Disease

_Disease

Cities were microbe heavens, or, as British microbiologist John Cairns put it, 'graveyards of mankind.' The most devastating scourges of the past attained horrific proportions only when the microbes reached urban centers, where population density instantaneously magnified any minor contagion that might have originated in the provinces. Any microbes successfully exploited the new urban ecologies to create altogether novel disease threats.

Laurie Garrett, The Coming Plague

A thorough understanding of the AIDS pandemic demands a commitment to the concerns of history and political economy: HIV has run along the fault lines of economic structures long in the making.

Paul Farmer, AIDS and Accusation

In the halcyon days after World War II, when the advance of science and economic prosperity inspired government leaders and leading academics to predict a coming era of worldwide peace and prosperity, medical professionals were predicting the end of infectious disease. Universal health was set as a realistic and achievable goal. The U.S. Surgeon General in 1967 said it was time to close the door on infectious disease. There was some reason for this optimism. As a result of a worldwide vaccination campaign, smallpox had been completely eliminated, the last case in the world being diagnosed in 1979. Malaria, one of the world's major killers, had been reduced worldwide and even eliminated in some areas by controlling the vectorthe mosquitothat spread the disease and through the development and massive distribution of curative drugs. Tuberculosis, the major killer of the nineteenth century, was disappearing. The U.S. Surgeon General declared that measles would be eliminated by 1982 with an aggressive immunization campaign. Jonas Salk developed a vaccine for poliomyelitis, the scourge of childhood, and the development of antibiotics promised to rid us of every infirmary from pneumonia to bad breath. Then, in the space of a decade, everything changed.

AIDS was one of the shocks that changed universal optimism to what Marc Lappe (1994) called 'therapeutic nihilism,' an attitude common today among hospital personnel that nothing will work to cure patients. But there were other reasons for the change: the

emergence of antibiotic-resistant strains of disease; the reemergence of malaria, cholera, and tuberculosis in even deadlier forms; the emergence of other new diseases, particularly Lyme disease, dengue-2, and hemorrhagic fevers such as ebola that result in massive internal bleeding and have mortality rates of up to 90 percent. Measles, supposed to be eradicated from the United States in 1982, was ten times more prevalent in 1993 than 1983. These developments and others have required medical researchers in biology, epidemiology, and anthropology, among others, to reexamine the relationship between human beings and the microbial world, particularly those pathogens that cause disease. It is clear that we underestimated the ingenuity of microbes to adapt to our adaptations to them and failed to appreciate how our patterns of social, political, and economic relations affect the emergence and transmission of disease.

Each age, it seems, has its signature disease. Bubonic plague in the fourteenth and fifteenth centuries emerged as a result of the opening of trade routes to Asia, carried by merchants and warriors from the middle of the then world system west to Europe and east to China. Syphilis spread in the sixteenth and seventeenth centuries through increased sexual contact of people in towns and cities. Tuberculosis was the disease of the nineteenth century, spread through the air in the densely packed cities and slums of Europe, the United States, and the periphery.

As we shall see, AIDS is very much the signature disease of the latter quarter of the twentieth and the beginning of the twenty-first century, serving as a marker for the increasing disparities in wealth between core and periphery and the accompanying disparity in susceptibility to disease. More than 98 percent of deaths from communicable disease (16.3 million a year) occur in the periphery. Worldwide 32 percent of all deaths are caused by infectious disease, but in the periphery infectious disease is responsible for 42 percent of all deaths, compared to 1.2 percent in industrial countries (Platt 1996:11).

Table 8.1 summarizes the major diseases afflicting the world today, the number of people affected, annual mortality, and whether the disease is on the rise, declining, or stable.

The fact that each historical epoch has its characteristic illness reveals clearly that how we livethe social and cultural patterns at any point in time and spacelargely define the kinds and frequencies of diseases to which human beings are susceptible. The questions we need to ask are; what do we do that exposes us to disease? What do we do that exposes others to disease? How do we create the conditions for unique interactions between pathogens, their environments, and their hosts? Furthermore, what features of human societies make pathogens more or less lethal?

Many of the things we discussed in previous chapters are relevant. For example, increases in population density clearly relate to the emergence and frequency of disease, as does the division of the world into rich and poor. The crowding into cities of rural workers and peasants as agricultural land becomes concentrated in the hands of a few influences disease susceptibility. Public policy that makes economic growth a priority and neglects health programs encourages the spread of disease, as do International Monetary Fund structural adjustment programs in peripheral countries that demand the cutting of health, sanitation, and education programs. The alteration of the environment has enormous consequences for the spread and emergence of disease.

As food is available to those who can pay for it, so too, medical cures are available largely to those with the money to buy them. In a capitalist medical system, as in a capi-

TABLE 8.1 Characteristics of Major Infectious Diseases, 1999 Estimates by Death Counts*

*Data collected from WHO member organizations.

Source: World Health Organization, https://filestore.who.int/~who/whr/2000/en/excel/annextable03.xls.

talist food system, market demand, not need, determines what and how much is produced. Of the 1,233 new medicines patented between 1975 and 1997, only 131 percentwere for tropical diseases. One American drug company stumbled on a drug for sleeping sickness, currently infecting some 300,000 people a year, largely in sub-Saharan Africa. The

drug company that now owns the patent for the drug, however, has decided not to market it because of the poor profit potential. It did donate the patent to the World Health Organization (WHO), but WHO lacks the financial resources to develop it (see Tardieu 1999). Malaria infects an estimated 500,000 and kills from one to three million people a year, mostly in poor countries, yet drug companies invest little to find cures because there is little profit in addressing the needs of the poor. 'The poor have no consumer power, so the market has failed them,' said Dr. James Orbinski, international president of Doctors Without Borders/ Medecins Sans Frontieres; 'I'm tired of the logic that says, 'He who can't pay, dies'' (McNeil 2000). Thus while drug companies invest some $27 billion a year in research, most of that is for drugs to grow hair, relieve impotence, fight cholesterol, control depression and anxiety, and relieve arthritis and high blood pressure, all problems of the wealthiest 10 or 20 percent of the world's population. Those priorities make good economic sense in the short-term but, given the rapidity of the spread of disease, endanger everyone.

Infectious disease, of course, is not the only health problem we face. Environmental pollutants, often a direct outgrowth of industrialization, cause sickness. For example, asthma, often aggravated by industrial pollutants, is on the rise. Millions of people face malnutrition and starvation, conditions that further expose them to disease. Commercially promoted products such as alcoholic beverages and tobacco endanger health. Of the estimated 1.1 billion smokers in the world today, 800 million are in the periphery (World Health Organization, The Tobacco Epidemic, 1995). The WHO estimates that four million people die annually from tobacco; this figure, they say, will increase to 10 million by 2030, and 70 percent of these deaths will be in developing countries. As cigarette sales continue to fall in the core in response to antismoking campaigns and state legislation, cigarette companies, with the support of core governments, have intensified their efforts to sell their products to people in other countries, particularly to women and the young. For example, the United States has used free trade arguments to pressure other nations Thailand, Taiwan, and South Koreawith economic sanctions to open their markets to American cigarettes. In such cases it is easy to see a direct connection between the capitalist world system and the onset of disease. However, the relation that exists between the culture of capitalism and infectious pathogens is often more subtle and hidden.

A Primer on How to Die of an Infectious Disease

Human beings swim in a sea of microbes; we eat them, breathe them, absorb them through skin openings and membranes. Most do us no harm, and many are useful. Millions of bacteria live in our intestinal system to aid digestion and in nature serve as catalysts for decomposition of material that can then be reused by plants and animals. Many we never meet, as they exist in distant parts of the world. Some microbes, however, do harm us. Harmful or pathogenic microbes include bacteria, viruses, and parasites that invade our bodies and cause illness and, in some cases, death. The question we need to ask is what determines the relationships that we have with the infectious pathogens whose world we share?

To answer this question let's ask what it requires for a pathogen to kill us; that is, what does it take for us to die of an infectious disease? At least four things have to hap-

AIDS has become the signature disease of the culture of capitalism, striking particularly hard in the poor countries of the periphery, such as Gambia where this sign advises condom use.

pen. First, we must come into contact with the pathogen or a vectorsuch as a mosquito, tick, flea, or snailthat carries it. Second, the pathogen must be virulent, that is, have the capacity to kill us. Third, if we come into contact with a deadly pathogen, it must evade our body's immune system. Finally, the pathogen must be able to circumvent whatever measures our society has developed to prevent it from doing harm. As we shall see, human actions are critical in each step.

First, what actions of human beings increase their likelihood of coming into contact with an infectious pathogen ? Various behaviors may serve to expose an organism to an infectious agent. For example, carnivorous animals create an opportunity for pathogens to spread when they eat the flesh of other animals; animals that congregate create opportunities for the spread of pathogens by physical contact. Since human behavior is dictated largely by our culture, cultural patterns that characterize human populations play a major role in creating or inhibiting opportunities for pathogens to spread. Actions that change the environment or change the size, density, and distribution of human settlement patterns increase or decrease the likelihood of our meeting an infectious parasite or influence the size of the parasite population. The emergence of Lyme disease is a good example of many of these factors.

