Historical Perspectives On Contemporary Issues
Sickness and the City
A forum held at the New York Academy of Medicine on October 24, 2018, and continued online here.
Billy G. Smith is Distinguished Professor of Letters and Science in the History Department of Montana State University, where he has won every major teaching and research award offered. He is the author or editor of eight books and dozens of articles. He lives in Bozeman, MT.
Julia Mansfield is the Cassius M. Clay Postdoctoral Associate in History at Yale University. She holds a B.A. from Harvard College and a Ph.D. from Stanford University. From 2014-17, she was a Fellow-in-Residence at the Consortium for History of Science, Technology, and Medicine, and she held a Dissertation Writing Fellowship in 2013-14. She is currently writing a book on the history of yellow fever in the United States.
In December 2015, yellow fever emerged in Angola. The outbreak alarmed global health experts, who worried that yellow fever might travel across sub-Saharan Africa and even spread beyond the continent. The World Health Organization (WHO) monitored the outbreak closely for six months until it faded away. While the outbreak did not produce an international crisis, it galvanized global health experts to step up their efforts to control yellow fever in Africa, and the WHO is now poised to launch its most ambitious campaign yet against the disease.See more...
In December 2015, yellow fever emerged in Angola. The outbreak alarmed global health experts, who worried that yellow fever might travel across sub-Saharan Africa and even spread beyond the continent. The World Health Organization (WHO) monitored the outbreak closely for six months until it faded away. While the outbreak did not produce an international crisis, it galvanized global health experts to step up their efforts to control yellow fever in Africa, and the WHO is now poised to launch its most ambitious campaign yet against the disease. This response to the outbreak of 2015/16 springs not only from recent events but also from the long history of yellow fever in the West.
Yellow fever is a viral illness spread by mosquitos. The virus typically cycles between mosquitos and non-human primates in tropical forests and causes little harm, but, occasionally, it spills over to humans and wreaks havoc. One species of mosquito is primarily responsible for transmitting the virus to humans: Aedes aegypti. This is the same mosquito that carries the Zika virus, dengue fever, and Chikungunya. A. aegypti are effective vectors for many human pathogens because they thrive in cities. The mosquitos have adapted well to urban settings because they like to lay their eggs in small catches of water. They can make nurseries out of flower pots, water barrels, and discarded tires. The breeding habits of A. aegypti allow yellow fever to infect densely populated urban spaces.
Yellow fever can kill a person in less than ten days, but it kills selectively. Children and the elderly tend to have mild cases while adults succumb. The disease gets its name from a yellow tinge that spreads across the skin and eyes. This symptom – the effect of liver failure – usually comes with another grisly sign: black vomit. Victims bleed internally in the gut and stomach, which makes them vomit up semi-digested blood. In the worst cases, bleeding spread to other organs, and, just before death, blood erupts from the mouth, nose, ears, and eyes. The victims of yellow fever appear to be “absolutely drowned in their own blood.”
Today, yellow fever crops up sporadically in South America and sub-Saharan Africa, where forest-dwelling monkeys harbor the virus. In the past, its range extended much farther than this. Yellow fever was once common in North America, and it exploded periodically into epidemics that reached southern Europe.
Yellow fever migrated to America from Africa in the 1600s in slaving ships that also brought tens of thousands of enslaved African people across the ocean. By the early 1800s, yellow fever was endemic in the Caribbean islands, and, later, it settled around the rim of the Gulf of Mexico. New Orleans, Havana, Veracruz, and Cartagena were some of its favorite haunts in the nineteenth century. The presence of yellow fever in the port cities of North America threatened the lives of travelers, migrants, sailors, and soldiers passing through them. Moreover, the disease’s presence raised the possibility of a pandemic.
The largest recorded attack of yellow fever happened around 1800 when an outbreak spilled over from the Caribbean to the United States, Spain, and Italy. This pandemic began in 1793 and lasted twelve years. It coincided with the French Revolutionary Wars, the Napoleonic Wars, and the Haitian Revolution, which dislodged tens of thousands of people from the Caribbean and created the first refugee crisis in American history. Movements of troops and refugees combined with shipping traffic dispersed yellow fever around the North Atlantic. The pandemic hit every major port in the United States including Boston, New York, Philadelphia, Baltimore, and Charleston. It also reached the coast of Europe, where it surfaced in Cadiz, Seville, Malaga, Valencia, and finally, Livorno. Death tolls varied greatly. For example, yellow fever killed 7,293 people (approximately ten percent of the population) when it reached Cadiz in 1800. When it reached Livorno in 1804, yellow fever killed only seven hundred people. This pandemic awoke people in Europe and the United States to the risk of infection by yellow fever and spurred the first efforts to curb that threat.
