The Doctor Will See You Now

by Cory Franklin

  Both the public and private sectors will require procedures providing oversight when somebody can no longer do their job. Currently that function is filled by mandatory retirement policies. In places like Congress where there is no mandatory retirement age, Strom Thurmond and his associates can stay on far longer than they should. But in many large corporations, mandatory retirement is simply a necessary but blunt instrument designed to permit the company to anticipate future personnel costs. It doesn’t always identify the workers incapable of functioning effectively and often works perversely the other way. Many people now reaching mandatory retirement age between fifty-five and sixty-five are healthier than those of past generations, still able to do their jobs, and unable to transfer their skills to other occupations once they are retired.

  Enter the medical profession—physicians, psychologists, social workers, and other professionals specializing in neurologic and occupational evaluation. They will play an important role in the future, not only as caregivers but also as consultants to business and government, expert witnesses in lawsuits, and as go-betweens to mediate disputes between workers who want to remain in their positions and employers wanting to let them go.

  These medical professionals will have a host of new evaluation tools at their disposal—an emerging array of new imaging scanners of the central nervous system, individual genetic information, and evolving research on the diverse and often-unpredictable patterns of aging. Their collective judgment will play an integral role in American society as the baby boomers leave the workforce.

  William Shakespeare described the tragedy of the impaired elderly as they exit the public stage in one of the supreme works in the English language, King Lear. The old and once-powerful king, in “the infirmity of his age,” divided his kingdom unwisely—an incomprehensible act no one was willing to challenge. This fateful decision ultimately led to war in his kingdom, his death, and that of his children.

  A preferable real-life model, sans tragedy, is that of famous American essayist Ralph Waldo Emerson, who developed severe dementia in his late sixties and could no longer write or lecture. In neurologist Oliver Sacks’s bestseller Musicophilia, he described how Emerson retained his sense of irony and humor. When asked how he felt, even in his state of advanced dementia, Emerson would smile and answer, “Quite well; I have lost my mental faculties but am perfectly well.” For those who can no longer pursue their lives’ work, assuring retirement at the right time and making sure they are happy should be the goal of an enlightened society.

  VI

  PAST EPIDEMICS AND FUTURE THREATS

  51

  WHEN THE CLIMATE CHANGES, SO DOES HEALTH

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  Almost daily and in every part of the world, new health hazards arise from modern technology. Some of these hazards make an immutable public impact. . . . Others attract less attention because they lack the drama and are not obvious in their effects. . . . Such is the case for the dangers posed by certain pollutants of air, water and food, which remain almost unnoticed despite their potential importance for public health. . . . Hardly anything is known of the delayed effects of pollutants on human life, even though they probably constitute the most important threats to health in the long run.

  —RENÉ JULES DUBOS

  WHEN RENÉ JULES DUBOS, a professor of tropical medicine at Harvard and a Pulitzer Prize winner, wrote those words in 1965, the world had never heard of the terms global warming and climate change. Today, with climate change a prominent political, social, and scientific issue, it behooves us to pay heed to the warning Dubos issued nearly fifty years ago. Future policy debates should incorporate the potential effects and future likelihood of the international health consequences of global climate change.

  When it comes to the health of individuals and societies, the relationship between man and nature has always been a tenuous one. Massive plagues and epidemics have devastated entire societies and have continually changed the course of history. Disease played a prominent role in the Peloponnesian War, striking down nearly a third of the population of Periclean Athens (including Pericles himself) during its war with Sparta in 429 BC. In the Middle Ages, the black death (bubonic plague) killed off one-third of the population of Europe.

  The sixteenth-century Spanish conquest of Mexico by Hernán Cortés, which changed the face of Mesoamerica, may not have been possible had it not been for a smallpox epidemic that killed thousands of Aztec warriors during the battle in 1520 for the Aztec capital, Tenochtitlan. In the last century, an influenza epidemic at the end of World War I took as many as thirty million or more lives throughout the world in one year, far more than all the combat casualties of the actual war itself. Since the 1970s, AIDS has been an international scourge, killing millions, and even today millions of people die every year of AIDS and other communicable diseases on the African and Asian subcontinents.

  Nor are infectious diseases the only natural disasters to have killed millions and radically altered societal patterns. The European Little Ice Age of the thirteenth and fourteenth centuries was devastating to the indigenous inhabitants of northern Europe and caused mass migrations across the continent. China has historically been afflicted with terrible river flooding, which has killed millions over the centuries. Drought, a natural calamity in much of central Africa and Australia, has periodically decimated and displaced entire populations of those continents.

