ACCORDING TO the singer and songwriter Leonard Cohen, “everybody knows” that a plague is coming. If they don’t know, then Laurie Garrett can quickly set them straight; the journalist penned The Coming Plague, the remarkable tome about the adventurer-scientists who have investigated infectious diseases over the past century. If there is not a plague on all our houses, there is at least a plague in every neighborhood. If you google “plague,” or even restrict yourself to a more scholarly search of references to “plague,” you will turn up not just the Black Death (which was probably caused by the bacterium Yersinia pestis) and the white plague, but also the plague monkeys, the forgotten plague, the slow plague, the Bombay plague, the ocean plague, duck plague, fowl plague, swine plague, mosquito plague, a plague of sheep, of cattle, of insects, of censorship, the plague year, plague days, plague dogs, and the Nevada mouse plague. Tracing its origins back to a Greek word for misfortune or blow, the word “plague” has been attached to just about anything that people fear or don’t like.
This widespread usage of the word “plague” in our society goes deep to a wound in our cultural psyche. None of these plagues, however, are actually the plague, the disease associated with the bacterium Yersinia pestis that in 1994 so terrorized the world that between 200,000 and 300,000 people fled Surat, India, before the rumors of their worst fears, and startled North American television viewers were faced with the sight of white-masked officials inspecting passengers arriving from India at our airports.
People’s fears of the plague are not without foundation. Beginning with the Justinian plague (AD 541–544) in Egypt, the plague crested around the world in at least three major pandemics and is at least partly responsible for pushing European history in new, unexpected directions. For instance, the second pandemic, the Black Death, killed off at least a third of medieval Europe—tens of millions of people—in just a few years in the mid-fourteenth century, even as it killed tens of millions of people in Asia and the Middle East. Economic and cultural changes, including peasants’ revolts, the rise of capitalism, and a loss of power by the church, all happened in its wake.
That story, and the horrors and wonders associated with it, has been recounted many times and should be essential reading for any thoughtful person in the twenty-first century. All the lessons about ecology, public health, personal hygiene, climate change, compassion, fate, and the dangers of globalization that anyone would wish to learn are there, plain for those who wish to see. This statement is also true for the story of the white plague, which is actually tuberculosis, another disease of animal origin discussed more fully elsewhere in this volume (and not to be confused with another white plague, which bleaches coral reefs).
The third plague pandemic started in China in 1855 and from there was disseminated around the world. Between 1898 and 1918, more than 12 million people in India died of plague. When the pandemic subsided, like a great flood it left small, stable pools of infection cycling among rodents, fleas, and the occasional unwary person in uneasy neighborliness on every continent except Australia. In the 1990s, about a dozen countries reported outbreaks of the plague. Most outbreaks occurred in African countries such as Madagascar, Mozambique, and Tanzania, but cases were also reported from Brazil, Ecuador, Peru, Mongolia, Vietnam, China, and the United States. In 1997, an outbreak of pharyngeal (infection at the back of the throat) plague, associated with eating raw camel meat, was reported from Jordan.
The plague is a disease of increasing concern because of the growth of urban slums globally and the unstable weather conditions associated with global warming and El Niño; these lead to changes in habitat for rodents in the countryside and explosions in rodent population in urban centers. We tend to view this disease as one that affects people, which, of course, it does. But we may learn something by taking a broader view. The plague is a disease of people, of fleas, of rodents, and, finally, of whole social-ecological systems.
In people, it comes in three forms: bubonic, pneumonic, and septicemic. To cause disease, the causative organism, Yersinia pestis, needs to get into the bloodstream, through an open wound, through transmission from one’s afflicted cat (say, by kissing the cat and inhaling the bug), or through a bite from an infected flea that then vomits the bacterium into the bloodstream. Much like the first European invaders feeding off the bounty of the American continents, once in the bloodstream the bacterium travels down the lymph rivers and bloodways, looking for appropriate places to settle and multiply. Peripheral lymph nodes—in the armpits or crotch—seem to be as good a place as any. These nodes swell painfully, and the infected person begins to feel some combination of fever, chills, headache, diarrhea, and constipation, moving on to generalized pain, rapid heartbeat, anxiety (understandably), staggering gait, slurred speech, and prostration. If untreated, 25 to 60 percent of people die. This bubonic form of plague cannot be transmitted from one person to another; an epidemic of bubonic plague depends on the continued presence of rodents and fleas. It is thus a true zoonosis.
