factors creating challenges in controlling the infection.

For the American of the late 1800s, the infections to be feared the most included yellow fever, scarlet fever, cholera, typhoid fever, smallpox, and tuberculosis.

YELLOW FEVER

Yellow fever, one of the more frightful epidemic diseases of the nineteenth century, has striking features that led to its accurate description even before many other infectious illnesses could be characterized. Yellow fever is an acute viral illness that is transmitted by the bite of a mosquito. (Both the yellow fever virus and its Aedes aegypti mosquito vector were believed to have been imported from Africa as a side effect of the slave trade.) Within a few days of the insect bite, yellow fever victims develop fever, body aches, headache, nausea, and severe weakness. Liver damage causes the jaundice that gives the disease its name, and bleeding from the gastrointestinal tract commonly follows (at times associated with profuse vomiting of dark blood). The yellow fever death rate in the nineteenth century ranged from 15 to 50 percent. Because of its mosquito vector, yellow fever was predominantly a summertime disease. It was particularly prevalent in American coastal cities from Galveston, Texas, to Baltimore, Maryland; the virus and the vector and the victims all traveled together on the ships that traveled from port to port. Epidemics of yellow fever were recurrent throughout the nineteenth century. New Orleans was the epicenter of infection and always had at least a few cases in the best of years. In 1847 there were 2,259 yellow fever deaths in New Orleans, and 9,000 people (9 percent of the city's population) died from the disease in 1853. The Mississippi River was a conduit that permitted the infection to migrate from its coastal origins and travel upstream by steamship, and severe outbreaks occurred in Vicksburg, Mississippi, and Memphis, Tennessee. In Life on the Mississippi (1883), Mark Twain (Samuel Langhorne Clemens, 1835–1910) recalled "a desolating visitation of the yellow-fever" in Memphis, where "the people were swept off by hundreds, by thousands; and so great was the reduction caused by flight and by death together, that the population was diminished three-fourths, and so remained for a time" (p. 321). Memphis had been devastated by yellow fever epidemics in 1873 (when nearly 4,000 people died) and again in 1878 (when there were over 5,000 deaths, representing about 10 percent of the city's population).

MARK TWAIN: THE FEAR OF SCARLET FEVER

The severe apprehension associated with a scarlet fever infection is evident in Tom Sawyer's Conspiracy, an unfinished short novel that Mark Twain began to write in 1897. Tom Sawyer tries to catch measles from his friend Joe Harper, but Joe's diagnosis is incorrect, and Tom comes down with scarlet fever instead: "the doctor found it warn't measles at all, but scarlet fever. When aunt Polly heard it she turned that white she couldn't get her breath, and was that weak she couldn't see her hand before her face, and if they hadn't grabbed her she would have fell. And it just made a panic in the town, too, and there wasn't a woman that had children but was scared out of her life" (Tom Sawyer's Conspiracy, p. 186).

Twain considered scarlet fever to be one of the worst illnesses that could be transmitted from one person to another. In Life on the Mississippi, he used the disease as a metaphor for the injury that can be innocently and unknowingly inflicted by a well-intentioned but ultimately harmful ally, a person who "is like your family physician, who comes and cures the mumps, and leaves the scarlet fever behind" (p. 309). When the son of his friend William Dean Howells contracted scarlet fever, Clemens wrote a letter to Howells in January 1884 that empathized with Howells's plight: "The scarlet fever, once domesticated, is a permanent member of the family. Money may desert you, friends forsake you, enemies grow indifferent to you, but the scarlet fever will be true to you, through thick and thin, till you be all saved or damned, down to the last one. I say these things to cheer you. The bare suggestion of scarlet fever in the family makes me shudder" (Mark Twain's Letters 2:439).