Over the course of the late nineteenth and early twentieth century, officials were able to drive yellow fever out of North America through mosquito eradication. Their success led to campaigns with a longer reach, and these continue today. In South America, local governments direct the campaign against yellow fever now and rely mainly on mosquito control. In Africa, a different strategy prevails: vaccination. Scientists developed a vaccine for yellow fever in the 1930s with support from the Rockefeller Foundation. After this breakthrough, the Rockefeller Foundation partnered with France to distribute the vaccine in French West Africa. This partnership ended in the mid-twentieth century, and, a bit later, France’s colonies broke away, so the vaccination campaign halted for a while. But the WHO revived it in 2006. For more than a decade, the WHO has led efforts to vaccinate communities in Africa believed to be at high risk based on historical incidence of yellow fever. Historical data did not, however, prepare anyone for an outbreak in Angola.
The outbreak in Angola erupted in December 2015, which was the middle of the rainy season. Moisture makes the eggs of Aedes aegypti hatch, so mosquitos were abundant and available to spread yellow fever. The outbreak likely emerged from the forests of southern Angola, but it did not get doctors’ attention until it reached the capital city, Luanda. Once doctors detected the outbreak, they found cases of yellow fever across the country. The outbreak grew for six weeks reaching a peak in February; then, it started to decline. Overall, the WHO learned about 879 cases with 119 deaths. These figures represent a low estimate of infection and mortality. Some observers estimate that the outbreak was much larger perhaps even twice as large as the reported figures allow. The outbreak of 2015/16 not only exposed a shortcoming in the WHO campaign against yellow fever, it also raised the specter of international contagion.
During the outbreak, global health experts worried about the risk of the epidemic spreading abroad. The WHO took this risk seriously and issued a warning in April 2016 about the danger of international contagion. The primary basis for these fears was the trend in economic growth underway in sub-Saharan Africa. Angola exemplifies this trend. Oil production has fueled urban expansion and infrastructure development in Angola, which is now the second largest oil exporting country in Africa. The capital city, Luanda, is growing rapidly becoming a choice destination in sub-Saharan Africa for migrant laborers and cosmopolitan businessmen. The local airport offers direct flights to cities in Asia, Europe, and the Americas. An equally dense web of transit routes links the capital to outlying provinces in Angola. These corollaries of economic growth heighten the risk that yellow fever – once unleashed – could spread widely.
Corridors of travel are not the only risk factor for the spread of yellow fever. Another risk factor is the prevalence of A. aegypti around the globe. Eradication efforts cut down the population of A. aegypti in North and South America during the twentieth century, but the mosquitos have rebounded. A. aegypti can be found buzzing across the southern United States from California to Florida. Their range extends north to Washington, D.C. and covers most of Central America and half of South America. A. aegypti live in Australia and Southeast Asia too. Since A. aegypti live on multiple continents and thrive in populous cities, they have the potential to carry an epidemic around the globe.
The spread of Zika virus from Oceania to Brazil in 2016 showed this danger. In contrast to Zika, the outbreak of yellow fever in Angola did not cross continents. Infected travelers flew from Angola to China, but yellow fever did not spill over to Asia. This result might have allayed concern about yellow fever if Zika had not – almost simultaneously – crossed the Pacific Ocean. The example of Zika – which is also spread by A. aegypti – intensified worry about a multi-continent epidemic of yellow fever. In summary, the resurgence of A. aegypti, economic development in sub-Saharan Africa, and the trajectory of Zika have convinced global health experts to re-think their approach to yellow fever.