In some people the infection moves to the lungs, where it causes pneumonia, which is a kind of adaptation of the organism to modern human society. Once in the lungs, it can be coughed out into the air and transmitted from person to person. Fleas and rats are no longer necessary. This form of the disease is called pneumonic plague. Now, or so conventional wisdom (recently called into question) has it, the bug can cause a serious epidemic or pandemic.
Although both bubonic and pneumonic plague can kill, they don’t kill everyone. At least some bodies are able to fight the disease off, and people recover. In some cases, both these forms of the disease lead to a full-blown septicemic (that is, blood-borne) form, in which people develop nervous and cerebral symptoms very quickly. Pretty well all of these people die.
But the plague is not just a disease of people. It is also a disease of fleas, which are themselves something of a wonder and worthy of a small aside here. In the history and mythology of the Judeo-Christian tradition, three and seven are two numbers used to express perfection. The third perfect number in Judeo-Christian stories is forty, which is the number of days Jesus spent in the desert, and which is an excellent age to have been, but which is not relevant to the life of fleas. The flea, aside from never experiencing the joy of reaching that pinnacle of the roller-coaster of life, the fortieth birthday, is a perfect parasite.
Besides being perfect, which in and of itself is annoying, fleas are exceedingly small. They have caused me to quarrel with my wife, whom I accused, no doubt falsely, of hallucinating tiny jumping, biting specks. They are brown, wingless animals with Twiggy-like bodies that can make them seem to disappear when they face you head-on, or more likely, rear-on, and that enable them to slip unpunished into cracks and cleavages. Suctorial mouthparts, eyes, antennae, and combs bedeck the chitinous head, giving them, under the microscope, the warrior-like appearance of a military beast from a planet in the Star Wars galaxy. The thorax is divided into three, which is another sign that the Creator, as one entomologist has said, had an inordinate love of insects. From each segment of the thorax extends a pair of powerful, claw-tipped limbs. If fleas, says a scribble in the margins of my parasitology notes from my student days, were the size of people, they could jump over tall buildings. More relevant to me is the fact that fleas the size of fleas can jump from the pillow on the couch to the base of my ear.
If one were to go to the flea for moral lessons, one could learn that if it drinks enough (blood) and copulates with sufficient frequency, even a small creature can have a significant impact on the world. For those who equate “good” with “natural” and “natural” with all those living things that aren’t us (a strange and pernicious equation), this may be a startling insight. Under the right conditions of decadence, a female flea, which lays from three eggs to some much larger number (probably a multiple of three) at a time, can put out a hundred of the glistening-white little things in a one-year lifetime. Fleas will lay more eggs when it is warm and the humidity is 70 percent or more. The adults live on warmblooded animals and eggs are laid on the animals, but many of them fall off into rugs and carpets, where, like jelly beans and chocolate eggs left unfound under the sofa cushion on Easter morning, they will hatch in two to twelve days (the median of which is seven).
The yellowish-white, bristling worms—teenagers of the insect world—feed on adult flea feces (full of dried blood) hiding out in the carpets and pet-resting places where they were dropped off. They are graced with anal struts, the flea version of tight jeans. Whereas people use their struts to unhinge each other’s psyches, the flea larval struts are hooks used to propel them in search of the ultimate hamburger (fecal blood casts from the adults) to stuff into their chewing mouthparts. They feed, grow, and molt three times, a process that can take anywhere from nine (three times three, under perfect conditions) to two hundred (or maybe two hundred and forty-three, which is a multiple of three) days. After the third molt, the larva spins a small cocoon, within which, like a most excellent pupil of the natural order, it pupates from seven days (under perfect conditions) to one year (usually two to four weeks, the median of which is three), after which the now-mature adult flea breaks out, seeking a host on which to feed.
In flea heaven, which has on occasion been situated on our couch, the entire life cycle takes three weeks. But fleas are quite willing to accommodate themselves to our imperfections and will stretch the process out, if they must, to two years.