SCARLET FEVER

Scarlet fever was another contagious illness that could be identified with reasonable accuracy by nineteenth century physicians and patients even before its causative bacterial agent was identified. Infection with scarlet fever gives rise to a unique rash that is the basis of the infection's name. The rash is the result of a specific toxin that is produced by an underlying bacterial infection with Streptococcus organisms. Bacteriology was in its infancy in the nineteenth century, but Americans lived in fear of scarlet fever epidemics long before its causative organism was isolated from human tissue in 1874. The Streptococcus is widely distributed in nature and is capable of causing infection in a variety of tissues. Although infections with the Streptococcus organism are now generally regarded as being relatively benign, with fairly innocuous skin infections and "strep throat" being among the more common illnesses that result from streptococcal infections, this was not the case prior to the development of effective antibiotics in the mid-twentieth century. Until, then, streptococcal infections could be devastating and life threatening (and it seemed as though the streptococcal infections associated with scarlet fever were particularly deadly). Parents were terrorized by the infection for good reason. The victims were commonly children; in the last half of the nineteenth century, twothirds of deaths from scarlet fever occurred in children under the age of five years. For Americans in the 1800s, an outbreak of scarlet fever generated a fear that rivaled the dread associated with epidemics of cholera and plague.

CHOLERA

Cholera was another highly feared disease of the era. This very contagious bacterial infection of the intestinal tract caused severe diarrhea, dehydration, and, very often, death. Cholera was an annual visitor that traveled up the Mississippi River every spring, carrying with it a high risk of mortality for anyone afflicted with the disease. It was more common and far more deadly than any other infection. Nothing else created such a sense of panic as the arrival of cholera, and the risk of becoming infected with the cholera bacterium loomed as an overwhelming worry for anyone who lived near the river. Every year, the infection appeared to originate in New Orleans in the spring and then spread northward up the Mississippi through the summer months. The disease shared the same routes that were favored by yellow fever as it moved from one port to the next, carried by the steamboat traffic. The 1849 cholera death toll was devastating. In St. Louis there were 4,557 deaths from cholera during the year, compared to 4,046 deaths from all other diseases combined. In the month of July alone, there were 1,895 cholera deaths from the city's total population of 50,000.

The medical profession's first obstacle in dealing with cholera came from its ignorance of the disease's cause. As with the other serious infections of the nineteenth century, cholera epidemics created overwhelming health problems long before cholera's infectious nature was demonstrated. In the medical thinking of the era, disease in general was not attributable to specific causative factors but instead was believed to be the result of poorly defined interactions between the personal characteristics of each patient and vague environmental factors. A highly regarded nineteenth-century St. Louis physician and professor of therapeutics at the Missouri Medical College, Dr. William McPheeters, believed that the only real hope of eradicating cholera would be "the withdrawal of the peculiar unknown atmospheric poison which has always given rise to it" (McPheeters, p. 81). Because the disease seemed to be most rampant in the parts of St. Louis that were the dampest, dirtiest, and most crowded, hygienic approaches were initiated whenever cholera struck. In addition to the general cleaning of the city, "bonfires were nightly built in nearly every street and the whole city repeatedly fumigated with tar and sulphur" (p. 81), an approach that undoubtedly created a scene of ghastly smoky terror throughout the city and did nothing to reassure the minds of the fainthearted. When the 1849 outbreak finally subsided late in the year, McPheeters noted that the general level of health in St. Louis had become remarkably good, and in keeping with the concept of an environmental (rather that a bacteriological) basis for the epidemic, he suggested that "once the storm of disease had subsided the atmosphere seemed to be purified by its fury and rendered fitter for respiration" (pp. 83–84).

TYPHOID FEVER

Typhoid fever, also referred to as enteric fever, was another important contagious disease of the late nineteenth and early twentieth centuries. The disease is caused by an infection with Salmonella bacteria and transmitted through direct contact with an infected individual or through ingestion of contaminated food. Person-to-person spread is a particularly important mechanism of dissemination of the illness, as demonstrated by the case of "typhoid Mary," a cook in the early twentieth century who spread infection to approximately fifty other people. Typhoid fever is usually associated with high fever, abdominal pain, and enlargement of the liver and spleen. Other features can include diarrhea, a typical rash that is characterized by "rose spots," and neuropsychiatric features that can include confusion or delirium. As was the case with scarlet fever, the typical features of typhoid fever permitted accurate recognition of the disease even before its specific bacteriological cause was pinned down. Before the era of antibiotics, the death rate from typhoid fever was around 15 percent; the survivors commonly suffered a prolonged illness that lasted for weeks, with an interval of debilitation that could last for months.