Lyme disease was first reported in 1975, when two women, in Old Lyme and Had-dam, Connecticut, reported to a Yale physician that their children had strange symptoms,

including aching bones, malaise, and neurological symptoms such as poor memory and concentration. Study revealed that the disease, now spread throughout much of the United States, is carried by four varieties of ticks. The question is, why did it quite suddenly become a major health problem? The reason apparently has to do with human alterations of the environment along with human settlement and recreational patterns.

In the seventeenth and eighteenth centuries much of the New England forest was cleared for farming. As farming declined the forests grew back, but with a very different ecology than the one that existed originally: Gone were certain species of animals, such as wolves, bears, and mountain lions, and populations of deer and mice, once controlled by these predators, increased dramatically. Also increasing were the populations of ticks associated with deer and mice and, with the ticks, the Borrelia organism, a pathogen they carried in their salivary gland. As human beings built settlements (suburbs) along the forests and ventured into them for recreational activities, they were exposed to the tick. The result was Lyme disease.

As noted above, coming into contact with a pathogen is not, in itself, sufficient to kill us. The pathogen itself must be virulent enough to disrupt critical bodily functions or reproduce so extensively in the body that the damages it causes will result in death. There is obviously a big difference between 'catching' a cold, and 'catching' HIV. We seem to take for granted that some diseases are more severe than others, but the reality is far more complex. A pathogen that is harmless to one host may be lethal in another. There is a herpes virus, for example, that has evolved to survive, spread, and do no harm in one type of monkey but is 100 percent lethal when it infects another type (Garrett 1994:573).

Generally, it is not in the best interest of a parasite, bacteria, or virus seriously to harm its host; it is far better to allow the host to survive, to provide an environment for the pathogen to reproduce and spread. Furthermore, it is a distinct advantage to the pathogen if the host remains mobile to help the pathogen spread to new hosts. The rhinoviruses that cause the common cold, for example, reproduce in the cells that line the nasal passages; they are shed by sneezing or by a runny nose. If a person with a cold wipes the nose with a finger and then touches the finger of another person, the exposed person may inhale the contaminated air or touch the finger to his or her mouth. However the pathogen is spread, it requires the host to move, so killing or disabling the host is counterproductive.

Thus most microbes that we come into contact with and even those that infect us do us little or no harm. However, there are certain exceptions to the rule that microbes should not harm their host. First, the newer the disease, the more deadly it is likely to be, since microbe and host will not have had sufficient time to adapt to each other. Anything that human beings do that exposes them to diseases to which they haven't been previously exposed increases the likelihood that the disease can kill them. The destruction of the peoples of North, South, and Central America in the sixteenth and seventeenth centuries, as we saw in Chapter 3, is a case in point. Having never been exposed to such diseases as smallpox, measles, influenza, and even, in some cases, a common cold, millions died. Something as simple as increased travel can bring people into contact with a disease that is far more lethal for them than for the people who share their environment with the pathogen. Intestinal illnesses that are the bane of travelers are but one example; the traveler can be devastated by a pathogen that people native to the area harbor in their bodies with little or no effect. HIV-2 is carried in the bodies of African green monkeys with apparently little effect, but when it 'crossed over' to human beings the result was fatal.

A second exception to the rule that pathogens should do no harm is when the disease is carried and spread by a vector. When a disease is spread from human to human by another species, such as the mosquito, flea, or tick, and does not depend on human beings for its existence, reproduction, or transmission, the pathogen is under no selective pressure to spare human beings and can be as virulent as it likes. In fact, extensive multiplication in the human host might be beneficial, because it increases the likelihood of the vector picking it up and continuing the microbe's reproductive cycle. It might be even better for the host to be disabled if, for example, the host would be less able to protect itself from the vector. As we might expect, pathogens are generally very kind to vectors, generally causing them no harm whatsoever (Lapp 1994:25). What this means is that anything that human beings do to increase their exposure to vector-borne pathogens will increase their likelihood of contracting a deadly disease.

A third exception to the 'do no harm' rule is when a pathogen is spread by contaminated water or another external medium. For example, diarrheal diseases tend to be more virulent if they are spread by water systems and do not require person-to-person contact. The reason, suggested biologist Paul Ewald (1993:88), is that diseases that are spread by contaminated water lose nothing by incapacitating their host, but they gain a great deal by reproducing extensively in the host. Their large numbers make it more likely that they can contaminate water supplies through the washing of sheets or clothing or through bodily wastes. Thus human activities that create contaminated water supplies are likely to create more virulent forms of diarrheal diseases.

Finally, the fact that diseases are spread by vectors or external mediums suggests that the virulence of a disease is affected also by the ease of transmission: the easier a disease is to transmit, the more virulent it is likely to be, or, conversely, the more difficult a pathogen is to transmit, the less virulent it will be. If a disease is difficult to transmit, the microbe that can lurk in the body without harming it (thus allowing the host to survive until an opportunity arises to jump to another host) has a decided advantage over a microbe that quickly kills or disables its host. Thus chronic diseases such as tuberculosis can lie dormant for years without doing damage to the host, waiting for an opportunity first to infect the host and then to spread to another. However, reasoned Ewald, if the disease is easy to transmit, then it is under no selective pressure to spare the host. Diseases such as ebola, for example, reproduce so rapidly in the body, and infect virtually every organ, that anyone who comes into contact with any of the victim's bodily fluids is likely to contract the disease.

The notion that diseases that are difficult to transmit are likely to be less lethal has
important implications. For example, sexually transmitted diseases in generally monoga
mous populations should be less virulent, according to Ewald, because the pathogens
have to wait longer to be transmitted from host to host. If sexual activity increases, how
ever, it is to the pathogen's advantage to increase rapidly in the body to take advantage of
the increased likelihood of transmission. This seems to fit with some developments with
HIV, the virus that causes AIDS. In populations in which transmission was more difficult
because people had fewer sex partners or were more likely to use condoms, the disease
evolved into a less virulent form (Garrett 1994: 587).

Even if Ewald's hypothesis that diseases that are easier to transmit are more lethal

does not apply universally, its implications are striking. It means, as Ewald (1993:93) sug
gested, that we should be able to make a pathogen less lethal by increasing the price it

pays for transmission; in other words, by making the pathogen more difficult to transmit, we should be able to force it to evolve toward a less lethal form. Thus by cleaning up water supplies, protecting ourselves from mosquitoes, reducing the likelihood of the spread of sexually transmitted diseases, we are working not only to prevent the disease but to make it less deadly when it does occur.

Having examined how human actions bring us into contact with a pathogen and help determine how lethal it is, let's move on to the next step toward our death. Let's assume we have come into contact with a pathogen that is highly virulent to human beings. Is there anything that can save us? Fortunately, the human body has evolved a highly sophisticated immune system that generally prevents microbes from harming us. When a microbe infects the body, specific cells of the immune system, T cells, attach themselves to the invader, signaling other cells, macrophages, to envelop and destroy it. Once destroyed, other cells of the immune system call off the attack, lest the system overreact and destroy its own cells.

It is an ingenious system and, under stable conditions, one that will hold in check most microscopic invaders. However, if an immune system is weakened, for example by hunger, it is less able to fight off disease. Furthermore, in unstable conditions, when the opportunity exists for rapid changes in the number and type of microbes, the microbes have a decided advantage. Microbes are extremely adept at evolving ways to escape the body's immune system. The reason is that viruses and bacteria mutate and reproduce at a much faster rate than larger organisms such as human beings. Consequently, if a microbe evolves that can somehow get around the immune system, that particular variety of microbe will have a distinct adaptive advantage, and more of its offspring will survive. Ultimately this will lead to the emergence of a microbe for which our bodies have no defense.

Simple arithmetic demonstrates how quickly microbes can adapt to changed or threatening environments. Let's assume that a variety of an organismlet's call it X emerges with a characteristic that gives it only a 1 percent reproductive advantage over another varietyYof the same organism. That means that 101 of the X variety will survive in each generation to only 100 of Y. Arithmetically this means that X will become the dominant form of the organism in only thirty generations. In human terms thirty generations is a long time700-800 years. But for microorganisms thirty generations is a very short timefor bacteria that reproduce every twenty to thirty minutes, thirty generations can elapse in a day, at the end of which two bacteria have produced 1 billion.

Because of this ability to adapt so quickly, some microbes have developed the ability to evade the immune system. The bacterium that causes dengue hemorrhagic fever has evolved to use the immune system to spread from the blood systems to the vital organs. The virus that causes influenza changes so rapidly that infection by one strain does not confer any immunity to subsequent strains. The AIDS viruses evolved to attack and destroy the body's immune system, not only allowing the virus to survive and spread but creating the opportunity for other diseases, such as tuberculosis, to take root and thrive. In fact, one of the major threats of the HIV is that the rapid change in its genetic structure, about 1 percent per year in some varieties, will allow it to evolve resistance to whatever defenses the body or medical researchers may develop.