There are about three thousand species and subspecies of fleas, of which only a few infest us and our pets. Pulex irritans, the human flea, moves freely between dogs and people, especially in the southern United States. This flea can transmit murine (mouse-related) typhus, which has less catastrophic effects than epidemic typhus, which is transmitted from rats to people by lice and has caused massive suffering and death worldwide. Epidemic typhus has been the subject of one of the classic biographies of a disease, Rats, Lice and History, by Hans Zinsser, which should be in every intelligent person’s library.
Ctenocephalides felis (the cat flea) and Ctenocephalides canis (the dog flea) infest dogs, cats, and people in a kind of natural free-trade zone, although the tapeworms that they sometimes smuggle across the borders only make a home in dogs. The cat flea is probably the most common flea infesting North Americans and is the most difficult to get rid of. Echidnophaga gallinacea, the sticktight flea of poultry, is God’s punishment for wayward dogs, cats, and young children (myself, many years ago, included) who decide to check out the inside of the chicken coop. In cats and dogs, this flea digs into the sparsely haired regions around the eyes, between the toes, and around the ears; in people, it just looks for uncovered, hairless areas.
Until relatively recently, there were few good remedies for getting rid of fleas, which spawned a huge industry in equally (in)effective treatments. Substances that effectively killed adult fleas (apart from the suffocating effects of baths) were toxic not only to fleas but also, because we share the animal kingdom with them, to us and to our pets. A California company proposed sealing off and heat-treating houses to get rid of insect infestations; this kind of drastic solution should be implemented just after first frost, in those parts of the country that get a first frost.
Other remedies for fleas proposed by several authors include: feeding the afflicted animal brewer’s yeast (a teaspoon daily for a cat, a tablespoon for a fifty-pound dog), and garlic (one or two cloves per day); regularly bathing the animal with non-toxic shampoos (to suffocate the fleas), followed by a good brushing; and rubbing the dog or cat with eucalyptus oil in water and/or brewer’s yeast, especially over the back around the base of the tail and in the neck area. Because treatments of afflicted animals kill only the few fleas unlucky enough to drown or get squished, baths and powders should be applied outside, where the fleas do not have the opportunity to escape into your carpet or couch. The standard veterinary literature reports that no controlled trials have demonstrated that these proposed treatments are effective. Even the herbal-treatment guru Juliette de Bairacli Levy somewhat despairingly admits that her protective lotion against ticks and lice, containing wormwood, beer, and vodka (a combination that would have a profound effect on many of us) does not affect the spartan flea.
In recent years, various hormonal remedies that interrupt larval development, combined with drugs that kill the adults, seem to be effective and safe. Removing fleas from your pet and discouraging them from reinfesting is only symptomatic treatment, however, and may aggravate the problem. Remember that many of the eggs and larvae are just hanging around the house, waiting for you to sit down. Cat fleas in particular are not fussy eaters, and, unless your whole family is on brewer’s yeast, garlic, and eucalyptus baths, sitting on the couch may become a bloodbath. If you are truly serious about fleas, you must remember that though you treat your dogs or cats with baths and powders, though you deck them in eucalyptus collars and feed them garlic, brewer’s yeast, or thiamine, yea, even though you spray them with the most powerful toxins, causing them to suffer even to the point of death, and treat not the couch and the rug, what you have done may not bring you to flea-free heaven.
Cat and dog fleas, so I am told, do not live well at altitudes higher than five thousand feet, so if you find that you cannot live with fleas, and you cannot, for reasons of conscience, live without them, you should lift your eyes to the hills. Know also, however, that even if you escape to Nepal or Tibet or Colorado, the tiny rat flea, Leptopsylla segnis, survivor in cold, dry climes, may await you there. There are fleas living on every continent, including Antarctica. Someone found a 200-million-year-old fossil flea in Australia.
There is no escape from the perfection of nature. It has predated us and shall outlive us. The religious among us might wonder if the creator invented the plague to make fleas sick and die and if we are the accidental hosts. If so, then getting rid of the plague may only encourage fleas.
Which brings us back to the plague.
Scientists suspect that Yersinia pestis, through one genetic mutation, adapted itself to transmission by flea bites thousands of years ago. Its cousin Yersinia pseudotuberculosis, which lives in rats and pigs and causes appendicitis-like food-borne illness in people, never made this adaptation. Fleas pick up Yersinia pestis from the blood of infected animals; the bacteria then multiply in the flea’s stomach until its upper gut (proventriculus) is blocked up. Really hungry and sick to the stomach, the flea heads out to a local blood bar, ready to feed on anything—your leg, a dog’s tail, a rat’s butt. After taking in a huge gulp of blood, the flea regurgitates some of the bacteria back into the glass (that is, the wound on your leg), then takes a crap into it and heads on home.
