Texte partiel :
Epidemics that quickly wipe out large segments of communities are rare in the U.S. these days. But before the 20th century, such disasters occurred quite frequently, ravaging bewildered populations who usually had little understanding of the causes. Apart from the human tragedies these episodes produced, some had lasting political effects on the nation. A dramatic example arose in 1793, when one of the earliest significant epidemics of yellow fever in the U.S. struck Philadelphia, then the nation's capital.
At the time, Philadelphia was the country's largest and most cosmopolitan city. Yet prominence and prosperity offered little protection. Over the summer and fall, roughly a tenth of its population, some 5,000 people, perished.
The trouble began soon after French refugees from a bloody slave rebellion in Saint Domingue (now Haiti) landed on the the banks of the Delaware River, which bounds the east side of the city. ln addition to news of the fighting, the refugees relayed tales of a mysterious pestilential fever decimating several islands in the West Indies. In July the same disease broke out in Philadelphia.
The first to fall were working-class people living along the Delaware. They suffered high fevers and hemorrhages; their eyes and skin turned yellow; and they brought up black vomit. Many died from internal bleeding within days of becoming ill.
These early victims escaped notice by leaders of the medical establishment, perhaps because of their location (both geographic and social) on the margins of the city. By August 19, however, a prominent physician named Benjamin Rush had been several similar cases and concluded that the patients suffered from "bilious remitting yellow fever". Rush, then in his late 40s, had encountered this malady once before, during his apprenticeship. He immediately warned that an epidemic was under way and took steps to combat it.
Rush stood in good position to influence the city's response to the disaster. He was a renowned professor at the University of Pennsylvania and a founder of the prestigious College of Physicians of Philadelphia. He was famous as a patriot and a signer of the Declaration of Independence, in addition to being a philanthropist and teacher. He was also possessed of enormous energy and a forceful personality.
At Rush's urging, Philadelphia's mayor Matthew Clarkson, asked the College of Physicians to recommend public health measures against the fever. It issued its report, drafted by Rush, on August 26. Following the : prevailing theory that the disease was contagious and spread by putrid vapors, the college told citizens to avoid people stricken with the disease, to breathe through cloths soaked with camphor or vinegar and to burn gunpowder to clear the air. It also proposed establishing a hospital to treat indigent victims, who were too poor to pay for the home care most people preferred. To avoid alarming the public further the college called for the silencing of church bells, which had been ringing incessantly to announce the many funerals in the city.
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Girard was familiar with yellow fever trough trading in the West Indies. He persuaded the mayor's committee to hire the physician Jean Devèze, one of the refugees from Saint Domingue. Devèze has treated the disease while in the French army and would become the world's leading authority on the condition. He advocated the so-called French method of therapy: bed rest, cleanliness, wine and treatment with Peruvian bark (a source of quinine, which is now use to treat malaria, not yellow fever). At Bush Hill, Girard generously supplied the wine from his own cellar.
Controversy over Treatments
American physicians objected to Devèze's appointment, however and four resigned from the hospital. In part, they may have been angry at losing medical authority over Bush Hill. Also, they were trained in the Scottish and English tradition, which was quite different from that of the French. Indeed, Devèze stood at the opposite pole from Rush and his supporters in what became a raging controversy over the best therapy.
In accordance with traditional teachings, Rush and many of his contemporaries believed the body contained four humors (blood, phlegm, black biìe and yellow bile). They therefore aimed to treat most illnesses by restoring balance to the body-through giving laxatives and emetics (to cause vomiting), drawing blood and inducing sweating.
Early on, Rush had become convinced that a combination of these treatments could effect a cureÑspecifically, he favored bleeding combined with delivery of a mercury-based mixture of calomel and jalap. "I preferred frequent and small, to Iarge bleedings in the beginning of September", he wrote in a 1794 account of the epidemic, "but toward the height and close of the epidemic", but toward the height and close of the epidemic, I saw no inconvenience from the loss of a pint, and even 20 ounces of blood at a time. I drew from many persons 70 and 80 ounces in five days, and from a few, a much larger quantity".
Over time, Rush became increasingly dogmatic. He claimed he "did not lose a single patient" who had been bled seven times or more. He also mounted a strenuous campaign, in private correspondence and in letters to the editors, urging doctors not to spare the lancet. His letters fiercely criticized physicians who seemed to pay lip service to the benefits of venisection but were more restrained than him in its practice. He aimed particularly strong invective at Devèze and the few other doctors who thought that radical bloodletting was dangerous and said so openly.
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Historians know that neither Rush's method nor Devèze's could have cured patients. With or without intervention, yellow fever runs a variable course, killing some but sparing others. As is true of most viral diseases, it remains essentially untreatable today, and therapy mainly consists of keeping patients comfortable and preventing dehydration. Devèze's gentle approach certainly did less harm than Rush's and may have helped patients remain strong enough to combat the virus. But it would be unfair to judge Rush for his decisions. His protocol was simply an aggressive version of a conventional therapy based on the medical theories of the day.
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After reappearing many times, yellow fever gradually subsided in the U.S. late ln the 19th century. It nonetheless contlnues to threaten certain tropical areas, particularly in South America and sub- Saharan Africa.
The decline in the U.S. began long before an effective vaccine was introduced ln the 1930s. (The vaccine is available or soldiers and travelers; unfortunately, it costs too much for populations living in the areas most prone to epidemics to day). Quarantine measures and municipal water supplies that reduced breeding areas for mosquitos probably played a role in ending the U.S. epidemics, but other factors, such as improved sanitation, must have been at work as well. The drop-off is part of a larger pattern in which death rates from many infectious diseases fell in the course of the 1800s.
In tropical regions, the virus finds a natural reservoir in monkeys, and there is no hope of eliminating it by destroying its natural hosts. Scientists may eventually be able to control the disease by displacing the native mosquito populatlon with genetically altered forms that cannot spread the disease, but that approach is far from realization. Meanwhile a yellow fever epidemic remains a worrisome possibility ln the U.S., particularly in the Deep South, where large populations of A. aegypti are found.
In spite of modern knowledge and the existence of a vaccine, such an epidemic could grow quickly. Once it began, public health workers would need time to immunize populations at risk and to establish effective mosquito control and quarantine measures. The U.S. Institute of Medicine has estimated that an outbreak of yellow fever in a major city, such as New Orleans, would potentially result in as many as 100,000 cases and 10,000 deaths.
The Institute has additionally predicted that yet unknown viruses could also become major health threats. (HIV, the virus that causes AIDS, is an example of a once obscure virus that triggered a major epidemic.) It has therefore urged the government to adopt better methods or identifying new outbreaks of infectious diseases, to stop them early. After their experience with the 1793 yellow fever epidemic in Philadelphia, Benjamin Rush and his medical colleagues would have firmly agreed.