The Plague Cycle

by Charles Kenny

  Syphilis’s clear association with sex made it a convenient weapon of those trying to outlaw prostitution. Many fifteenth-century towns had, alongside sanctioned town brothels, municipal baths that were home to prostitutes—in London, they were concentrated in Southwark, on lands owned by the bishop of Winchester. But as knowledge of the new disease spread, the attraction of casual sex reduced. The scholar Erasmus, noting the decline of steam baths in Brabant in 1526, reported that “twenty five years ago, nothing was more fashionable.… Today there are none, the plague [syphilis] has taught us to avoid them.”33

  A moralizing attitude toward syphilis continued despite widespread understanding that condoms could protect against the disease. The Ancient Egyptians used linen sheaths to prevent sexually transmitted disease, and the Romans followed the Greeks in the use of animal bladders.34 Gabriele Fallopio, an Italian anatomist who lived in the first half of the sixteenth century and gave his name to fallopian tubes, described his invention of a made-to-measure sheath of linen soaked in salt water tied with a ribbon at its base. He also claims that he gave eleven hundred men sheaths to use during sex and not a single one caught syphilis when using one of them.35 Mrs. Perkins, purveyor of “implements of safety,” who advertised her condoms for “ambassadors, foreigners, gentlemen and captains of ships,” did more for public health and, in particular, women’s health in eighteenth-century Britain than people like Malthus who suggested abstinence was the only acceptable way to avoid either pregnancy or disease—but Malthus was long on the winning side.

  Alarmed by the proportion of army recruits rejected on the grounds that they were syphilitic, Britain introduced the Contagious Disease Acts in the middle of the nineteenth century, which forced prostitutes in garrison towns to register. Those identified as “common prostitutes” by the police were subject to physical inspection using the (incredibly unsanitary and invasive) steel penis of the speculum. Women declared diseased were locked up in quarantine hospitals. (Men, it should be noted, weren’t subject to inspection or punishment.) As late as the First World War, the British rejected issuing condoms to troops, on the grounds that soldiers were better sick than enticed into mortal sin (again, nothing was said about the effect on women).36

  * * *

  A greater understanding of the biology of infection increased pressures for the use of exclusion to preserve public health. The germ theory of disease became scientifically dominant thanks in large part to the work of the Frenchman Louis Pasteur and the German Robert Koch in the second half of the nineteenth century.

  In 1876, Koch extracted anthrax bacteria cells from a diseased animal, grew the bacteria in his lab, and then transmitted them to healthy animals to give them the disease. Over the next eight years he followed that up with discovering the organisms responsible for tuberculosis (previously thought to be inherited) and cholera (a favorite of those who thought stench caused disease). Koch used his newfound status to call for extended quarantines and isolation. Many of Koch’s initial dissenters were motivated to oppose the germ theory in part by fear of what it implied for public policy. Take Florence Nightingale, nurse-hero of the Crimean War:

  “The disease-germ fetish, and the witchcraft-fetish, are the produce of the same mental condition.… The germ hypothesis, if logically followed out, must stop all human intercourse whatever, on pain or risk of disease or death.”37

  Nightingale’s fears were prophetic. Isolation remains a powerful tool to reduce the spread of disease, but when it is applied as a permanent measure to “high risk groups” rather than sick individuals, exclusion can be the cause of considerable harm.

  By 1889, homeowners and medical attendants in the UK had the duty to report a range of diseases—from smallpox and diphtheria through measles and whooping cough. Medical officers could then decide whether those affected should be isolated at home or in a hospital and whether to disinfect homes, clothing, and bed linen.38 At the turn of the century, tuberculosis victims in Britain and elsewhere were frequently locked up in sanatoriums, segregated by sex, and subject to strict discipline.39 The British public “was becoming acclimatized to a new medical rationality which might involve the trimming of its liberties,” suggests historian of medicine Dorothy Porter.40

  Exclusion was a particularly big problem when germs were used as an excuse to keep out and maltreat whole ethnic groups with no more scientific basis than the theory that Jews poisoned wells to start the Black Death. The US Immigration Act of 1891, which provided a foundation for federal oversight of migration, banned criminals, polygamists, prostitutes, contract laborers, and those with a “loathsome or contagious disease.” Poor immigrants and those from outside of Europe faced harsher medical scrutiny—thick necks were taken as a sign of goiter, shortness of breath as a result of lung diseases, rashes as evidence of ringworm. In 1898, only 2 percent of all those denied entry into the US were excluded on medical grounds, but by 1915, the percentage had climbed above two-thirds.

  Similarly, US officials on the Mexican border oversaw a process whereby migrants were stripped, showered with kerosene, examined for lice, and vaccinated against smallpox. Some of the first undocumented immigrants into the US were those who, in the 1910s, crossed unwatched sections of the Rio Grande rather than submit to invasive medical examination and disinfection.41

  The third recorded plague pandemic also involved a racist response to infectious threat. It emerged in Yunnan, China, in the 1850s and spread via Canton to Hong Kong, where, in 1894, Alexandre Yersin identified the bacteria that caused it (it was named Yersinia pestis in his honor). From there, the steamers of the British Empire took the lead in transporting it worldwide.