A lot of fleas probably feel miserable at getting this food-borne disease (the hamburger disease of the flea world), and some of them die. Even people who love all living things usually don’t care much about the personal sufferings of fleas, real or imagined, however, and no therapies have been developed to treat them and make them feel better. Penicillin would work, if one could devise a way to deliver the drug. As a veterinarian, I have had enough trouble trying to inject skinny cats and those small, nervous, snappy, skin-and-bone dogs without trying to imagine how one might inject a flea. Still, the nanotech people, I am sure, could find a way, should we decide to be more generous to other species than our reputation would suggest. One might also try anti-depressants, since they have worked in a wide range of other species; it wouldn’t cure them, but they would feel better while they died, which is, I suppose, the best most of us can hope for anyway.
If fleas are bearers of bad plague news, then our warm-blooded relatives the rodents are the poor suckers who have fed and housed them all these many years. Fleas had to wait a long time before getting a good meal of rat’s blood; rodents seem to have appeared on the planet some tens of millions of years ago, probably somewhere in Asia. Rats are even more recent. They appeared a few million years ago. Yersinia pestis causes in small rodents diseases similar to those in people, dogs, and cats. Wild rodents seem to be more resistant to the plague than domestic rodents, although plague has been known to cause major epidemics and die-offs in prairie dogs and other rural rodent cousins. Rats can carry a wide variety of diseases that can be transmitted to people, including plague, leptospirosis, typhus, spotted fever, tularemia, salmonellosis, and hantaviruses. I’ll come back to some of these a bit later.
According to Hans Zinsser in Rats, Lice and History, black rats (Rattus rattus) arrived in Europe from the Far East sometime between AD 400 and AD 100. They may have been fleeing the brown rats (Rattus norvegicus) that ruled Asia. They may have meant to warn the Europeans about their brown relatives. The Europeans didn’t listen. The so-called Norwegian rats (Rattus norvegicus, carried to Europe on Norwegian boats) followed from northern or northeastern China about a millennium after the black rats and pretty well wiped out their cousins.
Norway rats are Darwinian wonders, following and adapting to human habitats and adopting human behaviors with a vengeance. They reproduce with biblical perfection—about seven litters a year with seven pups per litter (well, with variance around those numbers)—and the females can breed eighteen hours after giving birth. This fecundity enables them to bounce back quickly from disease, pestilence, and human attacks. They are omnivorous and have been known to eat a third of their weight (another good biblical number) daily, voraciously consuming garbage, soap, candy, fruits, grains, seeds, and other animals, including each other. They live to be about three years old, so they live fast. They kill anything that gets in their way. They have studied us well, and bettered us.
Having been born in the Chinese Year of the Rat, I confess to having some empathy for the creatures, despite my Mennonite non-violence. My empathy does not extend so far, however, as the case described to me by a colleague who, having just returned from Tanzania, was called upon to perform some eighty dollars worth of medical and surgical procedures on an urban pet rat. Rats are intended to have honest, hard-working lives in neighborhoods other than my own.
No one knows how many rats there are in the world, although it would not be wildly outrageous to say that there are as many of them as there are of us. Although we are never, it seems, far from rodents, most residents of North America and Europe have had few encounters with them. Growing up in a clean prairie Canadian city, I never had much to do with rodents. Reports in 1998 of rats rampaging through Chinese cities, unhindered by feral cats and dogs, chewing through garments of hotel guests and damaging power lines, do not ring any bells from my own childhood. I imagine that if such events had happened, I would have suppressed the memory so deeply that only radical psychotherapy could retrieve it.
I once caught a mouse as it shambled along the street, close to the curb. It was Sunday morning, after church, and the sun was hot: a usual Winnipeg summer Sunday. The mouse, resisting my evangelical Mennonite attentions, bit my finger when I grabbed its tail. My parents, if I remember rightly, took me to a doctor. There was some concern about tetanus. Nobody mentioned diseases such as plague or hantavirus pulmonary syndrome (see chapter 11), although we now know the agents that cause them are present in western Canadian rodents. And once, when we came home from Sunday evening church services, I remember a lot of squealing and excitement in our family; there was a mouse in the mousetrap in the front hall. The concern in this case, I think, was about protecting our food supplies.