Assuming, then, that we have met a lethal pathogen and that the body's immune system is unable to destroy it, what next? As far as we know, human beings have always

sought to cure whatever illness afflicted them. Ritual and ceremonial cures are known in societies throughout the world, as are the use of plants and other natural resources. However, there is little question that one of the major success stories of the culture of capitalism is the development of measures to protect people from and cure them of infectious disease. The discoveries of the causes of infectious disease and then the development, manufacture, and distribution of vaccines and antibiotics has, in general, extended the human life span in societies throughout the world. Worldwide, life expectancy at birth was 48 years in 1955; 59 years in 1975; and 65 years in 1995 (World Health Organization 1997).

Unfortunately, just as microbes can quickly adapt and evade the natural defenses of our immune system, they can also quickly evolve to render modern drugs useless. When antibiotics are overused or used incorrectly or prescribed for viral infections against which they are useless, new varieties that are resistant to existing antibiotics may evolve. Some researchers claim that half of the 150 million antibiotic prescriptions written by American doctors each year are misprescribed or misused in this way. Patients take a portion of the prescribed dosage and, once they feel better, neglect to take the rest. This results in killing the bacteria most susceptible to the antibiotic but may leave unaffected those that are more resistant. Those resistant bacteria then gradually become the dominant strain of the microbe; even if 99.9 percent of the original strain is destroyed, the survivor is likely to be a superstrain on which existing antibiotics have no effect (Platt 1996:54).

Furthermore, half of the antibiotics used in the United States are used for livestock, aquaculture, and other biological industries. Monocultural farming is a major source of the problem. When only one kind of animal or one kind of crop is grown, a disease outbreak can decimate a business. A commercial chicken farm, for example, may have 100,000 chickens; an aquaculture facility may have thousands of salmon. To protect themselves, growers use antibiotics to fend off disease, creating an opportunity for evolution of drug-resistant strains of pathogens, some of which may be capable of infecting people.

Anne E. Platt (1996:52) summed up the problem when she wrote:

Today, almost all disease-causing bacteria are on the pathway to complete drug resistance. More than a half century after the discovery of antibiotics, humanity is at risk of losing these valuable weapons and reverting to the pre-antibiotic era.

One of the greatest risks we face may come from drug-resistant tuberculosis that is finding its way from poor countries to the rich. The most dangerous source for this disease is the former countries of the Soviet Union. Because of the economic collapse, prison doctors treating tuberculosis were unable to give a full course of drug treatments to patients. The partial treatment triggered the rise of a new dominant strain of the disease that was causing 10,000 new drug-resistant cases a year each 250 times more expensive to treat than the old strain of the disease. And tuberculosis spreads quickly. More than a dozen passengers on a flight from Paris to New York were infected by a lone Ukrainian infected with the drug-resistant strain (York 1999). Some estimate that, if it is not properly treated, 1 billion people will be newly infectedand 35 million will diein the next two decades.

Thus we get some idea of how human actions can influence the relationship between infectious pathogens and human bodies, and what it takes in a general sense for us

to die of an infectious disease. Next let's examine how this translates to the relationship between disease and culture, and more specifically, how people's behavior in the culture of capitalism contributes to the creation and transmission of infectious disease.

The Relationships between Culture and Disease

As we have seen, our world is filled with organisms that can cause us harm. Whether or not we come into contact with them, how deadly they are for us, and whether or not we can help the body fight them off or reach a mutually beneficial arrangement is greatly influenced by the kinds of lives we lead or, more specifically, the cultures and patterns of social relations that we construct, maintain, and reproduce. Let's examine this a little further and identify some of the specific cultural adaptations of human beings that either encourage or inhibit disease. One of the questions we want to consider is, how has the emergence of consumer capitalism influenced the spread of disease? Put another way, how does the behavior appropriate to our culture expose people to the risk of disease or create opportunities for the creation and spread of infectious pathogens? To illustrate the relationship between culture and disease, between our behavioral choices and how they affect our relationships with the world of microbes, let's examine what happened to disease during another great cultural transformation in human history, the shift from gathering and hunting to agriculture.

Gathering and Hunting to Early Agriculture

Early gathering and hunting societies were likely afflicted by a range of diseases far different from our own. Small, geographically scattered human populations did not afford infectious diseases the same opportunity for infection and transmission as do large, densely populated modern societies. Most pathogens in early human societies must have depended for their survival on nonhuman hosts. When they infected human beings it was when people got in the way of the reproductive cycle of the nonhuman host, not because the microbe depended on human beings for their survival.

Contact with wild animals likely exposed early human societies to such diseases as rabies, anthrax, salmonellosis, botulism, and tetanus (Cohen 1989:33). Worm parasites that infested animals' bodies would have been encountered by hunters. Malaria and yellow fever were transmitted by mosquitoes and other diseases by ticks. As Mark Cohen noted in Health and the Rise of Civilization (1989), these diseases strike rarely, cannot spread directly from person to person, and do not claim many victims. But since human beings would not have built up an immunity to these diseases, and since the offending microbes would not have depended on human transmission, the diseases were often fatal.

There were also categories of disease that could be transmitted from person to person; these would have had to live in hosts for a long time to have the opportunity to spread and must have been transmitted fairly easily by touch, breathing, sneezing, or coughing and in food or other shared items. Yaws was probably one such disease, as may have been the herpes virus and a variety of intestinal illness (Cohen 1989:37). Since diseases tend to

evolve toward less virulent forms the longer they coexist with a population, diseases that we recognize today as mild may have been more serious in earlier human populations.

However, it was during the transition of human societies from gatherers and hunters to sedentary agriculturists that began some 10,000 years ago that whole new relationships developed between culture and disease. By remaining sedentary people probably came into contact with fewer pathogens, and by remaining in one place people likely developed greater immunities to localized bacteria, viruses, and parasitic infection. Sedentariness also makes it easier to care for the sick. But, as Cohen pointed out, sedentariness also has some major disadvantages. First, sedentary societies are more likely to engage in longdistance trade, which may increase contact between groups and, as a consequence, spread disease from one group to another. Sedentary populations also create more favorable conditions for pathogens to spread; permanent shelters attract vermininsects and rodents that may carry disease, while the buildup of garbage and human waste may serve in sedentary societies to harbor and spread microbes, especially if water sources are infected with human waste.

Alteration of the landscape through horticulture, animal husbandry, and agriculture exposed people to new disease. Malaria-bearing mosquitoes would have thrived in the ponds and bodies of stagnant water created by human environmental intervention. Ponds and irrigation ditches would have provided opportunities for expansion of the snail that carries schistosomiasis.

Improvements in cooking technology, particularly pottery, may have helped cook food more thoroughly and destroyed disease-carrying microbes, but porous pots may have encouraged the growth of some bacteria. Storage of food for extended periods increased the possibility of bacteria buildup and fungal contamination and attracted disease-carrying vermin.

Finally, regular contact with domesticated animals exposed human populations to additional infections. Living in close contact with animals gives parasites such as the tapeworm an opportunity to involve human hosts in their life cycle as they pass between humans and domestic animals. There is evidence that most human respiratory disease arose after animals were domesticated, and a whole range of disease now common in human beingsmeasles, smallpox, influenza, and diphtheriaare thought to have their origins in domestic animals (Cohen 1989).

'Graveyards of Mankind'

Much as agriculture changed the relationship between microbes and humans, the voluntary or involuntary decisions of people to move to cities shifted the balance in favor of infectious disease. Simply put, the more people per square mile, the more easily an infectious agent could pass from one person to another. For example, as early as 2,000-4,000 years ago writers told of infestations of lice, bedbugs, and ticks that they associated with dense housing conditions and the onset of disease. The chances of a citizen of ancient Rome living to the age of thirty years was one in three, whereas 70 percent of rural residents survived until thirty (Garrett 1994:236). In 430 B.C. an epidemic of an unknown disease in Athens killed half the population.

But while cities have existed at least 6,000-7,000 years, they began increasing dramatically in size during the expansion of the capitalist world system, Cities became the hubs of financial activities and were themselves one of the main reasons for the growth of trade, city residents relying on food from rural agricultural areas and trade items from distant places. Cities also grew as a consequence of the commercialization or capitalization of agriculture, as more people were pushed off the land and forced to seek sustenance in the cities of the core and then the periphery.

Five diseases in particular seem to have benefited from the expansion of urban environmentsbubonic plague, leprosy (Hansen's disease), cholera, tuberculosis, and syphilis. Bubonic plague, as we saw in Chapter 3, was spread in the fourteenth century by traders and invaders from central Asia west into Europe and east into China and periodically reemerged, with disastrous demographic, economic, and social consequences. Cities tried to protect themselves by banning travelers from entering and by finding scapegoats on which to blame the disease. Tens of thousands of Jews and alleged devil worshippers were slaughtered for this reason, the city of Strasbourg alone killing 16,000 of its Jewish residents. The Brotherhood of Flagellants, a society of Christian men, beat themselves with leather straps embedded with iron spikes to drive out the sins they believed responsible for the disease (Garrett 1994:238). In 1665 the plague hit London, killing as many as 3,000 people per day.

Leprosy is a particularly good example of an apparent adaptation of a parasite. The disease swept over Europe in 1200, aided by the growing density of cities, disdain for bathing, wool clothing, and sharing of bedding with others to stay warm. The disease is caused by a bacterium passed by human contact that attacks the nerves of the extremities, causing them to go numb. Since there is no feeling in the fingers, toes, and other extremities, injuries go unnoticed by the victim, leading to the characteristic disfigurement and stigmatiza-tion of victims. By 1980, most of the world's five billion people had antibodies to the bacterium, indicating they had been harmlessly exposed to the disease (Garrett 1994:239).