Infectious diseases, especially those with a lingering course and significant mortality, became popular subjects for writers wishing to deal with topics of mortality, justice, suffering, anguish, and ethical dilemmas. For example, Samuel Clemens used his personal experiences with typhoid fever in a story first published in the December 1902 issue of Harper's. In "Was It Heaven? Or Hell?" Clemens addressed the ethical question of whether a physician should lie to a patient in order to give the patient hope. In order to write this story, Clemens needed a disease that was contagious, ran a prolonged course, and was associated with a fairly high death rate. Typhoid fever was the perfect disease for the story. Clemens first became familiar with the details of infection with typhoid fever when his wife Livy developed the illness in 1871. The Clemens household had initially been exposed to the disease in 1870 when Emma Nye, an old school friend of Livy's, came down with typhoid fever during a visit. Sam and Livy Clemens nursed Nye through her prolonged illness and thus observed every terrible feature of the infection firsthand. In a letter written in September 1870, Clemens lamented that "poor little Emma Nye lies in our bed-chamber fighting wordy battles with the phantoms of delirium. . . . The disease is a consuming fever—of a typhoid type. . . . the poor girl is dangerously ill" (Mark Twain's Letters 4:191). The Clemens family watched Nye's gradual and miserable death from the devastating illness, and there is no doubt that the anxiety in their household was extreme in February 1871 when Livy Clemens developed high fever and "rose spots" on her abdomen and was diagnosed with typhoid fever. She required around-the-clock nursing, and it was not until mid-March that she was even able to get out of bed and walk with assistance. Even as Livy appeared to be recovering from her own battle with typhoid, Clemens had guarded optimism about the likelihood of her recovery, and his worry was intense: "Livy is very, very slowly & slightly improving, but it is not possible to say whether she is out of danger or not—but we all consider that she is not" (4:334–335). The weariness created by the prolonged illness pushed Clemens to his emotional limits, and his writing productivity came to a standstill: "I am still nursing Livy night & day & cannot write anything. I am nearly worn out. . . . I have been through 30 days' terrific siege" (p. 341).

Clemens's memories of typhoid fever were clear in his mind thirty-one years later, when he wrote "Was It Heaven? Or Hell?" His fictional account is centered on a woman, Margaret Lester, who is restricted to her sickroom as she is dying of typhoid fever. When her sixteen-year-old daughter Helen tells an innocent lie, the woman's overly righteous aunts Hannah and Hester Gray force the girl to confess her moral transgression face-to-face to her contagious mother, in spite of the family physician's order that the mother must be kept in isolation. The doctor is angered when he finds out that the girl was unnecessarily exposed to the mother's infection for such a trifling reason, and he is further enraged when the aunts rationalize their action through their rigid advocacy of truth-telling at all costs. Through the physician's retort to the aunts, Clemens makes clear his own position that a rigid commitment to the absolute truth is not always compatible with the role of the physician as healer:

The doctor glowered upon the woman a moment, and seemed to be trying to work up in his mind an understanding of a wholly incomprehensible proposition; then he stormed out:

"She told a lie! Did she? God bless my soul! I tell a million a day! And so does every doctor." ("Was It Heaven? or Hell?" p. 78)

The aunts initially remain steadfast in their belief that all lies are sinful, even as the physician argues that purposeful lying may be anything but a sin. As a result of the unnecessary exposure to her mother's typhoid fever, Helen herself contracts the illness and dies. At first the aunts feel compelled to maintain their commitment to the truth, and they fully intend to tell the dying woman that her daughter has preceded her in death. When they realize that this truth will bring profound despair to the dying woman, the aunts find themselves reversing their own strongly held moral position, and they proceed to invent a series of lies that spares the girl's mother from learning of the girl's death. As a result of their compassionate decision, the woman goes to her grave with the mistaken belief that her beloved daughter is still alive and well. Samuel Clemens ends the story with the rhetorical question posed in its title: "Was It Heaven? Or Hell?"

SMALLPOX

Smallpox was another contagious, deadly, and highly feared disease of the nineteenth century, as evidenced by a letter written by Samuel Clemens to his wife, Livy, in 1871. "Get vaccinated—right away—no matter if you were vaccinated 6 months ago. . . . Small pox is everywhere—doctors think it will become an epidemic" (Mark Twain's Letters 4:521). For Clemens, the disease apparently was everywhere, and smallpox appeared in The Innocents Abroad (1869), Roughing It (1872), Adventures of Huckleberry Finn (1885), A Connecticut Yankee in King Arthur's Court (1889), and Following the Equator (1897).