In the southwestern United States, ground squirrels can carry the plague, which has made for some exciting, if maudlin, made-for-television movies. In 2006, a woman in Los Angeles picked up bubonic plague from an unknown source, probably a flea that jumped from rodent to cat to person. The occasional cat has passed the disease directly to an affectionately stupid person by rubbing noses.
I suppose if I had grown up on a prairie farm, I might have learned about plagues of gophers. In this case, the gophers themselves were the plague, wreaking their damage on fields. Once, in high school, I went out to Eddy Wall’s farm, and we walked around with twenty-two-caliber rifles and looked for gophers to shoot. I don’t remember seeing any, though I shot a few tin cans off a fence post. At that time, no one knew that small prairie rodents around the world carry dozens of different kinds of bacteria, some of which (Bartonella species) have, on rare occasions, infected people and caused fevers or heart problems.
My first serious encounter with rodents was in Bihar, India. At nineteen years of age, I had hitchhiked overland from Europe to Nepal and India, where I worked as a young, idealistic volunteer. Actually, that is a romantic oversimplification; running out of money in Calcutta, stunned by the poverty there and my lack of money, I had talked my way into a temporary job with the Mennonite Central Committee, helping with grain storage and distribution in a grain-for-work program to build earthen dams and improve agricultural production.
My first day in Bihar, I slept on the floor of a bookshop, and some rats brushed against my cheek in the night. Several months later, I was part of a team effort to round up rats from a grain storage building; somebody made a lot of noise behind the stacks of grain sacks, and the rest of us waited for the rats to come out. We were supposed to kill them. One rat (the only one I remember, though I know there were a lot of them) came running out and skittered up the wide pant leg of one of the Indian workers, over the crotch, and down the other leg. At least, that was the story. Lots of excitement about possible theft of the family jewels, but no talk of plague.
I don’t remember our killing any rats at all; I wonder in retrospect whether our Indian co-workers, coming from a culture in which many of their compatriots feed and worship rats as companions of the god Ganesh, were just putting on a charade for the benefit of squeamish (and wealthy) westerners. They could have tried to explain things to us, but we, whose competitive and jealous God has no animal companions, would not have understood. Better to let us play our little games. Before I left Bihar, I acquired a pet chipmunk (another potential plague carrier), which I hauled around in my pocket and which ran up and down my arm to get snacks out of the palm of my hand. He later died after being accidentally locked in a refrigerator.
I tell you these stories not because I expect you to be interested in my experiences with rodents but because they indicate how far removed many of us in the industrialized world have become from the terrors of the Black Death. Yet the world would be a very different place if the plague had not turned Europe into a post-nuclear-like disaster area in the mid-fourteenth century. We are children of the plague not just in our language but also in many of our public institutions and political ideas: the collapse of feudalism, so I understand from historians, owed more to the deaths of farm laborers from the plague than it did to our enlightened moral progress as a species. And this collapse of feudalism in western Europe led to the rise of the middle class, capitalism, shopping malls, and Christian evangelical consumer cults.
Although most people think of the plague as a disease of people, and some of us (veterinarians) consider its effects on other animals, few of us think about the fact that the plague is also, perhaps most accurately, a disease of socio-ecological systems.
The Black Death occurred because the Mongol Empire had created a network for transport of goods, services, military technology, rats, fleas, and bacteria from central Asia to the gates of Europe. The Black Death occurred because Europeans, responding to longer summers and shorter winters between 700 and 1250, tripled their population, exhausted their agricultural lands, and were unprepared to adapt to the mini–ice age that followed. The Black Death occurred because prevailing winds changed, making Europe wetter—and central Asia drier—than it had been for a few hundred years. Mongol and Turk nomads, herding their flocks and joined by marmots, susliks, and other types of wild rodents, headed east and west in search of greener pastures. Europeans starved to death by the millions before the plague reached them, and those who survived the famines were weakened when the plague arrived. In this version of the narrative, Yersinia pestis may not even be important.