Cholera struck the world's cities in four devastating pandemics between 1830 and 1896, spreading through contaminated water and sewage systems. In St. Louis in 1849 10 percent of the population perished; in the city of Mecca in 1847 some 15,000 residents and Muslim pilgrims died, and another 30,000 died in 1865; in London in 1847 53,000 died. Since the disease seemed to affect the most impoverished segments of the population, those in power assumed it was due to lower-class 'immorality.' It was not until 1849 that London physician John Snow demonstrated that the disease was transmitted via water supplies. Snow removed the handle of a pump that was the sole water supply for a cholera-ridden neighborhood, and the local epidemic ended. Yet it was years before authorities were convinced that the disease was transmitted through the water supply and took measures to protect it.

Tuberculosis was the most deadly disease of the nineteenth century. Like others, the bacterium responsible for the disease, Mycobacterium tuberculosis, was ancient, dating back to at least 5000 B.C. Tuberculosis is a slow-growing disease, causing illness only after months or years of infection and then ultimately killing the host; however, only about 10 percent of those infected actually develop the disease. It is transmitted through microscopic droplets exhaled by victims, making people who inhabit densely populated, closed spacesthe kind typical of urban slumsparticularly susceptible.

The effect of population density on the incidence of tuberculosis is evident in its history in the United States. In 1830, Boston had a crude death rate from tuberculosis of 21 per 1,000, half that of London, which has a far larger population. By 1850, when Boston's population had grown, the death rate was 38 per 1,000. In Massachusetts in general tuberculosis rates increased by 40 percent from 1834 to 1853. Then, toward the end of the nineteenth century, for unknown reasons, tuberculosis rates began to decline. In 1900, tuberculosis killed about 200 of every 100,000 Americans; by 1940, before the advent of antibiotic therapy, the rate was 60 per 100,000.

A number of hypotheses have been offered in the ensuing debate over why tuberculosis death rates declined. Some claim that better nutrition enabled people to withstand infection better. Rene Dubos, whose 1952 book The White Plague pioneered the study of the connection between human behavior and disease, claimed that the elimination of the deplorable working conditions of men, women, and children during the Industrial Revolution along with improved housing resulted in the decline.

Laurie Garrett (1994:244) suggested that a clue to the decline in tuberculosis can be found in the experience of South Africa. Even with the increased availability of antibiotics and an understanding of the transmission of the disease, death rates for tuberculosis rose 88 percent from 1938 to 1945. Cape Town saw a rise of 100 percent, Durban 172 percent, and Johannesburg 140 percent. Urban rates of infection were as high as 7 percent of the total population, while in rural areas, despite poverty and hunger, the rates were less than 1.4 percent. Virtually all cases struck the Black and Asian or 'colored' population.

Housing, according to Garrett (1994:245), seemed the most likely culprit responsible for the outbreak. During that period South Africa had its own industrial revolution and, as in Europe in the eighteenth and nineteenth centuries, required inexpensive labor. Blacks and colored, by far the major source of cheap labor, were required by law to live in areas designated by the government and to carry identity cards that stipulated where they could and could not go. The government subsidized housing for the White population, but government-sponsored housing projects for Blacks actually declined during this period of expansion by 471 percent, resulting in abysmal living conditions. The South African medical authorities blamed the outbreak on an imagined genetic susceptibility of Blacks, thus blaming the victim for an affliction caused by the expansion of the capitalist economy.

Cities also seemed to provide ideal conditions for the emergence of sexually transmitted diseases such as syphilis. The density of population, anonymity of urban life, and influx of single people, especially men, in search of work, promoted greater sexual activity, experimentation, and prostitution.

There is some debate over the origins of syphilis (see Baker and Armelagos 1988). It is carried by a bacterium transmitted in sexual intercourse or at birth from an infected woman to her child. It was first reported in Europe in 1495 among French soldiers (explaining its early designation as the 'French disease') fighting against Naples and within two years had spread throughout the world, apparently existing in a deadlier form than it does today. Since the outbreak of the disease coincided with the return of Columbus's sailors from the New World, many scholars believe its origin lay in the Americas, from which it was spread by European conquerors to the rest of the world. Others argue that the rate at which the disease killed indigenous people of the New World suggested a lack of any immunity that would likely have been conferred if the disease were native to that area

of the world. Still others (see Hudson 1965) suggest that syphilis is caused by the same bacterium that causes yaws, a common but easily cured childhood skin disease with a worldwide distribution, and that local sanitary conditions determined whether the disease manifested itself as yaws or syphilis. Regardless of its origins, it spread throughout European cities from the sixteenth through the twentieth centuries.

The pace of urbanization from the fifteenth to the nineteenth centuries that created conditions for diseases such as plague, leprosy, cholera, tuberculosis, and syphilis to spread has dramatically increased in the twentieth century, especially in the periphery. In 1950 there were only two megacitiesurban areas with ten million or more people New York and London. By 1980 there were ten: Buenos Aires, Rio de Janeiro, Sao Paulo, Mexico City, Los Angeles, New York, Beijing, Shanghai, Tokyo, and London. Currently 45 percent of the world's peoples live in cities of 2,000 or more (Population Reference Bureau 2000). Many of these urban dwellers will be new migrants from rural areas flocking to cities, as they have for centuries, in search of jobs, often after being forced off their land by the continuing concentration of agricultural production and wealth in a few hands and by government policies that function to create cheap labor to fuel economic growth. These densely packed populations will continue, as they have for centuries, to be prime breeding grounds for the creation and dissemination of disease.

When New York and London were reaching megacity status, they were doing so in countries that were the richest in the world. That wealth allowed them to adjust to their growth by building sanitation services, public health networks, and medical services to accommodate not only growing numbers of people but the special problems created by increasing population density. The new megacities, with the exception of some in East Asia, for the most part lack that luxury. Not only have they grown at unprecedented rates, but they are in countries on the brink of economic ruin. The international debt of countries such as Brazil, Egypt, Mexico, and India prevents them from building facilities to accommodate the growing urban populations. Residents live in hastily constructed shantytowns and slums that rival any of those in eighteenth- and nineteenth-century Europe and America for the extent of poverty and disease. Even the richer cities cannot keep up with the growth; in Tokyo in 1985 less than 40 percent of dwellings were connected to proper sewage, and tons of untreated human waste was dumped into the ocean. Hong Kong, another of the more wealthy cities, was dumping one million tons of untreated waste each day into the China Sea. In the poor cities, of course, the situation is far worse. In 1980, 88 percent of Manila's population lived in squatter settlements with houses built of scrap wood, cardboard, tin, or bamboo. Nairobi's slums, where 40 percent of the population lived, were deliberately left off official maps of the city (Garrett 1994:251).

A United Nations report reveals that the average child growing up in one of the urban slums of the periphery is forty times more likely to die before her or his fifth birthday of a preventable infectious disease than a rural child in the same country. No country is immune; the extent of neglect of inner city children in the United States was underscored in 1993 when the World Health Organization announced that the United States had fallen behind Albania, Mexico, and China in childhood vaccination rates, largely because of the collapse of health services to inner city poor (Garrett 1994:512).

Human demographic patterns, largely a consequence of labor movement and commerce, therefore, continue to generate environments that not only harbor pathogens and

provide ample opportunity for their spread but also help opportunistic pathogens expand their base of operations. A case in point is cysticercosis, a disease produced by tapeworms found in undercooked pork and other animal flesh, which in some forms can infect the brain. Epidemiologists observed that in Mexico City people were being infected not from eating undercooked porkthose infected could not afford to eat meatbut from the water of the Tula River, highly polluted and the city's primary water source. Tens of thousands of people living in shantytowns downriver from the city's sewage system were being infected. Once a parasite adapts to a new environment, it may easily spread. By 1980 this pathogen had found its way to Los Angeles, carried back by a traveler to Mexico, immigrants, or visitors to the United States.

Diseases of Environmental Change

Urban centers emerged as a natural outgrowth of the expansion of commerce, increased industrialization, and the need for financial hubs to serve as links between commercial and industrial centers. However, the environmental and social changes of the past fifty years that have influenced the spread of disease have been more methodical and controlled. We carefully plan and build massive hydroelectric projects that result in the flooding of millions of acres, in the process creating new environments for water-borne infectious parasites. We methodically destroy millions of acres of rainforests, in the process creating new habitats to be exploited by disease vectors. We plan and build roads that bring people into areas where they have never been, thus exposing them to new pathogens. We expand habitats, consequently changing the delicate ecological balances and promoting evolution of microbes that once infected only nonhuman species to infect human beings. We knowingly dump raw sewage into our oceans and waterways, not only spreading disease worldwide but creating a massive evolutionary medium for new pathogens to develop. In modern warfare we devastate environments in ways that past armies were incapable of doing, in the process creating opportunity for pathogens to thrive.