  Today the world faces another potential threat—the adverse health consequences of climate change and global warming. At the outset it should be noted that the climate variability that may result in a warmer world in the next century is certainly the way global temperatures are trending, but there is no uniform agreement about how quickly or how much the Earth will warm (a difference of even one degree Celsius would change factors such as insect-vector spread). Further, the debate extends to how much of that warming is the direct result of rising concentrations of atmospheric greenhouse gases due to the burning of fossil fuels and other human activities (scientific estimates range from a slight contribution to over 100 percent, the latter suggesting the Earth would otherwise be cooling). Finally, there is debate as to what measures should be taken—primarily an economic and political, rather than a scientific issue.

  What is clear is that the Earth’s surface temperatures have been warming steadily for the past eight decades (coincident with rising carbon dioxide concentrations), although there is a suggestion that the warming trend, while continuing to rise, may have slowed slightly in the last decade (this is according to the Goddard Institute for Space Studies and Climate Research Unit). If the warming trend of the current generation does continue unabated in the next century, it presents a number of serious potential health consequences. Anticipating these health risks will allow us to take action to prevent the catastrophic social, demographic, and economic upheaval that could result worldwide.

  Because climate is such a complex phenomenon, it is difficult to predict precisely how climatic changes could affect human health. Moreover, all the changes may not be adverse; some may even be beneficial—for example, the health effects of milder winters in some areas might mitigate some of the effects of hotter summers in others. Assuming overall warmer temperatures worldwide, there will be associated changes in precipitation, humidity, and wind patterns. We can anticipate the concomitant health effects as likely to fall into three categories: increases in extreme weather events, infectious diseases primarily due to water and insect transmission, and changes in the ecosystem that affect food supply. Not surprisingly the most profound effects of all these would probably be seen in the world’s poorer populations.

  Extreme Weather Events

  Climate change is often misunderstood to mean simply warming of the environment. Weather variability—that is, shifts in day-to-day conditions—is also a possible consequence of climate change. Even a small increase in mean temperatures in the coming decades, if accompanied by an increase in the variability of weather patterns, could result in a rise
in the frequency of extremely hot days to dangerous levels. (Consider what would happen in Chicago if the average summer high temperature, currently 85 degrees, increased almost imperceptibly to 87, but the number of days at least five degrees higher than average doubled from the current eighteen. Instead of eighteen days with temperatures above 90 degrees, there would now be thirty-six days with temperatures above 92. Dangerous heat waves would become a routine occurrence.) An increased number of heat waves could pose a serious threat to many countries, especially those where populations are aging and moving to urban areas.

  Currently, roughly half the world’s population is located in cities, but by 2030 this figure is expected to increase to 60 percent. Because of roads, buildings, and industry, large cities tend to be “heat islands” that can reach temperatures ten to twelve degrees higher than the surrounding countryside (in Chicago, Lake Michigan modifies this effect). The Chicago heat wave of 1995 killed over seven hundred people, and a 2003 heat wave in southern France may have killed as many as fifteen thousand people, with mortality occurring primarily in the elderly, the infirm, and those socially isolated. It is not clear that either of these heat events was the result of global warming; both could have been isolated weather events. Nevertheless they illustrate the devastating potential for heat-related mortality in future extreme weather events.

  Besides heat-related mortality, climate change poses the threat of deaths from the increased frequency and severity of storms, especially hurricanes in the Atlantic, typhoons in the Pacific, and cyclones in the Indian Ocean, as well as smaller-scale storms such as tornadoes in the American Midwest. Deaths from flooding, wind damage, and waterborne disease are all potential consequences. Hurricane Katrina in 2006, a storm that was an isolated weather event and probably not a consequence of global warming, did immense damage as a result of its strike over a populated land mass and the resultant storm surge. Global predictive models are still not sophisticated enough to forecast the likelihood of similar future storms, but the threat, while uncertain, remains real.

  Infectious Diseases

  Even a mild increase in temperatures, especially in the tropics, will increase the incidence and seasonal transmission of various infectious diseases by extending the geographic range of vector hosts such as insects, ticks, and water snails. These disease carriers are the intermediate hosts for a number of serious conditions, including malaria, Lyme disease, sleeping sickness, yellow fever, viral encephalitis, and West African river blindness.

  Malaria is a case in point. Mathematical models have demonstrated that changes in rainfall patterns and temperature could allow the mosquitoes that transmit the disease to flourish and drastically increase the number of people exposed in endemic areas of Africa. Malaria was common in Europe in the nineteenth century and was still seen in southern Europe as recently as the 1950s. It is conceivable that, with climate change, the European continent could see a recurrence, especially if the mosquito vector demonstrates resistance to the insecticides currently used for control.