One author has suggested that the clinical signs and recurrent epidemics of the Black Death in Europe were more likely anthrax—another fatal disease people share with animals—than plague. Between outbreaks, anthrax can survive in spore form for decades and perhaps centuries in the soil (or in laboratories, but that’s a different story). What is important in this narrative is that the bacteria that killed individuals were opportunists taking advantage of climatic, environmental, socio-political, and economic changes. If the plague bacteria hadn’t done the job of killing, some other organisms would have; there are always plenty of candidates. And this is true for many human diseases: the specific agents (bacteria, viruses, prions) are less important than the hospitable contexts people create for them.
In 1993, a severe earthquake rattled parts of central India, damaging rodent habitats and resulting in an explosive emigration of rats from their own neighborhoods into nearby villages, where damaged grain storage facilities provided easy food and shelter. Wild rodents, under normal conditions of easy country life, may carry Yersinia pestis without getting sick. This phenomenon is not usually true of city rats or of rats living under crowded slum conditions. One could make a political lesson from this, but it seems too obvious.
About a year later, in August 1994, some people noticed a dieoff in the rat population; after thirty years of no reported cases in India, the plague had arrived. Within weeks, some eighty cases of bubonic plague in people were reported. Since bubonic plague isn’t transferred from person to person, health authorities treated the sick people and sprayed infested houses. Nobody died.
In late September, cases of pneumonic plague, which can be transmitted from person to person, showed up in Surat, a city of 1.4 million to the northwest of the original outbreak. When these cases were reported, more than 200,000 people headed out of town, and the plague became world news, with images of airport officials in Europe and North America wearing face masks and carefully screening airplanes from India. This was pandemic fear before SARS and avian influenza. But the pandemic never materialized. Some public health officials now wonder if the disease was plague at all.
Outbreaks of pneumonic plague among miners in the Democratic Republic of the Congo in 2005 and again in 2006 sickened thousands and killed hundreds, but they did not presage a pandemic explosion, as some had feared they would. Some scientists began to have second thoughts. Had Yersinia pestis changed its genetic colors? Were nutritional status and living conditions in the twentieth century, even at their worst, far better than living conditions a hundred years ago?
In Uganda, in 2004, a policeman from the West Nile region (ah, that cradle of Caucasians’ darkest fears) called a physician, who called staff from the Centers for Disease Control and Prevention in Atlanta who happened to be in the area for a field trial on treating the plague. They found that two people had come down with pneumonic plague, and despite many human contacts, only two others—their closest caregivers—picked it up from them. You had to be close enough to get sprayed by the coughing. So, people with pneumonic plague should stay off the stage at Stratford (a prime center of spraying others with well-articulated Shakespeare). But maybe our fears are larger than the threat. Fear of our own stories, our own perceived history, casts a long shadow across our cultures.
Several years ago, one of my colleagues, an anthropologist involved in international research, came to me with a problem. “Listen,” she said, “I’m working with some very dedicated scientists in a part of the world where plague has become endemic. Take a look at these reports, which concern one particular village. You’re the ecosystem health expert. What should these people do?”
From the unofficial research project reports she handed to me, and a review of two decades’ worth of peer-reviewed literature, I pieced together the following story:
About a century ago, the plague arrived in an area of what is now Tanzania along the trade routes and became established in several parts of the country, but not in one particular village and its environs. Then, several decades ago, the inhabitants of this village were plagued with an explosion of the rodent population, but without the occurrence of the plague. Nevertheless, the damage from the rats was sufficient to require the intervention of a special healer, who, in the manner of any good epidemiologist, intervened when the epidemic was at its peak and thus would decrease no matter what he did.
A couple of decades later, the rat plague returned, this time carrying human disease with it. Local people consulted the healer, who, it turns out, had not been paid the last time; after receiving appropriate apologies and offerings, he again suggested some cures. This time, however, perhaps because the people didn’t believe hard enough or do exactly the right things, the plague persisted. Over the decade of the 1980s, thousands of people became sick, and hundreds died.
In the meantime, veterinary scientists were trapping rats and taking blood and fleas from a random sample of people and dogs, looking for Yersinia pestis or antibodies to it. Every possible preventive action seemed to have been tried, but nothing worked, at least not very well. Some research suggested that dogs were carrying the disease; maybe if they got rid of the dogs? An anthropologist was sent in to talk to the people to see if he could determine why nothing seemed to work.
A complicated picture emerged from the anthropologist’s report, including what had been tried and why it hadn’t worked.