For example, in 1985 the Daima Dam was built on the Senegal River by the Maurita-nian, Senegalese, and Malian governments. The dam made possible the irrigation of 10,000 hectares of desert soil, converting it into fields of sugarcane, potatoes, mint, and rice. As a result of agricultural expansion, a few members of a local tribe became millionaires (Platt 1996:45). But with the dam came infectious disease. Sanitation in the area is poor, and the irrigation canals, from which people drink, bathe, and wash their clothes, have become infected with strains of diarrheal bacteria. The dam also halted the flow of saltwater that once penetrated up to 200 kilometers inland. The salt water had kept the snail population in check, but the dam created ideal conditions for an epidemic of snail-borne schistosomiasis. The first cases were detected in 1988, and by 1990 60 percent of the population exhibited symptoms. In one village that had profited from growing mint, 91 percent of the people were infected.

Schistosomiasis is an ancient disease. Egyptian mummies have evidence of infection and the disease was common in China around 200 B.C. during a time of expanding rice cultivation. Today it ranks second only to malaria among diseases in tropical regions. It infects farmers and fishers who wade in shallow water infected with the snails that carry the disease. It is transmitted when people defecate the larvae of the parasite, which then travels through water supplies and infects other snails and people (Platt 1996:47).

In some areas the disease is so prevalent that it goes unrecognized. Katherine A. Dettwyler (1994:46) was doing anthropological work on disease in Mali and taking urine samples; she received one from a young boy that appeared to be full of blood. The urine contained over 500 Schistosoma eggs per milliliter, the highest count measurable with the technique she used. When she gave him a look of consternation, he asked, 'What's the matter?' 'Does your urine always look like this?' she asked. 'Yes,' he replied, 'Isn't it supposed to? Doesn't everyone's?' She later learned that in some communities the first appearance of red urine in boys was believed to be equivalent to the onset of menstruation in girls and was thought to indicate sexual maturity. In some communities celebratory rites of passage were held when boys reached this milestone.

When Brazil completed its highway through the Amazon a new disease, oropouche, began to strike residents of Belm; it affected 11,000 people. It seems that when settlers cleared the forest for cacao planting, they disturbed the habitat of a midge that harbored the virus that caused the disease. Discarded cacao shells provided a new breeding ground for the insect, and the explosion of their population in association with human settlements created the opportunity for disease spread.

One reason forest, especially rainforest, destruction unleashes disease is because of the variety of species that exist in forests. A single hectare of rainforest contains more insect species than the entire New England area or all of Great Britain. When human beings destroy that habitat, it brings them into contact with insects and pathogens that are then searching for new habitats and new hosts.

Dengue is an example of how new, more deadly diseases can emerge as a consequence of environmental damage and population movement. Dengue is a virus, a cousin of the yellow fever microbe and generally spread by the female Aedes aegypti mosquito. In any one of its four forms dengue was not life-threatening, and it had virtually disappeared by 1950 after worldwide campaigns to eradicate the carrier mosquito. But in 1953 a new variant, dengue-2, struck in Manila in the Philippines. Dengue-2, or dengue hemorrhagic fever, was far worse than any of the other forms of the disease, causing internal hemorrhaging, shock, and soaring fevers. In 1958 it hit Bangkok, Thailand, infecting 2,297 people, mostly children, and killing 240; within 5 years 10,367 people were infected and 694 had died.

Researchers discovered two clues to the origins of the disease: first, it was carried by A. aegypti; second, all of the victims had at some time been exposed to one of the milder forms of dengue. While the earlier disease did no damage, the immune systems of those afflicted had created antibodies to the disease. The researchers discovered that dengue-2 had developed a remarkable method to use those antibodies to its own advantage. As mentioned earlier, when a foreign body enters the human bloodstream, antibodies attach themselves to it, largely to identify it for other parts of the immune system that will then attack and destroy it. Antibodies attached themselves to the dengue-2 virus, signaling the mac-rophage cells to envelop the invading microbe and destroy it. But the dengue-2 virus had developed the ability to take over the immune system's primary killer cells, not only allowing it to evade the immune system's response but also giving it access to every organ of the body, producing fevers as high as 107F, convulsions, shock, and death.

Dengue-2 spread through East and South Asia with ever-expanding populations of A. aegypti and Aedes albopictus, better known as the tiger mosquito, probably named for its aggressive behavior. The disease spread to the Americas, likely in ships carrying the

mosquitoes. When mosquito abatement programs were cut in various countries to reduce government expenses, an opportunity was created for the disease to spread. Dengue-2 made its appearance in 1981 in Havana, Cuba, where an epidemic that raged for 6 months caused 340,000 illnesses and 158 deaths.

The Cuban epidemic sent Shockwaves through the U.S. public health community, because in 1980 two residents of Laredo, Texas, had developed dengue hemorrhagic fever. In 1982 an epidemic in New Delhi, India, sickened 20 percent of the population, and by 1990 the disease would be endemic in Latin America. To make matters worse, a shipment of used tires from Japan to Houston, Texas, for retreading contained tiger mosquitoes, creating the likelihood of this aggressive mosquito invading urban environments and outcompeting the less aggressive mosquito. Unlike A. aegypti, which feeds only on humans, the tiger mosquito feeds on virtually any animal, raising the possibility that it can harbor and transmit viruses from other animals.

The question is, what led to the creation of dengue hemorrhagic fever? Tom Monath of the Centers for Disease Control and Prevention in Atlanta, Georgia, examined historical and laboratory evidence and concluded that World War II was responsible (see Garrett 1994: 257). He surmised that the massive bombings, the population movements and dislocations, and wartime disruptions of mosquito abatement programs resulted in a surge in the population of A. aegypti. Then rapid troop movements brought into the Philippines people who, perhaps without knowing it, had been infected by one of the existing dengue varieties. American troops who arrived may already have been to dengue-infested areas such as Burma, Thailand, Indonesia, the Pacific Islands, and China. Thus all four varieties of dengue, each adapted to its specific environment, were brought together in one place and rapidly passed between people and mosquitoes, creating the cycle necessary for the ultimate mutation of one variety into dengue-2. The expansion of commercial travel and possibly the Korean and Vietnam Wars created further opportunities for cross-fertilization and spread of the disease to the slums of Latin America.

By 1981, when dengue-2 hit Havana, it had become an annual feature of the urban Philippines. There, when the mosquitoes emerged in full force after every rainy season, dengue-2 arrived like clockwork, infecting tens of thousands of children and killing 15 percent of those infected. Nonexistent before World War II, by 1980 dengue-2 was one of the major childhood killers in Asia.

The kinds of connections operative in the creation of dengue hemorrhagic fever, between microbes, disease vectors such as mosquitoes, and the movement and activities of human beings, can be enormously complex. New outbreaks of cholera in the 1990s involved not only microbes, vectors, and human beings but also such diverse events as global warming, the spread of oceanic algae, breakdown of sanitation, and the eating habits of the people of Peru. Dengue-2 also provides an example of the interconnected-ness of people in the creation and transmission of disease.

Much of the pollution that human beings pour into the oceansraw sewage, fertilizers, pesticides, and other chemical wasteserves as nutrients for algae blooms, thus increasing their size and frequency. Researchers discovered in the 1970s that cholera vibrio, which they labeled El Tor, could live inside algae, taking a form that allowed it to lie in a dormant state for weeks, months, and perhaps years. It was further discovered that El Tor is immune to a whole range of antibiotics.

El Tor is common in South Asia, particularly off the coast of Bangladesh. It is believed to have been picked up in algae by a Chinese freighter, which then dumped the cholera-carrying algae off the coast of Lima, Peru. The vibrio then infected shellfish in the area. The shellfish was used in making ceviche, mixed raw fish and shellfish in lime juice, a national delicacy of Peru. The ocean waters carried the algae up and down the South American coast, and by the end of 1991 cholera had struck at least 336,554 people, killing 3,538. By 1993 at least 900,000 people were reported infected, and 8,000 died. Tests showed that the cholera recovered from patients was identical to that in the algae.

In 1992 a whole new strain of cholera emerged off the coast of India. Dubbed Bengal cholera, it was unaffected by the antigens developed by the immune systems of people afflicted with either classical cholera or El Tor, thus leaving everyone open to reinfection.

Scientists trying to determine the cause of the outbreaks and the reason for the emergence of new strains of cholera hypothesized that algae blooms have exploded in size and frequency, fed by nutrients from fertilizer, garbage, and fecal waste incubated in the hotter waters resulting from global warming. The expanded algae blooms become giant floating gene pools in which bacteria, viruses, algae, and terrestrial microbes from human waste and runoff float around, possibly mutating rapidly because of the increased ultraviolet radiation caused by the damage from industrial pollutants to the atmosphere. The algae spread rapidly to different parts of the world, bringing new and more deadly variants of disease (Garrett 1994:563-567).

Anne E. Platt, in Infecting Ourselves, outlines many of the social, political, and economic activities that result in higher risks for infectious disease (see Table 8.2).