  Plague arrived in San Francisco in 1900. Echoing a conflict that had raged since the very first quarantine in Dubrovnik and continues today, business interests lined up against government officials in charge of health over the question of imposing movement restrictions.42 But it’s hardly as if those calling for quarantine were acting under the most rational (or noble) assumptions, as was demonstrated when the quarantine was finally imposed. It was applied solely to Chinatown and anyone of Chinese descent trying to leave California.

  On May 19, 1900, San Francisco medical staff swarmed over Chinatown restraining anyone who looked Chinese and attempting to inoculate them with an experimental plague vaccine. Chinese merchant Wong Wai brought a suit against the San Francisco Board of Health, claiming that compulsory inoculation was “a purely arbitrary, unreasonable, unwarranted, wrongful and oppressive interference” with his liberty. The judge, William Morrow, agreed on the basis that the compulsory order had been “boldly directed against the Asiatic or Mongolian race as a class, without regard to the previous condition, habits, exposure or disease, or residence of the individual.” As such, it clearly violated the right to equal protection under the law guaranteed by the US Constitution.43

  The ingrained response to keep distance from a person suspected of being sick continues to this day. During the AIDS epidemic, Delta airlines tried to ban HIV-positive people from flights, and Tulsa authorities drained a swimming pool after a gay group used it. (Meanwhile, US senator Jesse Helms called for a reduction in spending on AIDS care because “deliberate, disgusting and revolting conduct” had caused infection in the first place.)44 From 1990 to 1993, HIV-positive Haitian immigrants were held at Guantánamo Bay, one of many instances to come of America’s using the island to ignore human rights standards that would be required on its own soil.45 And it wasn’t just the US—many countries worldwide imposed some sort of restriction on the entry or stay of foreigners with HIV.

  Or consider Ebola: the disease is featured in a number of movies because it kills so horribly, leaving victims a bleeding sack of infection. In 2014, West Africa suffered history’s worst Ebola epidemic. The outbreak killed thousands before Ebola disappeared back to its animal reservoir, thanks in part to curfews, isolation of sick people, and safe burial of disease victims. But complicating the response, local people in infected areas became mar
kedly unfriendly to medical staff trying to help them. Doctors and nurses arriving to collect victims were threatened with machetes and stones, and their cars were surrounded by angry mobs telling them to leave. In July, staff from Doctors Without Borders, a Western NGO, told the New York Times that it “is very unusual that we are not trusted” and complained that people were turning for help to local witch doctors instead of foreign NGOs.46

  On September 16, 2014, an official delegation reached the village of Womey in southeast Guinea to spread news about the Ebola threat. They also sprayed bleach and water on cars and common areas as a preventative measure. As the aroma of oxidant spread through the compound, the rumor started that the officials were spraying the Ebola virus itself. Village women began to chant “What do you do when someone comes to kill you?” The men replied: “We will kill them.” The delegation’s security guard fired a warning shot and chaos ensued. Two days later, police found eight bodies of delegation members in a latrine ditch, many with their throats slit.47

  Meanwhile, halfway around the world, Georgia representative Phil Gingrey wrote to the US Centers for Disease Control and Prevention noting “reports of illegal immigrants carrying deadly diseases such as swine flu, dengue fever, Ebola virus, and tuberculosis are particularly concerning.”48 The reports might have been more concerning had they turned out to be true, but they show that people all over the planet still respond with broad exclusionary instincts to infectious disease risk.

  In the past few years, the risk of leprosy, tuberculosis, and even bedbugs has been used by US television and radio pundits as justification for turning back travelers and immigrants.49 Sadly, Covid-19 provoked similar responses, with reports of increased abuse of Asian-Americans in the United States and Europe, and of worsening discrimination against Africans in China. Particularly monstrous was the stabbing by a Texan of a two-year-old and a six-year-old because he thought they were Chinese and spreading the disease. Xenophobia clings to many official responses as well, including recent travel bans.

  * * *

  Our instinctual response toward disease threats may even have shaped the nature of whole societies. The “parasite stress” theory of attitudes and behavior suggests that the more infectious diseases are present in an area, the more people are afraid of strangers, keep to their own communities, and show violence toward others. Across countries, those with historically higher infectious disease prevalence have populations that are less individualistic, more willing to respect authority, and less likely to want people of a different race as neighbors. They’re also more conformist and willing to restrict rights and liberties, according to Mark Schaller and Damien Murray of the University of British Columbia.50

  Though there is an intuitive appeal to a relationship theory in which disease breeds distrust which breeds conservatism, the evidence mustered to date by parasite stress theorists is more circumstantial than beyond reasonable doubt.51 It would be a considerable mistake to fall into a state of “pathogen determinism.”52 Schaller and Murray themselves are careful to point out that culture can change rapidly. But pathogen stress—an ingrained behavioral response to a high disease burden—may still be one factor in shaping societies, potentially with long-term consequences. More positively, the theory also suggests that a world of declining disease threats should be one of greater peace, liberty, and cohesion, with lower pressures toward exclusion. That would be good news, because, though historical and modern evidence suggests that isolation and social distancing can be effective in slowing the spread of infection, these measures frequently fail in the long run—and even where they do work, they often carry a high cost by trapping the healthy along with the sick and disrupting trade and travel.