Advances in medicine such as vaccines against life-threatening diseases were among the benefits of the newly developing medical science of the era. However, medical advances often have political and social repercussions. In his role as a champion of the powerless and disenfranchised, Clemens was aware that the limitations in knowledge, sophistication, and financial resources of recent immigrants made them potential victims of a medical care system that could create obstacles as frustrating and baffling as those produced by any other bureaucratic structure. Physicians were taking advantage of immigrants by enforcing a requirement for universal vaccination while charging exorbitant fees. The year before he exhorted his wife to get vaccinated against smallpox, Clemens protested the vaccination policies of unscrupulous physicians and uninformed lawmakers in "Goldsmith's Friend Abroad Again" (1870), a series of fictional letters written by a recent Chinese immigrant:

he said, wait a minute—I must be vaccinated to prevent my taking the small-pox. I smiled and said I had already had the small-pox, as he could see by the marks, and so I need not wait to be "vaccinated," as he called it. But he said it was the law, and I must be vaccinated anyhow. The doctor would never let me pass, for the law obliged him to vaccinate all Chinamen and charge them ten dollars apiece for it, and I might be sure that no doctor who would be the servant of that law would let a fee slip through his fingers to accommodate any absurd fool who had seen fit to have the disease in some other country. And presently the doctor came and did his work and took my last penny—my ten dollars which were the hard savings of nearly a year and a half of labor and privation. Ah, if the law-makers had only known there were plenty of doctors in the city glad of a chance to vaccinate people for a dollar or two, they would never have put the price up so high against a poor friendless Irish, or Italian, or Chinese pauper fleeing to the good land to escape hunger and hard times. (P. 135)

TUBERCULOSIS

As the nineteenth century gave way to the twentieth, the specters of scarlet fever, typhoid fever, yellow fever, and cholera were replaced by a different, but equally frightening, infection—tuberculosis. Tuberculosis, also referred to as "consumption" due to the slow wasting death of its victims, has historically been associated with increases in population density, and it became increasingly common with the spread of industrialization. Tuberculosis became the leading infectious cause of death in the United States between the 1860s and the 1940s, accounting for one out of seven deaths. The seventeenth-century religious writer John Bunyan (1628–1688) called it the "captain of all these men of death" in The Life and Death of Mr. Badman (1680). In 1861 Oliver Wendell Holmes (1809–1894) characterized tuberculosis as "the white plague." Tuberculosis has often been romanticized in literature—perhaps to a greater extent than any other infection—because of its prolonged, lingering, wasting course. Patients who are slowly dying of "consumption" have ample opportunities for moral reflection and inspirational suffering as they serve as emblems of human mortality. Tuberculosis has been associated with being the disease of the brilliant and the talented, and its victims included the Brontës, Frédéric Chopin, Anton Chekov, John Keats, and Niccoló Paganini. Before Robert Koch's identification of the causative bacterium in 1882 confirmed that tuberculosis was an infectious disease, social critics (in keeping with the medical concepts of the times) took a moralistic tone and associated the illness with the vices of an accelerated urban lifestyle; those who were most licentious in their use of alcohol or in their sexual conduct were thought to be at greatest risk for the disease. In the pre-antibiotic era, treatment by removal of the patient into a healthy environment was the preferred approach, and Thomas Mann's novel The Magic Mountain (begun in 1912 but not published until 1924) exemplifies the thinking of the times by linking social and emotional factors with the disease.

OTHER INFECTIONS AND EPIDEMICS AS LITERARY METAPHOR

Henry James's 1878 novella, Daisy Miller: A Study, employs a fatal infection with malaria (rather than tuberculosis) as a metaphor for the protagonist's loose moral standards. The scope of this type of metaphor, linking disease and behavior, is made even broader—encompassing not just the individual, but the entire social framework—in Jack London's novel The Scarlet Plague (1915). This science fiction story describes the aftermath of a new plague in the year 2013 which has killed most of the world's population. Social structures collapse and civilization is destroyed as a result of the plague, and society is set back to a primitive and nomadic existence. The novel demonstrated London's interest in the mysteries of microbiology, but its most important feature was the use of the epidemic to cause social disruption and give London an opportunity to criticize modern social structure.