AIDS and the Culture of Capitalism

We mentioned earlier that AIDS is very much the signature disease of our age. By this we mean the conditions for its development and spread were essentially created by our patterns of beliefs, attitudes, and behaviors. AIDS burst upon the world in 1981, when physicians in San Francisco and New York began to encounter symptoms in young men that either had been seen previously in older men or were so rare most physicians had never seen them. They turned out to be opportunistic infections, such as rare forms of pneumonia, cancer, and other diseases that attacked bodies whose immune systems had been destroyed. The new disease was first called gay-related immunodeficiency disease (GRID) because of its early diagnosis among gay men, but when it was acknowledged to occur in heterosexual populations the name was changed in 1982 to acquired autoimmune-deficiency syndrome (AIDS). In 1983 the disease appeared in Zaire, and some European researchers thought they had unearthed cases in European hospitals as early as 1967, and possibly 1959.

The early 1980s was a turbulent time for AIDS. Researchers were competing to be the first to isolate and identify the virus. Researchers in Europe and Africa could not publish their articles in the leading medical journals because the peer review panels did not believe the disease was transmitted heterosexually and claimed the researchers had missed some other mode of transmission. The Reagan administration, which had made

TABLE 8.2 Causes of Infectious Disease Emergence and Representative Disease Examples

Cause of Emergence

Infectious Disease

Changing environmental conditions

Deforestation

Agriculture and irrigation

Dam building, road building Poor sanitation and hygiene

Climate change

Demographic changes Urbanization

Increased trade, travel, migration

Deteriorating social conditions

Breakdown in public health

services

War and civil disorder Increased sexual activity

Intravenous drug use Overuse of antibiotics

Other

Air conditioning systems

Ultra-absorbent tampons

Unknown

Malaria, hemorrhagic fever, rabies, Lyme disease

Argentine hemorrhagic fever, Japanese encephalitis, Bolivian hemorrhagic fever, schistosomiasis, influenza (pandemic)

Schistosomiasis, malaria, Rift Valley fever

Diarrheal diseases, malaria, schistosomiasis, lymphatic filariasis, river blindness, dengue, yellow fever, cholera, Guinea worm disease, Japanese encephalitis, salmonella, hemolytic uremic syndrome, cryptosporidiosis, giardiasis

Hanta virus, plague, malaria, schistosomiasis, other vectorborne disease

Yellow fever, malaria, dengue, acute respiratory illness, plague, cholera

Cholera, yellow fever, influenza, dengue, dengue hemorrhagic fever, pneumonia, HIV/AIDS, influenza

Measles, diphtheria, pertussis, tuberculosis, cholera, influenza, HIV/AIDS, other sexually transmitted diseases

Malaria, cholera, diphtheria, waterborne diseases

Hepatitis B and C, HIV/AIDS, other sexually transmitted diseases

HIV/AIDS

Antibiotic-resistant malaria, tuberculosis, staphylococci, pneumococci, enterococci, gonorrhea, others

Legionnaire's disease Toxic shock syndrome Streptococcus Group A, ebola

From Anne E. Platt. Infecting Ourselves: How Environmental and Social Disruption Trigger Disease. Washington, DC: Worldwatch Institute, 1996. With permission.

millions of dollars available for research in Legionnaires' disease, was reluctant to release funds for AIDS research, education, and services. Leaders of the religious right in the United States opposed using federal funds for a disease they claimed was God's judgment against immorality and corruption. Pat Robertson, a Baptist minister, founder of the Christian Broadcasting Network, and presidential candidate in 1988, claimed scientists were 'frankly lying' when they said AIDS could be spread heterosexually and that condoms would prevent infection. In the meantime, AIDS continued to spread among heterosexuals, gay men, intravenous drug users, and hemophiliacs given HlV-infected transfusions (Garrett 1994:469).

As of 2000, an estimated 13-17 million people have died from AIDS since the epidemic began and the Joint United Nation Program on HIV/AIDS (UNAIDS) and the World Health Organization (WHO) estimate that there are presently 36.1 million people worldwide infected with HIV/AIDS (see Table 8.3). Sub-Saharan Africa has the highest

TABLE 8.3 Regional HIV/AIDS Statistics and Features at the End of 2000

IDU = intravenous drug use; MSM = males who have sex with males.

Source: data from UNAIDS 2000, https://www.unaids.org/wac/2000/wad00/files/WAD_epidemic_report.htm.

rate with 25.3 million infected, or 8.8% of the population, while Eastern Europe and South and Southeast Asia have the fastest rate of growth. In North America there have been 1-2 million cases of HIV. This total is heavily skewed toward the poorest segments of the population; in 1995 the incidence of AIDS was 6.5 times greater for Blacks and 4.0 times greater for Hispanics than for Whites.

We now think we know the origin of AIDS, that it likely crossed over from nonhuman primates in central and west Africa sometime after World War II, infecting only a few people until the late 1970s, when it made its breakthrough worldwide. But there are many questions we need to explore to understand the effects of human culture on the disease. For example, what features of global culture influenced the spread of the disease? What features of our culture determined the people most at risk for AIDS? How did our culture influence the way people choose to react to the epidemic and those affected by it?

How Did the Disease Spread?

AIDS reveals the extent to which we are interconnected in global space. We live in a world, as geographer Peter Gould (1993:66-69) noted, in which New York is closer to San Francisco than it is to towns 200 miles away; in which Los Angeles is closer to Miami and Houston than it is to towns in Nevada; in which Kinshasa, Zaire, is closer to Paris than to villages in the center of the country. Gould meant by this that people located at the hubs of the capitalist world system, those cities connected by rapid air travel, are more likely to come into contact with each other than they are with people located spa-cially much closer to them. Viewed another way, patterns of contact are characterized by what Gould called 'hierarchical diffusion' rather than 'spacially contiguous diffusion.' In the hierarchical diffusion that characterizes AIDS, or 'AIDS space,' as Gould called it, the disease jumps from travel hub to travel hub.

This is not the first time global space has been redefined by revolutions in trade and travel. In the earlier eras of sea travel seaports became economic hubs as well as the major points of distribution for disease. Today, with rapid air travel, economic centers such as Tokyo, New York, Paris, Jakarta, San Francisco, London, Sao Paulo, Bombay, Johannesburg, and Moscow form the geographic center of the world system and, as a consequence, the epicenters of the spread of AIDS.

With the exception of infected blood supplies, AIDS has to be carried from place to place by people and transmitted directly. There is no vector involved in AIDS as in plague, malaria, or dengue. But human travel provides an effective means of transmission. Therefore, to understand the spread of AIDS, we need to ask why in the culture of capitalism do people travel? Generally they travel for one of four reasons: tourism, business, labor migration, and war, all of which have had a major role in the spread and distribution of AIDS.

Tourism is essentially a product of industrial capitalism of the nineteenth century. While the wealthy of Europe had their country estates and cottages for centuries, travel and tourism were relatively new phenomena for the emerging middle class (Hobsbawm 1975:203). Made possible by the development of steamboats and railways, the tourist industry grew throughout the nineteenth and early twentieth centuries. For the British middle class holiday travel became a serious enterprise in the 1860s and 1870s; this transformed

Advertisements for sex tours, such as this one for Thailand, attract tourists from Europe, North America, and other parts of Asia and create fertile breeding grounds for the AIDS virus and other sexually transmitted diseases.

the British coastlines with promenades and piers. In Europe mountain resorts, such as Biarritz, were becoming fashionable. Tours through Europe became popular, creating an industry and a form of travel that was probably unique. For the poor, day trips dominated; American resorts such as Coney Island in New York became popular for new immigrants to the United States. In the twentieth century tourism evolved into a major industry, and few people, certainly in the core, have not at one time or another been tourists. Tourism is one of the world's largest industries with tremendous annual growth rates. The industry's gains grew to $439 billion dollars in 1998 (Pera and McLaren 1999).

Tourism has always been associated with disease, as any traveler can tell you who has sampled food and water laden with bacteria to which his or her system had no resistance. It is likely that such perils have confronted travelers for centuries. But in the age of AIDS it is not only the traveler who is at risk; the people in the host country are equally susceptible.

We have no figures on the number of people who have contracted AIDS as a consequence of tourist travel, but researchers suggest that it has had a major impact on at least two countries hardest hit by the epidemic, Haiti and Thailand. One reason for their susceptibility is that both were targeted for 'sex tours.'

Anthropologist and physician Paul Farmer (1992) suggested that the history of HIV/AIDS in Haiti is linked to its history as a tourist destination. In the 1970s, Haiti, the poorest country in the Western Hemisphere, became a major tourist attraction with the closing of Cuba in 1959 to American tourists. Tourist visits to Haiti increased to 100,000 per year by 1970 and 143,538 by 1979. (Later, the tourist industry was a casualty of the Haitian AIDS epidemic: tourist visits dropped to 75,000 in the winter of 1981-1982 and under 10,000 the following winter.)

Tourism in Haiti brought with it an increase in institutionalized prostitution. Poverty and 60-80 percent unemployment rates made prostitution for males and females one of the only economic alternatives available. The country, particularly the Carrefour area of the capital city Port-au-Prince, gained a reputation for cheap sex. Travel guides published for homosexual men recommended Haiti to tourists.

