Twelve Diseases That Changed Our World

Cholera is a horrible disease. At first, the symptoms produce no more than a surprised look as the bowels empty without any warning. In the 19th century, quarantine involved the inspection of ships, cargo, and passengers for evidence of contagious diseases. Inspections were conducted at an offshore quarantine station where ships were berthed and the passengers were examined for cholera, typhus, smallpox, leprosy, yellow fever, and plague. The federal quarantine was to be for 20 days but would apply only to steerage immigrant passengers, and not cabin passengers, even if they originated from the same cholera-ridden port. In 1892 a prominent New York physician said, “The history of every cholera epidemic in this country has proven that the disease entered our port on account of defective quarantine and it has been carried to us mainly by filthy immigrants.” To treat the violent diarrhea of cholera, health authorities in Germany, England, and France recommended a variety of nostrums and quack remedies: vinegar, camphor, wine, horseradish, mint, mustard plaster, leeches, bloodletting, laudanum, calomel, steam baths, and hot baths. Today, oral rehydration treatment (ORT) involves oral or intravenous administration of a solution containing glucose, sodium chloride, potassium, and lactate. It has been claimed that pollution, especially sewage, has ended more lives than smallpox and bubonic plague. Cholera, the most feared of all these sewage-related diseases, has provoked global horror and terror.

In the 1850s, Koch, Pasteur, and their microbe-hunting cohorts, armed with a disease-causing theory as well as microscopes with improved powers of magnification, began searching for agents that might be the cause of plague epidemics. During the past two millennia, there have been three great bubonic plague pandemics. These resulted in social and economic upheavals unmatched by those due to armed conflicts or any other infectious disease. One of the plague pandemics, called the plague of Justinian, came to the Mediterranean from an original focus in northeastern India or via Central Africa. The buboes continue to enlarge, sometimes reaching the size of a hen’s egg, and when they burst there is agonizing pain. Death can occur 2 to 4 days after the onset of symptoms. However, in some cases the bacteria enter the bloodstream. The second form of the disease, which may occur without the development of buboes, is called septicemic plague and is characterized by fever, chills, headache, malaise, and massive hemorrhaging, leading to death. As with humans, the disease in fleas has a distinctive pattern. More than 80 different species of fleas are involved as plague vectors. Plague is endemic in many countries in Africa, the former Soviet Union, and the Americas.

Tuberculosis (TB) is an ancient disease that has plagued humans throughout recorded history and even earlier. TB of the lungs is the most familiar form of the disease, giving rise to the slang word “lunger.” When localized to the lungs, TB can run an acute course, causing extensive destruction of lung tissue in a few months—so-called galloping consumption. TB can affect organs other than the lungs, including the intestine and larynx; sometimes the lymph nodes in the neck are affected, producing a swelling called scrofula. The word “tuberculosis” refers to the fact that the disease causes characteristic small knots or nodules called “tubercles” in the lungs. Franciscus Sylvius first described these in 1650; he also described their evolution into what he called lung ulcers. To the Victorians, the blood in the sputum blended metaphorically with menstrual blood, and so in a strange way sickness and death were blended with eroticism and procreation. Mycobacterium tuberculosis and M. avium are human pathogens that cause lung disease. M. avium causes opportunistic infections in immunocompromised people (e.g., those with AIDS); its symptoms can include weight loss, fevers, chills, night sweats, abdominal pains, diarrhea, and overall weakness. Coughing, pallor, spitting of blood, night sweats, and painful breathing signify that the disease is active. The lesion becomes infiltrated with lymphocytes and macrophages, and a delayed hypersensitivity reaction, similar to that experienced with a bee sting, occurs. Today it is recognized that tuberculosis is an infectious and a societal disease.

In September 1793, the federal government was forced to shut down when six clerks in the Treasury Department contracted yellow fever, five others fled to New York, and three workers in the post office and seven officers in the Customs Service became ill. Alexander Hamilton, who at the time was the Secretary of the Treasury, came down with yellow fever and left Philadelphia, but after being refused entry into New York City he and his wife traveled to Green Bush in upstate New York to stay with his wife's father. Yellow fever came to be known as Bronze John or the Saffron Scourge because of its telltale symptom: jaundice. Fear of the Saffron Scourge drove many people from the coastal communities, and those who could afford to do so left the South during what was called the summer "sickly season." Yellow fever did not occur in winter in parts of the American South where winters were cold and frosty. Perhaps most importantly, at the time no one knew what caused yellow fever or how to stop its spread. In one area 15 mosquitoes that had previously bitten yellow fever patients were released and allowed to bite volunteers; volunteers on the other side of the screening were not exposed to mosquitoes. The building of the Panama Canal was seriously affected by the problems of mosquito-borne disease, principally yellow fever. The last fatal case of yellow fever occurred in Panama in 1906.

Two laboratories—one in France headed by Luc Montagnier and one at the National Institutes of Health in the United States headed by Robert Gallo—identified a virus that was named human T-cell lymphotropic virus (HTLV) III by Gallo and lymphadenopathy virus (LAV) by Montagnier. The virus was found in tissues of patients with AIDS. Today both are recognized to be the same virus. The virus was renamed human immunodeficiency virus (HIV), and the disease complex it produced was called acquired immunodeficiency disease syndrome (AIDS). HIV is able to cause AIDS because it can infect and destroy the white blood cells critical to the normal functioning of the immune system. In addition, severe athlete’s foot and white patches on the tongue, due to Epstein-Barr virus, can occur. Once these symptoms appear, the person is said to have AIDS-related complex (ARC). HIV-2 is less pathogenic than HIV-1, and individuals infected with HIV-2 are less at risk for developing AIDS. The most commonly used drug, azidothymidine (AZT), delays the onset of AIDS by inhibiting viral multiplication. The modern plague of AIDS will continue to rise in the coming years as a result of infections that have already occurred, and it will decimate the ranks of the young men and women who are in their most productive years. Today, the modern plague of AIDS is a forceful reminder that the global impact of infectious disease is yet to be blunted.