Doctors tried to quarantine sick people, but the patients resented this intrusion into their daily lives. Under quarantine, they were prevented from leaving their homes or villages to take part in agricultural activities, gather food, care for sick relatives, or attend special occasions; some people could find loopholes, however, especially through bribery. In any case, if rat fleas were carrying the disease, it was not clear that quarantine would have any effect besides making it look as if something were being done.
One could fall back on simply diagnosing and treating cases as they came up. Since the plague is generally treatable with inexpensive antibiotics such as tetracycline or streptomycin, this approach is often the most cost-effective for sporadic (non-epidemic) cases of the plague. Treating people quickly is dependent on local treatment centers that are accessible, well staffed, and stocked with antibiotics, however. In Tanzania, the local treatment centers were accessible but not always stocked with drugs; patient records were sometimes mixed up, lost, or leaked beyond the center, raising questions of confidentiality. Patients were to bring their own bedsheets and the like; some could not do so and were ashamed of their poverty.
In many parts of the world, diagnoses are made by playing the odds. “If you hear hoofbeats,” our professors at veterinary school in Saskatchewan used to say, “think horses, not zebras.” But that advice needs to be taken in context. In Kenya, you might well think “zebra” at the sound of hoofbeats. In North America, we often call a fever together with either respiratory or gut problems the flu; but often it’s not influenza (especially the gut form, since influenza in people is usually a respiratory disease). Sometimes that doesn’t matter; “flu-like” illnesses in North America are often caused by viruses, and doctors usually treat “flu-like” viral diseases similarly (chicken soup and bed rest). In parts of Africa where the plague is known to be endemic, a lot of non-plague diseases are called the plague, including malaria. Unfortunately, malaria is not treatable by antibiotics. If only some forms of the plague, broadly interpreted as any general illness, responded to antibiotic treatment, then what advantage did those modern methods have over traditional healing?
Public health authorities tried pesticide spraying and rat poisoning in houses. People from households that had been sprayed were asked to shut all windows and doors for six hours, as well as not to clean house for three to six days. Those householders did not like to share a dwelling with dead rats and fleas for that amount of time. Moreover, the pesticides had good market value and were either allocated according to favoritism or resold to farmers as treatments for crops and foodstuffs. Some people complained of becoming ill after spraying; chickens sometimes died, and cattle became ill.
Authorities proposed that villagers plaster and seal their houses so that the rats couldn’t get in from outside. Most of this work was supposed to done by women and by children under twelve, who were the ones getting sick and who did not have the energy for house renovations. Besides, there was a shortage of water needed for plastering, and men controlled the money that would pay for plastering. It was not done.
Households could move food storage outside so that the rats wouldn’t come into the house: traditionally, the maize was stored outside the house. However, a decline in maize production associated with an increase in cash crop production related to an opening of world markets made maize more valuable as a tradable commodity; this development, together with a decrease in social trust (related in part to competitiveness and modernization), increased the need for vigilance. Hence the maize was now stored in the wooden ceiling of the house. Rats followed the maize into the house; this move made the dogs happy to stay around the house as well.
Public health officials recommended that householders clear shrubs and bushes from around the houses and field crops so that rats would have fewer places to hide. But arable land was scarce, and people wanted to maximize land use by planting very close to the house. Borders of fields were planted with trees to prevent soil erosion, with grasses as cattle feed, and with medicinal plants for household use. These practices were encouraged by some government agencies (obviously not those involved in eradicating the plague) to conserve soil and water. Some shrubbery was also maintained as a link to family ancestors, who were believed to live in the shrubs near the house.
Even something as apparently simple as removing food scraps from near dwellings was a problem, since this organic “waste” was thrown into the fields around the house to serve as fertilizer for the crops.
Since women and young girls prepared the food, they were getting the plague. Since children played with dogs that were infected by fleas from rats, they also got the plague.
What should these people do? To keep up agricultural production and prevent soil erosion, farmers should plant bushes and shrubs around their houses and fields. To prevent the plague, they should pull them up. To make more money, they should plant more cash crops. To bring down the price of local food, they should plant more maize. To improve their health, they should cooperate with their neighbors and move their grain into outside storehouses. To become more competitively efficient in the global market, they should compete with their neighbors. How could they decide the right path? Was there a scientific answer?