Whether AIDS was brought to Haiti by American tourists, as some researchers suggest, or in some other fashion is a matter of debate, but it is clear that tourism accelerated the spread of the disease among Haitians and, probably, among tourists. By the late 1980s the rate of HIV in hotel workers catering to tourists was 12 percent, and Haiti had one of the highest rates of infection in the world. But even when Haitian workers became aware of AIDS, they seemed to treat it as just an 'occupational hazard' (Farmer 1992:145).

In Thailand, also, tourism played a major role in the spread of AIDS. HIV/AIDS was relatively late in arriving in Asia, with the first recorded death in 1984, a gay man who had spent time in the United States. By 1987 the rate climbed in months from 15 percent to 43 percent among intravenous drugs users. The group hit hardest by AIDS was the commercial sex workers. Among Chiang Mai prostitutes the rate of infection went from 0.04 percent in 1989 to 70 percent 20 months later (Garrett 1994:489).

Thailand had for years an active trade in both drugs and prostitution, trades that accelerated when Thailand became a major rest and recreation zone for American military personnel during the Vietnam War. Both drugs and prostitution were, and continue to be, major sources of foreign exchange for Thailand's economy. By 1990, Thailand was attracting 5.3 million tourists a year, with a high proportion of single men from Malaysia, Japan, and Taiwan and with special 'sex tours' arriving in Bangkok from Japan, the Middle East, and Europe, particularly Germany. As a consequence of the growth in the sex industry, there are 500,000-800,000 prostitutes representing some 10 percent of the female population between the ages of fifteen and twenty-four. In some areas of Bangkok in the early 1990s there was an AIDS infection rate of 90 percent.

Probably because of the economic importance of the sex industry, particularly for attracting tourists, government authorities in Thailand were slow to respond to the threatened epidemic. As cases began to increase in 1987, the government decided not to launch an anti-AlDS campaign for fear of 'inciting panic.' By 1989, 0.5 percent of all pregnant women were HIV-seropositive, with some northern provinces reporting rates of 3 percent. In 1991 the government reevaluated its policy and noted again that they did not want to create panic. A Bangkok newspaper reported that HIV/AIDS was spread only by anal sex and intravenous drug use, when in fact there were forty times more heterosexual cases than homosexual cases reported. The World Health Organization estimated that by 1992, 450,000 people in Thailand were infected.

Another form of travel that characterizes the capitalist culture is labor migration. At least since the increase in slave trade in the seventeenth and eighteenth centuries, the world economy has required massive shifts of laborers from one area to another. While it is difficult to determine exactly the extent of the worldwide transmission of AIDS by migrating workers, there is considerable evidence that this type of travel was a major cause of AIDS transmission in Africa. Male workers travel from rural areas to urban areas in search of work, sometimes visiting prostitutes whose infection rate in some areas approach 90 percent and sometimes bringing the disease back to their rural villages.

Commercial and business travel were also instrumental in the spread of AIDS. The routes of infection in Africa travel along well-traveled truck and commercial transportation routes. The north-south alignment of AIDS starts at Djibouti at the mouth of the Red Sea, the port city and railway terminal for the city of Addis Ababa, the capital of Ethiopia, to which goods, and AIDS, flow. In 1991 some 50-60 percent of prostitutes and 1 percent

of the general population were reported infected with HIV. In the Sudan 80 percent of the 'bar girls' were seropositive for HIV-1. From Uganda to Mozambique, samples of truck drivers indicate that 30-80 percent are infected. Estimates are that Tanzania has 1.4 million infected people of a total population of 18 million, Zimbabwe has 1.5 million, and Kenya 1.6 million. The highway between Malawi and Durban, South Africa, is known as the 'Highway of Death,' truckers having an infection rate of 90 percent (Gould 1993:75).

Patterns of AIDS distribution seem to follow commercial routes in North America as well. Paul Farmer (1992:149) noted that the incidence of AIDS in the Caribbean correlates with the degree to which a country is economically integrated into the 'West Atlantic system.' Excluding Puerto Rico because it is not an independent country, the countries with the highest rates of AIDSthe Dominican Republic, the Bahamas, Trinidad/Tobago, Mexico, and Haitiare also the countries most dependent on trade with the United States and most linked to the American economy. The country with the highest rates of AIDSHaitiwas most dependent on U.S. exports.

Finally, the movement of soldiers and refugees precipitated by conflict played a role in the spread of AIDS. Researchers speculating about the origins of AIDS and the factors that may have contributed to its breakout in central and East Africa have concluded that something dramatic must have happened around 1975 to cause the emergence of the epidemic. The period of 1970-1975 was characterized by guerrilla warfare, civil war, tribal conflicts, mass refugee migrations, and striking dictatorial atrocities. Laurie Garrett suggested that such social upheaval may have affected the course of AIDS both directly and indirectly. For example, most African conflict was characterized by rival forces trying to cripple each other economically, politically, socially, spiritually, and militarily. In such conflicts, civilian casualties are high. In any number of military campaigns of the past two to three decades in central Africa rape was used (as it was in Bosnia) systematically to terrorize and dominate the enemy. Some armies have tested up to 50 percent HIV-positive. Other human activities resulting from social disruption, including increased multiple partner sexual activity, famine and malnutrition that further stressed immune systems, large-scale migrations and concentrations of people in refugee camps, increased prostitution, and destruction of health care services, could have further spread the disease (Garrett 1994:367-368).

Who Gets Infected with AIDS?

Rene Dubos (1968) wrote in the 1950s and 1960s of the special vulnerability of the poor to infections; malnutrition, substandard housing, dense population, and lack of access to health care all promote the spread of infectious disease. Paul Farmer in Infections and Inequality (1999) documents the link between economic inequality and susceptibility to infectious disease. Certainly poverty played a role in the spread of tuberculosis, cholera, and syphilis. But AIDS has affected not only the economically marginalized but also those who are socially and politically marginalizedhomosexuals, women, and children. Public and governmental responses to the AIDS epidemic, especially in the United States, was greatly influenced by the mistaken assumption that it was a disease of homosexual men, in spite of the fact that there was clear evidence of heterosexual transmission in the United States, Europe, and particularly Africa, where it was almost exclusively

Women, particularly in Africa, comprise the majority of AIDS victims.

transmitted by heterosexual relations. We may never know to what extent the association of the disease with a socially marginalized portion of American society delayed research and education efforts, but it is clear that it didn't help.

It is also clear that the poor, globally and in the United States, have been the most frequent victims of the disease. Africa, the poorest area of the world, has by far the highest incidence of AIDS, while Eastern Europe, economically devastated with the collapse of socialist economies and cutbacks in health services, has the highest rate of growth in HIV/AIDS. Poor countries in other areas of the world are the others most affected. For a particularly apt illustration of a poor and socially marginalized country that suffers disproportionately with AIDS, let's return to Haiti.

Haiti itself is very much a creation of the capitalist world system. In the sixteenth and seventeenth centuries the indigenous population (the Taino) were exterminated and the country resettled with African slaves ruled by a European elite. Haiti passed from Spain to France in 1697 and was renamed Saint-Dominique. In 1804 a slave revolt led by Toussaint L'Ouverture succeeded in defeating the French, establishing the country of Haiti, the first, as Paul Farmer referred to it, of the Third World countries.

The new country found itself in a world hostile to the idea of self-governing Blacks, a nightmare to every country in which slavery endured, particularly the United States. Every effort was made to undermine Black rule in Haiti. The French demanded that Haiti compensate planters for the loss of land, and periodically in the nineteenth century European gunboats would appear in Haitian ports demanding compensation. By 1900, 80 percent of

national revenue was going to pay off international debts, and by the late 1920s Haiti was being advertised in Financial America as a place where 'easily directed' Haitian labor could be had for 200 per day, as opposed to $3 per day in Panama.

American domination has continued throughout the twentieth century, as Haiti has lived with a series of despotic rulers supported by the United States. This history left Haiti in 1983 with an annual per capita income of $315 overall and $100 in the countryside. The agricultural situation was so bad that Haiti was a net importer of food, even sugar. Even when Haiti had promise as a recreational playground for other North Americans, the tourist industry collapsed because of Haiti's reputation as the originator of AIDS. There were few avenues out of poverty in Haiti. The 60 percent unemployment rate combined with the country's dependence on the United States set the stage for what Farmer (1992:189-190) called the 'West Atlantic pandemic.'

AIDS is not only a marker of poverty, it is becoming a marker of gender and age as well. We saw in our discussion of famine and hunger that women and children are particularly at risk. In the instance of AIDS, women worldwide represent the majority of all reported cases. The fact that women, who were at the fringe of the epidemic in the mid-1980s, have frequently become victims reflects the role of women in global capitalist culture. Women seem to become infected at a younger age; in many countries 60 percent of new AIDS infections are among women between the ages of fifteen and twenty-four; in surveys of several African and Asian countries, women under twenty-five account for 30 percent of new AIDS cases, compared to 15 percent for men under twenty-five.

Women contract the disease largely through heterosexual intercourse; many of these are among women who are monogamous but have male partners who are not. This is due in part to the sexual subordination of women in many countries where men initiate sexual relations and women, especially wives, have little say. The attitudes toward women and sex in many countries inhibits conversation about sexual matters and virtually prohibits AIDS educational campaigns directed toward women. Furthermore, education is hampered by the higher illiteracy rates among women in many countries. Even in countries with well-developed campaigns to educate women about the risk of AIDS, men still often resist condom use because of decreased sensitivity, ignorance about how to use them, or fear that their use will cause sterility.