Infections and epidemics are also major themes in Sinclair Lewis's 1925 novel Arrowsmith. The protagonist, Martin Arrowsmith, is a young physician who worships the pure science of his bacteriology professor but then makes the choice to pursue private practice. He is forced to leave his medical practice after misdiagnosing a case of smallpox. He then shifts to a career in public health and discovers a cure for bubonic plague. He hopes to test it scientifically, only to have his wife die of the infection. As a physician, Arrowsmith is torn between his desires of making money, treating illness, or pursuing scientific truth.

For Sinclair Lewis and Jack London, as with Samuel Clemens before them, infections and epidemics were metaphors for the catastrophes and injustices of life. The use of such diseases in literature creates an effective mechanism for exploring the behaviors of an individual or the values of a society.

See alsoHealth and Medicine; Pseudoscience

BIBLIOGRAPHY

Primary Works

London, Jack. The Scarlet Plague. New York: Macmillan, 1915.

Twain, Mark. "Goldsmith's Friend Abroad Again." In A Pen Warmed-Up in Hell: Mark Twain in Protest, edited by Frederick Anderson, pp. 131–152. New York: Harper Colophon, 1972.

Twain, Mark. Life on the Mississippi. Boston: James R. Osgood and Company, 1883.

Twain, Mark. Mark Twain's Letters. Vol. 2, 1867–1868. Edited by Alfred Bigelow Paine. New York: Harper & Brothers, 1917.

Twain, Mark. Mark Twain's Letters. Vol. 4, 1870–1871, edited by Victor Fischer, Michael B. Frank, and Lin Salamo. Berkeley: University of California Press, 1995.

Twain, Mark. Tom Sawyer's Conspiracy. In Mark Twain's Hannibal, Huck & Tom, edited by Walter Blair. Berkeley: University of California Press, 1969.

Twain, Mark. "Was It Heaven? or Hell?" In his The $30,000 Bequest and Other Stories. New York: Harper & Brothers, 1906.

Secondary Works

Duncan, C. J., S. R. Duncan, and S. Scott, "The Dynamics of Scarlet Fever Epidemics in England and Wales in the Nineteenth Century." Epidemiology and Infection 117 (1996): 493–499.

Gray, Barry M. "Streptococcal Infections." In Bacterial Infections of Humans: Epidemiology and Control, 3rd ed., edited by Alfred S. Evans and Philip S. Brachman, pp. 673–711. New York: Plenum, 1998.

Greenwood, Ronald D. "An Account of a Scarlatina Epidemic, 1839." Illinois Medical Journal 150 (1976): 147–148.

Hornick, R. B., S. E. Greisman, T. E. Woodward, H. L. DuPont, A. T. Dawkins, and M. J. Snyder. "Typhoid Fever: Pathogenesis and Immunologic Control." New England Journal of Medicine 283 (1970): 686–691.

Keiger, Dale. "Why Metaphor Matters." Johns Hopkins Magazine, February 1998. Available at http://www.jhu.edu/∼jhumag/0298web/metaphor.html.

McPheeters, William M. "Epidemic of Cholera in St. Louis in 1849." In A History of Medicine in Missouri, edited by E. J. Goodwin, pp. 71–92. St. Louis: W. L. Smith, 1905.

Ober, K. Patrick. Mark Twain and Medicine: "Any Mummery Will Cure." Columbia: University of Missouri Press, 2003.

Patterson, K. David. "Yellow Fever Epidemics and Mortality in the United States, 1693–1905." Social Science and Medicine 34 (1992): 855–865.

Rosenberg, Charles E. "The Therapeutic Revolution: Medicine, Meaning, and Social Change in Nineteenth-Century America." In his Explaining Epidemics: And Other Studies in the History of Medicine, pp. 9–31. New York: Cambridge University Press, 1992.

Turco, Jenifer, and Melanie Byrd. "An Interdisciplinary Perspective: Infectious Diseases and History." American Biology Teacher 63, no. 5 (2001): 325–335.

Warner, John Harley. The Therapeutic Perspective: Medical Practice, Knowledge, and Identity in America, 1820–1885. Princeton, N.J.: Princeton University Press, 1997.

K. Patrick Ober