  However necessary, Covid-19 exclusion has tragically illustrated the measure’s immense cost as a response to disease in the modern world; it has spurred the most rapid contraction of the global economy in a century. We’ll see that it has also demonstrated the counterproductive futility of most travel bans on a globally connected planet.

  Our deepest habitual reaction to disease is one of the most problematic in the aftermath of civilization and globalization. It took sanitation and a medical revolution to push back infection in an age of urbanization and connected disease pools. And it will take public health and further medical advances to overcome Covid-19 and the threats that come after.

  CHAPTER SIX Cleaning Up

  All smell is, if it be intense, immediate and acute disease.

  —Edwin Chadwick

  One of Bazalgette’s sewers, still operating in London (Credit: “The Other Aye” by sub-urban.com is licensed under CC BY-ND 4.0)

  Like exclusion, keeping clean is a prehuman response to disease threats. Rats spend as much as one-third of their time awake attending to their toilette routines of chewing and licking fur and skin. Primates—apes, not least—spend many hours combing the hair of their fellow pack-mates and picking or even biting off ticks and other bugs. (The high-status apes get the most attention. It isn’t just among humans that the upper classes get the best healthcare.)

  Cooking is a sanitary response developed by early humans—it kills microbes before we eat them. And, in part, cooking habits might vary around the world thanks to the risk of infection. Paul Sherman at Cornell University and his student Jennifer Billing looked at forty-five hundred recipes for preparing meat from cookbooks across thirty-six countries and found that the hotter the country, the spicier the average recipe. Danish and Norwegian food tends to be bland, Mexican and Indonesian dishes can be blistering. Within China, the (climatically hotter) south prepares hotter dishes than the (climatically cooler) north.1 Indian dishes use an average of nine spices to England’s two.

  Sherman and Billing suggest one reason for the link between the heat of the air and the heat of the food: many spices kill bacteria. Garlic, onion, allspice, and oregano inhibit or destroy every bacterium they’ve been tested on. Spices have to be grown and prepared; that effort is more worthwhile in places where infection from spoiled meat is more likely—hot climates that tend to be “pathogen rich.”2

  But civilization posed an obvious challenge beyond what to load on the spice rack: namely, tens of thousands of people living and excreting in close proximity. More than five thousand years ago, the city of Mohenjo Daro in modern-day Pakistan developed a solution: it boasted many houses with bathing rooms alongside toilets that emptied into covered sewers large enough for a person to walk down.3 This may have been the global high point for sanitation up until the late eighteenth century, although some ancient Chinese cities constructed similar wonders of hydraulic engineering.

  Around 200 BCE, Chang’an, the capital of the Han Empire, relied on an urban water system that included supply, storage, rainwater management, and drainage. Marco Polo’s description of Chang’an from a millennium later suggests the city had a huge river on one side and a lake on the other. The “river, which enters by many channels, diffuses throughout the city, carries away all its filth and then flows into the lake, from which it flows out toward the ocean. This makes the air very wholesome.” Polo observed that “these people are used to taking cold baths all the time.… It is their custom to wash every day, and they will not sit down to a meal without first washing.” There were three thousand public baths in the city to clean them.4

  Chinese cities were conscientious about removing excrement, carting out “night soil” for fertilizer use. And because of internal peace, towns spread beyond their walls, reducing the problem of overcrowding. There were fewer animals crowded into cities as well: the Chinese diet contained little meat. That meant a lower risk of infections shared with livestock.

  Polo also noted that the khan regularly entertained forty thousand at a banquet and that the guests apparently enjoyed a high level of sanitary protection. The waiters, some of the khan’s barons, “have their mouths and noses swathed in fine napkins of silk and gold, so that the food and drink are not contaminated by their breath or effluence,”5 a practice that
came back into fashion in 2020.

  In Europe, imperial Rome enjoyed some of the same sanitary benefits. Aqueducts delivered more than forty gallons of clean water per person per day to the city in the third century CE—feeding private houses, massive public baths, and more than one thousand fountains. Sewage was less advanced, but the Cloaca Maxima, running from the center of the city to the Tiber River, was linked to smaller tributary sewers throughout Rome. Cesspits were emptied at regular intervals, their contents to be used as manure on the fields. And there were specific government offices responsible for maintaining drains, paving and cleaning streets, preventing foul smells, and overseeing baths, brothels, taverns, and water supplies.6 This—along with the tribute and migrants of empire—is what allowed the city to grow so large.

  But as was said earlier, life expectancy in the city remained low—certainly, below thirty years. One reason was high population density. Most Romans were housed in flimsily constructed apartment buildings, supposedly restricted to a seventy-foot height by Emperor Augustus. That would have made the city, one million strong at its largest, a breeding ground for airborne diseases as well as numerous pests, including lice, fleas, rats, and mosquitoes.