Since 2016 the WHO has developed a strategy to curb the threat of yellow fever. The Global Strategy to Eliminate Yellow Fever Epidemics (EYE) “aims at ensuring universal access to yellow fever immunization so that each and every person in yellow fever at-risk countries is protected against the disease.” This objective aligns with the WHO’s long-term goal of improving public health around the globe, but it is urgent today – the WHO explains – because yellow fever is “a significant threat to global health security, with the potential to turn into a public health emergency of international concern.” In these words, warnings from the late 1700s seem to echo across the centuries, and yellow fever once again serves to represent the nexus of global trade, migration, and contagion.
Urmi Engineer Willoughby, Yellow Fever, Race, and Ecology in Nineteenth-Century New Orleans (Baton Rouge: Louisiana University Press, 2017)
Alan D. T. Barrett and Stephen Higgs, “Yellow Fever: A Disease that Has Yet to Be Conquered,” Annual Review of Entomology 52 (2007): 209-29
Alan D. T. Barrett and Thomas P. Monath, “Epidemiology and Ecology of Yellow Fever Virus,” Advanced Virus Research 61 (2003): 291-315
Brett R. Ellis and Alan D.T. Barrett, “The Enigma of Yellow Fever in East Africa,” Reviews in Medical Virology 18 (2008): 331-46
Paul Reiter, “Climate Change and Mosquito-Borne Disease,” Environmental Health Perspectives 109 (2001): 141-61
Emily S Jentes, Gilles Poumerol, Mark D Gershman, et al., “The Revised global yellow fever risk map and recommendations for vaccination, 2010: consensus of the Informal WHO Working Group on Geographic Risk for Yellow Fever,” Lancet Infect Dis 11 (August 2011): 622-632
 World Health Organization, “Eliminating Yellow Fever Epidemics (EYE) Strategy: Meeting demand for yellow fever vaccines,” January 29, 2018, https://www.who.int/csr/disease/yellowfev/meeting-demand-for-vaccines/en/
 Thomas Phipps Howard, The Haitian Journal of Lieutenant Howard, York Hussars, 1796-1798, ed. Roger Norman Buckley (Knoxville, TN: University of Tennessee Press, 1985), 49-50.
 James Fellowes, Reports of the Pestilential Disorder of Andalusia, which appeared at Cadiz in the Years 1800, 1804, 1810, and 1813 (London 1815), 50.
 “Medical & Philosophical News: Domestic,” The Medical Repository 2 (April 1805): 425
 Arran Hamlet, Kevin Jean, William Perea, et al., “The Seasonal Influence of Climate and Environment on Yellow Fever Transmission Across Africa,” PLoS Negl Trop Dis 12 (3): March 2018 doi: 10.1371/journal.pntd.0006284
 World Health Organization, “Yellow Fever Outbreak in Angola: Situation Report W29,” July 24, 2016
 “Angola Faces Health Crisis as Oil Price Drop Leads to Cutbacks,” Voice of America, Feb. 11, 2016. https://www.voanews.com/a/angola-faces-health-crisis-as-oil-price-drop-l...
 Moritz U.G, Kraemer et al., “The global distribution of the arbovirus vectors Aedes aegypti and Ae. Albopictus,” Elife 4 (2015) e08347; Micah Hahn et al., “Reported distribution of Aedes (Stegomyia) aegypti and Aedes (Stegomyia) albopictus in the United States, 1995-2016,” Journal of Medical Entomology 53 (5): 1169-1175
 World Health Organization, “The EYE Strategy addresses three important global health agendas.” https://www.who.int/csr/disease/yellowfev/eye-strategy-and-global-agenda...
Kathryn Olivarius is a historian of nineteenth-century America, interested primarily in the antebellum South, Greater Caribbean, slavery, and disease. Her research seeks to understand how epidemic yellow fever disrupted Deep Southern society.
In describing how disease shaped Atlantic empires in the eighteenth- and nineteenth-centuries, historian J. R. McNeill wrote, it is “perhaps a rude blow to the amour proper of our species to think that lowly mosquitoes and mindless viruses can shape our international affairs. But they can.” In their presentations for the recent symposium Sickness and the City, Montana State University historian Billy Smith and University of Pennsylvania epidemiologist Michael Levy suggest these words echo across the ages.See more...