Women also contract the disease through prostitution, itself a reflection of the limited options available to women, especially in poor countries. As Laurie Garrett (1994:368) said about AIDS and prostitution in Uganda,

[a]s a business, prostitution was second only to the black market. For most women there were only two choices in life: have babies and grow food without assistance from men, livestock, or machinery, or exchange sex for money at black-market rates.

Finally, the more women are infected with AIDS, the more likely children will be infected. Children are at risk of acquiring the disease at birth. AIDS can be transmitted by infected hypodermic needles; yet, many countries that depend on intravenous drugs are too poor to afford new needles. In some African countries needles are reused. Intravenous transmission of AIDS to children is not solely a problem of the periphery. In Russia, the collapse of communism and the social and economic chaos that followed virtually de-

stroyed the country's health care system. Syringes were unavailable, and medical personnel, especially in rural areas, were forced to use the same syringes again and again, up to four hundred times in some cases. In 1988 AIDS emerged in Elistya, capital of the Kalmyk Republic on the Caspian Sea. A baby had been infected by its mother. The baby was treated by staff who used the same syringes to draw blood samples and administer drugs to all the babies in the hospital's nursery for three months; HIV was unknowingly injected into all the babies on the ward and some of their mothers (Garrett 1994:501).

Socially marginalized members of the capitalist world system face another danger: once infected with HIV they are the ones least likely to receive treatment or to receive information to enable them to take measures to avoid the onset of AIDS. As AIDS researcher Rene Sabatier (cited Garrett 1994:475) noted in reference to AIDS education campaigns,

I think there is a very real danger that we're going to end up as a [world] society divided between those who were able to inform themselves first and those who were informed late. Those who have access to information and health care, and those who don't. Those who are able to change, and those who aren't. I think there is a real danger of half of us turning into AIDS voyeurs, standing around watching others die.

The announcement in the summer of 1996 of a new drug treatment that restores the body's immune system and holds the AIDS virus at bay is a further development in the ghettoization of AIDS. While the announcement was greeted with great enthusiasm, and the use of the drug has cut mortality rates in the United States by 75 percent, the treatment costs at least $10,000-20,000 per year and is therefore beyond the reach of the world's poor. When South Africa moved to make generic versions of HIV/AIDS drugs, or proposed importing the drugs from countries with the lowest prices, actions that could have helped cut the costs 50 percent-90 percent, the United States raised objections and drug companies sued, although, under heavy public pressure, withdrew the threats. Drugs, however, remain largely unavailable to the poor. Of the one million people in Malawi who are HIV positive, only 30 are on the new drug therapy (Finkel 2000).

Who Gets Blamed?

We saw the phenomenon of blaming the victim when we examined population growth, poverty, hunger, and environmental degradation. Problems generated by core exploitation of the periphery are blamed on the periphery itself. However, nowhere is the phenomenon of blaming the victim more clearly illustrated than in the case of HIV/AIDS, and nowhere was that more clear than in the case of Haiti. When the AIDS epidemic was identified in the early 1980s, Haitians with AIDS were a 'wild card': they didn't fit the categories of homosexuals, hemophiliacs, and heroin users. So they were added as a whole category, thus completing the early four-H club (homosexuals, hemophiliacs, heroin users, and Haitians). But this was clearly racist: there was no reason, based on some thirty-four cases, to place all Haitians in a risk group. This would be analagous to claiming that all San Franciscans or all New Yorkers were at special risk to contract and spread the disease. Risk designation was akin to being labeled a carrier. Then, in a leap that surprised few Haitians, AIDS was said to have originated in Haiti.

Bruce Chabner of the National Cancer Institute was quoted in 1982 as saying, 'Homosexuals in New York take vacations in Haiti, and we suspect that this may be an epidemic Haitian virus that was brought back to the homosexual population in the United States' (cited in Farmer 1992: 201). This epidemic of blame led to widespread discrimination against Haitians in job hiring and a rapid decline in the Haitian tourist industry.

The Haitian government was angry with the Centers for Disease Control (CDC) because, even when it became evident that the rate of infection was higher in other Caribbean Islands and most U.S. cities, the CDC refused to abandoned the designation of Haitians as a high-risk group. In 1985 the CDC finally removed the designation but without comment, refusing to admit it made an error. Then in 1990, the FDA ruled that Haitians could not donate blood. It was an absurd ruling; as one Boston newspaper editorial pointed out, if the FDA was consistent it would have banned donations from all San Franciscans, New Yorkers, Bostonians, and emigrants from other Caribbean Islands, some of whom had rates of AIDS/HIV as much as ten times greater than Haiti's (see Farmer 1992; 220).

Why was Haiti singled out? Largely, according to Paul Farmer, because the U.S. folk model of Haitians included images of superstitious natives, Blacks, immigrants, and the like that symbolized the stigma associated with AIDS. The model was driven to some extent by the media. The New York Times wrote that 'Haitian voodooists may be unsuspectingly infected with AIDS by ingestion, inhalation, or dermal contact with contaminated ritual substances, as well as by sexual activity' (cited Farmer 1992:3). This view was furthered by the medical community. Jeffrey Viera, senior author of the paper that put Haitians at risk, blamed the media for stigmatizing Haitians, but he himself made reference to voodoo rituals, the drinking of menstrual blood, and the like. An article in the Journal of the American Medical Association entitled 'Night of the Living Dead' considered these voodoo origin theories, asking whether necromantic zombies transmit HTLV-III/LAV (Farmer 1992:3). Blaming Haiti for AIDS was a classic case of blaming the victim.

The view from the periphery concerning the origins of AIDS was quite different than the view from the core. As researchers focused on Africa as the origin of the disease, African officials became sensitive to what they saw as a Western campaign to blame their countries for the epidemic. One result was official government denials that there was any AIDS in African countries, even after the epidemic had clearly become established. One African health minister was fired after admitting to international health agencies that AIDS was present in his country. Not surprisingly, conspiracy theories abounded. One theory was that the American CIA had introduced the disease; another, popular also in core countries, was that AIDS was the result of American germ warfare experiments gone awry.

Haitians saw AIDS as a disease visited on them by resentful Americans. As one Haitian school teacher (cited Farmer 1992:232) put it, 'The Americans have always resented Haiti, ever since 1804. Being strong, they can punish us, humiliate us. The AIDS thing was a perfect tool.'

Haitian teenagers in the United States, when asked if they thought the United States did what they did on purpose, almost universally said yes. Others said that AIDS was created in U.S. laboratories.

Paul Farmer (1992:58), in AIDS and Accusation, concluded that questions asked by Haitians and Americans such as

Is AIDS a product of North American imperialism? Can one person send an AIDS death to another through sorcery? Are Haitians a special AIDS risk group? Are 'boat people' disease-ridden and a risk to the health of U.S. citizens?underscore several of the West Atlantic pandemic's central dynamicsblame, search for accountability, accusation, and racismthat have shaped both responses to AIDS and the epidemiology of a new virus.

Conclusion

The disease factors that we examined in this chapter have practical consequences. For example, knowledge of the effects of culturally defined human behavior can help us predict as well as treat disease. Might more careful application of this principal have made a difference? Could we have anticipated the emergence of AIDS, as many medical anthropologists once posited? Would we have let multidrug-resistant tuberculosis get out of hand? Would we have allowed so many antibiotic-resistant strains of disease to develop or relied so much on antibiotics? Would drug-resistant malaria be out of control? Would new diseases such as Lyme disease spread so quickly?

Even if we were to predict, as some scientists did, the dangers of overuse of antibiotics and other things, could we really have done something about it? Even knowing the dangers of AIDS, the U.S. government moved slowly in releasing research funds. Even when it was known that anal sex was responsible for AIDS, many in the homosexual community refused to heed advice for safe sex, believing AIDS was just a scare tactic to discredit their life style.

We continue to create 'disease sinks,' populations of poor and marginalized people among whom infectious pathogens thrive and who may serve as breeding grounds for new diseases. If there was some omnipotent microbe responsible for the survival and spread of all infectious pathogens, it could hardly improve on the actions of human beings in the culture of capitalism whose cumulative behavioral choices relegate some of their numbers to these sinks.

The lesson is that while we must be aware of how our behavior puts us in danger of contracting disease, we must also be aware of the factors that promote adoption or rejection of therapeutic regimes necessary to lower our risk of becoming ill, cure us, or inhibit the creation of new and more deadly strains of disease. If biologist Paul Ewald is correct and diseases become more lethal the more easily they are spread, then given the increase in travel, the increase in the number of poor, the cutback of medical and public health services for structural adjustment programs, the ecological destruction of habitats such as rainforests, and the emergence of drug-resistant strains of new and old killers, we are truly on the verge of a pandemic on a scale of that which struck the peoples of North and South America in the sixteenth and seventeenth centuries.

What can be done? That is difficult to say, but it seems that political, religious, and social associations that can marshal forces against largely imaginary social, political, and religious enemies certainly could rally populations to cope with the pathogens that threaten to overwhelm us.