When I recounted this scenario to Jerry Ravetz, a philosopher of science and a colleague, he suggested (not without some satisfaction, I think, since philosophers, like mathematicians and theologians, seem to thrive on insoluble problems) that there might be no solution to the plague problem in Tanzania. We were up against irreducible complexity.
One might also, on a world scale, say we were up against some major cognitive dissonance. When I became a veterinarian, I was introduced to the idea that rats are intelligent, friendly, social animals that make ideal pets, especially for children. They can do tricks. Hence the eighty-dollar vet bill for the rat I mentioned earlier. Personally, I get a headache trying to reconcile rat worship, rat companionship, and the ravages of the plague. One might suggest that we have need of a kind of eco-narrative therapy for our dysfunctional species, but where would we begin?
Clearly the plague, once the terror of Europe, is no longer the killer that it once was. What did Europeans do correctly that the Tanzanian villagers can learn from?
For one thing, it has become clear that no single perspective (environmental, public health, economic, male, female) or scale (animal, household, region, world) will give us the whole picture or, if there is one, the whole solution. If the plague is seen to be a disease of individuals caused by Yersinia pestis, then the treatment is an antibiotic, and the delivery of disease care is where time and effort should be focused; better diagnostic laboratories need to give people greater confidence that they are being treated by the right drug for the right disease. If the plague is viewed as a disease of household dogs, rats, and fleas, then efforts should target controlling dogs, spraying for fleas, killing rats, and making sure that people have better housing. Land use planners and ecologists can monitor ecological change and target interventions when they are likely to have the greatest effects. These measures, too, are important.
Yet none of them worked in this village, because the plague is also a disease of socio-ecological systems. The price of maize, the national debt, relations between men and women in the household, the sense of neighborliness between households all need to be considered. Addressing these issues requires not just medical and technical expertise but also a deep cultural engagement and a democratic debate about trade-offs: what kind of a society do we want to live in?
Similarly, outbreaks of the plague in Mexico, Peru, Madagascar, and other countries in the 1990s could be attributed to a mix of bacterial nests left over in various landscapes from the pandemic a hundred years earlier, as well as to a lack of public health infrastructure (reflecting government spending priorities, which often reflect the muddle-headed priorities in the World Bank and the International Monetary Fund) and to cyclic meteorological events (El Niño), which have been intensified by global warming, which is the result of fossil fuel use, which is associated with industrialization in Europe and North America.
In the 1990s, the ecologist C.S. “Buzz” Holling brought together an international alliance of scholars to try to understand such complex social-ecological systems. They call themselves the Resilience Alliance and have contributed a great deal to our ability to develop appropriate response and management strategies that will promote both ecological resilience and human well-being. There are other, similar networks, including the International Society for Ecology and Health (EcoHealth for short), the Network for Ecosystem Sustainability and Health (NESH), and the whimsically named Dirk Gently Gang.
These networks are working toward developing a new kind of science capable of asking, and perhaps answering, questions too big to be contained in the laboratory: How can a convivial human existence on the earth be created and prolonged? When that existence ends, what grand, multilayered novel do we wish to tell of our time here on the earth? Will it be a tragedy? A comedy (in the Shakespearean sense of having a happy ending)? Or merely a tawdry television melodrama?
Although I am not an alarmist with apocalyptic visions of the Black Death wiping out modern civilization, I do know that the stories that move national policies today—tales of competitiveness and economic efficiency, economies of scale and unfettered trade—are also tales of sloppy biological thinking. Current national and international policies in the 1990s will most assuredly open the doors for more interesting, more devastating, and more widespread epidemics of disease. The word “plague,” according to our best prognostications, shall remain an essential ingredient for intelligent discourse for many centuries to come.
The stories we choose, and the responses to disease, are not scientific choices. They are moral animals, with scientific organs and possibly tragic consequences. If we continue to act fast and loose with our technology and drugs, we may be left without a technology to save us and with the words of Albert Camus ringing in our ears:
None the less, he knew that the tale he had to tell could not be one of final victory. It could only be the record of what had had to be done, and what assuredly would have to be done again in the never ending fight against terror and its relentless onslaughts, despite their personal afflictions, by all who, while unable to be saints but refusing to bow down to pestilences, strive their utmost to be healers.
ALBERT CAMUS, The Plague