In describing how disease shaped Atlantic empires in the eighteenth- and nineteenth-centuries, historian J. R. McNeill wrote, it is “perhaps a rude blow to the amour proper of our species to think that lowly mosquitoes and mindless viruses can shape our international affairs. But they can.” In their presentations for the recent symposium Sickness and the City, Montana State University historian Billy Smith and University of Pennsylvania epidemiologist Michael Levy suggest these words echo across the ages. Bugs have profoundly impacted, and impact still, human affairs on both personal and geopolitical scales.
On their face, the 1793 yellow fever epidemic in Philadelphia and modern-day Chagas disease in Peru are very different. Their sites are thousands of miles apart and these outbreaks took place in vastly different chronological, ethnic, and medical contexts. Therefore, they had/have profoundly different social meanings and impacts. Yellow fever and Chagas also have different insect vectors. But taken together, these outbreaks pose questions about urbanization, epidemiology, disease mapping, and the role of the state and science in mediating sickness.
As an historian of yellow fever, primarily in the nineteenth-century Greater Caribbean and New Orleans, I have long been familiar with Professor Billy Smith’s work. His 2013 tour-de-force Ship of Death: A Voyage that Changed the Atlantic World (Yale University Press) tracked the macabre journey of the Hankey, a British ship that unknowingly spreading yellow fever—perhaps the most fearsome disease in the Atlantic World at the time—from Bolama Island off West Africa to first Barbados, Grenada, and Haiti and then to Philadelphia. Within four days of the Hankey’s August 1793 arrival in Pennsylvania, the Aedes aegypti mosquitos hiding out and breeding in the ship’s freshwater caskets had fanned out from the docks, triggering multiple outbreaks of yellow fever. By November, when the first mosquito-killing frosts descended, more than 5,000 people had died, about 10 percent of Philadelphia’s population. This would be akin to New York City losing about one million inhabitants today. Flight from the city exacerbated the disease’s depopulation effect: 17,000 people—including George Washington, Thomas Jefferson, and most of the political elite—evacuated. Imagine one third of New York City, or the entire population of Brooklyn and Staten Island, making a frantic, terrified exodus. Those that remained—either by choice, a sense of duty, or because they were too poor to go—faced the prospect that they would die horribly, writhing in a pool of their own bloody vomit.
Professor Michael Levy described a less dramatic, though no less important, tale: the decades-long effort to control Chagas disease in contemporary Peru. Chagas disease impacts between 5 and 20 million people worldwide, who are infected after being bitten and defecated on by the Triatoma infestans. Between 20 and 30 percent of those affected will develop the determinate form of the disease, causing various health problems, particularly in the cardiac and digestive systems. A small percentage develop an acute case which can be life threatening. Through various efforts to control the vector population—chiefly spraying houses with deltamethrin—transmission has been largely controlled in Uruguay, Chile, Brazil, and most of Paraguay. The bug remains in Bolivia, Northern Argentina, parts of Paraguay, and Southern Peru, where this historically rural disease has become increasingly urban. Since 2001, the Peruvian Ministry of Health, with funding from the Canadian government, has conducted an insecticide campaign in Arequipa. They have treated about 70,000 houses, and the bug is now essentially gone. But it can reemerge. Levy’s team has followed the health ministry, mapping the patterns of transmission and infection.
Levy’s work in tracking Chagas disease provides various lessons for historians and scientists alike. First and foremost, epidemiology is (and always has been) incremental and frustrating. There are essentially no silver bullets, fast cures, or easy fixes. Bugs are as elusive as they are “smart” – they adapt, disappear, and reemerge – a process complicated by climate change, migration, human politics, and urbanization. But determination and the ability to map, quantify, and adjust bears fruit. Controlling Chagas disease has been one of the greatest public health triumphs of the last twenty to thirty years, just as eradicating smallpox was in an earlier generation, or creating an effective vaccine against yellow fever was at the turn of the twentieth century. These triumphs are seldom celebrated in Hollywood movies (though I would pay good money to see lingering shots of Ryan Gosling squeezing poop out of a triotomine bug), but they have radically impacted the way we live, the way we die, what we fear, how we plan for the future, how we travel, not to mention the relationship between state and citizen, and our relationships with one another. Health and sickness have always been political and personal, shaping our identities and prospects in ways we seldom pause to recognize.