  After a period of decline in the middle of the last century, African sleeping sickness, trypanosomiasis, now kills forty thousand people in central Africa annually. A warming of less than five degrees (Fahrenheit) would permit the tsetse fly, the insect vector, to disperse southward. Were the fly able to extend its geographical boundary as far south as South Africa, the disease could threaten the large livestock reserves and population centers of that country. Another potential infectious disease threat is cholera, which can be rapidly fatal in its most severe forms and is currently found in Asia, Africa, South America, Central America, and Mexico. There were several serious cholera outbreaks in the United States in the nineteenth century. The causative organism may be harbored in oceanic coastal waters, and some believe that if sea surface temperatures were to increase, the bacterium would proliferate, causing major cholera epidemics worldwide.

  Food Supply

  Changes in precipitation patterns and temperature could have a profound effect on regional food yields and water supplies (imagine the implications if climate change caused a dislocation of the abundant midwestern American corn and soybean production several hundred miles north to southern Canada). Any shifts in food production would be unpredictable, but in some areas, drought and heat would likely result in widespread malnutrition and contaminated water supplies. Diseases like tuberculosis and typhoid could become endemic. Refugees from affected areas would flood toward areas with more food, cleaner and more accessible water, and better opportunities for employment. It is not hard to imagine population migration scenarios resulting in the increased spread of disease and even the possibility of armed conflicts.

  Nor would the problem be confined to land-based agriculture. Countries such as Japan that depend primarily on fish as their dietary staple might be affected by changes in fluctuations in ocean temperatures. Changes in ocean currents and the warmth of the water could change the locations where fish reside. Moreover, there is some evidence that these factors would also increase the uptake of pollutants like mercury in the fish that constitute a vital part of the food chain.

  There are a host of uncertainties about whether the worst effects of climate change and global warming will actually occur. Despite the most complicated mathematical models currently available, the future remains a mystery. But even if a mild degree of global warming should take place over the next generation, the possibility of the aforementioned effects on human health suggests certain strategies to mitigate or avoid worst-case scenarios.

  Every scientific discipline has a role. Epidemiologists should be concentrating on case surveillance for serious infectious diseases while the public health community strengthens public health defenses and adopts strategies such as mosquito control and netting campaigns. Meanwhile, medical scientists must develop new vaccines and prevention campaigns for serious infectious diseases. Plant biologists must work on developing new crops resistant to drought and disease while meteorologists work on more precise models to predict severe weather events such as hurricanes and heat waves. Local and national governments should be involved in issues such as water conservation and purification, as well as measures to protect their citizens in the event of health emergencies.

  Ironically, René Dubos was prescient in articulating the threat to human health from the delayed effects of pollutants long before the current concern about climate change. So perhaps it is not surprising that Dubos, who almost certainly knew nothing of the issue of global warming, is credited by many as the original author of one of the famous maxims that still applies to the debate—“Think globally, act locally.”

  52

  ZIKA: THE LATEST EXOTIC TRAVELER TO STIR UP TROUBLE

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  Variability is the law of life, and as no two faces are the same, so no two bodies are alike, and no two individuals react alike and behave alike under abnormal conditions which we know as disease.

  —SIR WILLIAM OSLER, MD

  IN ANCIENT TIMES, bacteria and viruses could not travel between different countries and regions faster than humans could migrate on foot. Distant populations were relatively safe from foreign diseases. The transmissibility of disease expanded tremendously when travel by horse, and then ship, became common.

  With the twentieth-century development of intercontinental jet travel, global trade, tourism, and human migration, the “new normal” is epidemics and exotic diseases that can travel faster, farther, and in larger numbers than ever before in history. Witness the mosquito-borne Zika virus, which was barely on the World Health Organization’s radar and then suddenly ravaged South America, with thousands infected.

  Zika infection is usually not life threatening; however, it may occasionally be associated with the severe neurological condition Guillain-Barre syndrome. And health officials now believe Zika has a connection to microcephaly, a birth defect that can lead to severe brain damage. An alarming number of women who contracted Zika while pregnant have delivered babies with microcephaly. T
here is currently no vaccine or cure for Zika infection.

  Readiness is everything. Recall that a Dallas hospital, as a result of bureaucracy and inadequate preparation, misdiagnosed the first case of Ebola virus in the United States in a patient traveling from Liberia. The infected patient was released from the hospital but returned three days later, and by then it was too late. He subsequently died. Two nurses who had contact with him contracted the virus, and nearly 150 people had to be monitored for six weeks. Fortunately, Ebola is not easily transmissible; otherwise the situation could easily have been disastrous.

  The history of the Western Hemisphere is replete with examples of deadly contagions brought from distant parts of the world. While most transmission of exotic diseases today is from less developed countries to more developed ones, it was not always so. In the Middle Ages, smallpox was unknown to the Native American tribes. Ships with the first European settlers brought the disease, killing a large percentage of Native Americans in what is now the United States and Canada. Smallpox was also critical to the Spanish conquest of the Aztec and Inca empires of Mexico and South America.