This is true historically, too. We know a great deal more about disease now than Benjamin Rush, Absalom Jones, Richard Allen, and Anne Saville did in the 1790s. And it can be extremely frustrating—two centuries of epidemiological advancement later—to see historical actors make choices that we would now consider obviously dangerous and misguided. (How could a Philadelphia merchant in good-conscious have argued against the efficacy of quarantines in stemming yellow fever?) But the historian’s job is to reconstruct events and to understand—and not judge—historical actors operating in a world without germ theory, the concept of viruses, or a robust definition of contagion.
Facing an invisible, terrifying, and seemingly intractable microbial world, Philadelphia’s inhabitants—black and white, male and female, medically-trained and lay—used this occasion to express other anxieties. Yellow fever became a Susan Sontag-like metaphor for society-writ-large. In its aftermath, as Smith details, screeds about the role of physicians, politicians, and businessmen were printed. Many argued that the poor—the group always hit the hardest—had brought the disease on themselves with their filthiness and dissipation. Some questioned whether living in pestilential cities was wise; if pestilence was God’s punishment. Still others asked what was more important: individual and commercial freedom, or the states prerogative to enact quarantine.
Most of all, there was an outpouring of racist rhetoric—exemplified by physician Matthew Carey—during and after the epidemic. This would appear to be a strange reaction in light of events. Philadelphia’s free black population, led by Absalom Jones and Richard Allen, was at the forefront of care during the yellow fever epidemic, doing the thankless work of guarding the city against crime and looters, nursing the sick and convalescent, and carting and burying bodies. As cases started to appear in August, Benjamin Rush had implored the city’s free black population to remain because he—like almost every person in the larger American/European medical community—believed black people were naturally immune or resistant to yellow fever. Rush famously changed his mind on this topic, but it was too late – over 240 black people died from yellow fever during the epidemic. Rather than being thanked, free black people were treated mostly with contempt, derided as profiteers and death-entrepreneurs. As Jones wrote the following year, “our services [were] extorted at the peril of our lives, yet you accuse us of extorting a little money from you.”
Though I am uninterested in resurrecting the long-heated and now-settled (I believe) debate about black hereditary resistance to yellow fever, I wonder why the narrative turned into an indictment of black people rather than a celebration. Was this just classic scapegoating? To put a finer point on it: would the Matthew Careys have always found a reason to express their racial animus, but simply seized on this epidemic as the most convenient vehicle? Do these negative reactions show the stark difference between legal freedom and citizenship; of the insurmountable prejudice black people faced in a slave nation, even in free states?
There are other political questions, too. Smith’s amazing (and darkly funny) description that which cure a person took—heroic (purging and bleeding) or passive (bedrest and fluids)—was a statement about one’s party affiliation, shows that health was political and politicized. Did such partisan medical choices trickle down into the general population? Is there a way of accessing those voices, or perhaps triangulating them?
Did this epidemic change Philadelphians’ ideas about the state’s responsibilities regarding health and welfare? It is perhaps easy to indict George Washington and others for fleeing the city, leaving behind (mostly) the poorest and most vulnerable residents to fend for themselves. But what other options were there in 1793? It would be another century until the mosquito vector was discovered, and the prevailing orthodoxy of the time was that escape was the surest remedy. (“Acclimation,” falling sick with and surviving yellow fever guaranteed lifetime immunity, but this was the other and far more dangerous approach).
This was an era, as historian William J. Novak described, where the rights and obligations of the state and citizens were being reconfigured, especially in terms of health, welfare, and education. We now would impeach politicians for fleeing the city or sacrificing thousands of people’s lives to assuage the capitalist elite’s demands to do away with quarantine (or would we?). But my research has shown that this political reaction was the norm for most of the eighteenth and nineteenth centuries, and was not necessarily seen as a dereliction of duty. In New Orleans, for example, politicians did not even feign a desire to remain in the city during the 1853 epidemic that killed nearly 12,000 people (one of the worst natural disasters in American history in mortality terms). New Orleans was starkly different than Philadelphia, which by 1850 had a robust welfare state and public health infrastructure. So, was 1793 a turning point? Can we see this epidemic as both destructive and generative, instilling the population with a new sense of their place in society going forward (based on a strict racial and class-based hierarchy) but also compelling the state to reconsider its night-watchman approach to matters of health?
I’ll end with a final set of questions about the future. Historians are loath to claim that anything is inevitable or overly-determined. But as Smith lays out (and as McNeill does in Mosquito Empires) yellow fever profoundly impacted eighteenth-century diplomacy, colonization schemes, and mercantile networks. (I would also add capitalism itself to that list). Yellow fever strongly steered—if not determined—the course of geopolitics and empires, playing a crucial role in Washington’s victory at Yorktown, in tipping the scales against the French army in St. Domingue, and in prompting Napoleon’s sale of Louisiana to the United States. This in turn triggered the explosion of the Cotton Kingdom, indigenous removal, and westward expansion. Has Chagas disease had a similar, tracible effect? Has it impacted the economic, social, and political trajectories of Peruvians, or of people in other affected nations in South America? Has it controlled migration patterns, what kinds of jobs people take, when/where they decide to have children, or economic markets? What will the total eradication of the Chagas vector mean for the future on both a micro and macro scale?
Both Smith and Levy remind us that sickness has been—and remains still—not just a personal experience, but a matter of statecraft, policy, and international geopolitics. A strong state reaction, undergirded by data and scientific research, is crucial to stemming not just mortality but the malignant social effects wrought by disease-carrying bugs.
 J. R. McNeill, Mosquito Empires: Ecology and War in the Greater Caribbean, 1620-1914 (Cambridge, 2010), 2.
 Billy Smith, Ship of Death: A Voyage that Changed the Atlantic World (New Haven, 2014), 187-93.
 Benjamin Rush, An Account of the Bilious Remitting Yellow Fever, as it Appeared in the City of Philadelphia, in the Year 1793 (Philadelphia, 1794), 97.
 Absalom Jones, A Narrative of the Proceedings of the Black People, During the Late Awful Calamity in Philadelphia, in the Year 1793: and a Refutation of Some Censures (Philadelphia, 1794), 15.
 Pennsylvania enacted gradual emancipation in 1780.
 William Novak, The People’s Welfare: Law and Regulation in Nineteenth-Century America (Chapel Hill, 1996).
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Some archival materials related to this topic include:
Yellow fever vaccine boxes, College of Physicians of Philadelphia
Thoughts on the subject of a health-establishment for the city of Philadelphia, College of Physicians of Philadelphia
Benjamin Rush letter to Samuel Meredith, Philadelphia, Pa., 1801, Huntington Library
Select pamphlets respecting the yellow fever (1799), New York Academy of Medicine
Chagas Disease: Proceedings, Pan American Health Organization (1977), New York Academy of Medicine
Fever: an elegiac poem dedicated to the citizens of Philadelphia, by a citizen (1799), University of Toronto Libraries
John C. Bugher Papers, Rockefeller Archive Center
Baruch S. Blumberg Papers, American Philosophical Society Library
Related publications from our speakers:
Ship of Death: The Voyage that Changed the Atlantic World, by Billy G. Smith; Yale, 2013.
Mapping Ethnicity in Early National Philadelphia
A Melancholy Scene of Devastation: The Public Response to the 1793 Philadelphia Yellow Fever Epidemic, edited by J. Worth Estes and Billy G. Smith; Science History, 2013.
Integrating Evidence, Models and Maps to Enhance Chagas Disease Vector Surveillance
Bed Bugs (Cimex lectularius) as Vectors of Trypanosoma Cruzi
Urbanization, Land Tenure Security, and Vector-borne Chagas Disease
The Effects of City Streets on an Urban Disease Vector
See also recent work from our fellows:
Epidemic Preparedness in the Age of Chronic Illness: Public Health and Welfare Politics in the United States, 1965-2000, George Aumoithe
Unspeakable Loss, Distempered Awakenings: North America's Invisible Throat Distemper Epidemic of 1735-1765, Nicholas Bonneau
Michael Z. Levy is Associate Professor in the Department of Biostatistics, Epidemiology & Informatics and a Fellow at the Kleinman Center for Energy Policy at the University of Pennsylvania. He works at the interface of epidemiology, ecology and statistics to understand and control vector-borne and other infectious diseases. For the past 13 years he has focused his research on the control of urban Chagas disease transmission in Peru.