Plague

For centuries past, plague was the scourge of the earth, killing at least an estimated 163 million people during three major worldwide pandemics. Today, plague still exists in the world although the number of cases and deaths is much lower. Plague still infects several thousand people a year and kills several hundred. Most cases are in southern Africa, Asia, and central South America.

Plague is an infectious disease that affects animals and humans. It is caused by the bacterium Yersinia pestis and is usually found in rodents and their fleas. When released into the air, the bacterium can survive for up to an hour. People usually contract the disease after being bitten by an infected flea or after handling an infected animal. To reduce the risk of death, antibiotics must be given within 24 hours after the first symptoms occur.

There are three types of plague and they can occur separately or in combination. The types are:

• Bubonic plague, the most common form of the disease. It does not spread from person to person but is transmitted when an infected flea bites a person or when material contaminated with the bacterium enters through a cut in a person's skin. Symptoms include swollen lymph glands, fever, headache, chills, and weakness.
• Pneumonic plague, which infects a person through the lungs. It can be spread in the air from person to person. Symptoms include fever, headache, weakness, shortness of breath, chest pain, cough, and pneumonia.
• Septicemic plague, which occur when plague bacteria multiply in the blood. It can occur by itself or be a complication of pneumonic or bubonic plague. It is not spread from person to person. Symptoms include fever, chills, exhaustion, abdominal pain, shock, and bleeding into the skin and other organs.

To reduce the chance of death, people with plague must receive antibiotics within 24 hours after the first symptoms appear. Effective antibiotics include streptomycin, gentamicin, and tetracycline. Early treatment allows most people with plague to be cured if diagnosed in time. There is no vaccine against plague available.

From 1954 to 1997, there were 80,613 reported plague cases in 38 countries, of which 6,587 people died, according to the World Health Organization (WHO). The highest number of cases, 6,004, occurred in 1967, and the lowest number, 200, occurred in 1981. These numbers likely represent only about a third of the actual number of cases, due to inadequate surveillance and reporting methods, according to WHO.

Plague has been around since the dawn of civilization and probably existed in animals before humans inhabited the earth. The first recorded plague epidemic occurred in 1320 BC and is described by its symptoms in the Bible (I Samuel, V and VI). It is not known how many people were infected. The first known pandemic, or severe worldwide epidemic, occurred in Asia, Africa, and Europe between 542 and 546 AD. It was named Justinian's plague, after the emperor of the Byzantine Empire at the time, and killed an estimated 50 million to 100 million people.

The first pandemic is believed to have started in Egypt, spreading north through the eastern Mediterranean. The plague struck at a critical time. In Constantinople, the capital of the Byzantine empire, Justinian and his generals were in the midst of battles to rejoin Byzantium to the remains of Western Roman Empire. Justinian's dream was to reestablish the former Roman Empire; and he might have succeeded if not for the plague. Procopius, a historian living in Constantinople at the time, vividly described the plague and its effects. His writings also include an accurate description of what would later be called the bubonic plague. He wrote about agitated, feverish disease victims with painfully enlarged lymph nodes (buboes) under their arms and in their groins. According to Procopius, 300,000 people died within the city alone. It is impossible to verify whether that figure is accurate, but it is certain that the plague had a dramatic effect on history. Justinian's plans to re-establish the Roman Empire were very likely derailed because of the loss of manpower. In the west, the remnants of the Western Roman Empire collapsed into the Dark Ages.

Following the initial outbreak in 542, the plague disappeared and reappeared at intervals over the next 200 years. The years 542 to 600 were the most intense plagues years, but local epidemics flared up throughout the Mediterranean region through the mid-eighth century. The population of Europe wasn't able to recover between outbreaks and some historians estimate that the population dropped by half between 542 and 700. After the late-eighth century, plague disappeared from Europe for nearly 600 years.

The second pandemic is the infamous "Black Death" from 1347 to 1350 AD.It killed from 25 million to 50 million people, half in Asia and Africa and half in Europe (a quarter of the population). Its entry into Europe was through Kaffa, a small Italian trading colony on the shore of the Black Sea in Crimea. Kaffa was besieged by an army and during the siege, plague broke out among the soldiers. According to some sources, the soldiers threw the corpses of those who died over the town walls to spread plague among the men defending the town. Whether that caused plague to break out in the town is unknown, but the defenders were afflicted. They managed to get to their boats and flee to Italy, unknowingly carrying the disease with them.

By late 1347, plague was widespread in the Mediterranean region, and in 1348 it spread throughout Italy, France, and England. The Middle East and the Far East were also severely affected. Medieval physicians were at a loss to explain the disease. Some claimed it was due to person-to-person infection, while others said it arose from a poisonous atmosphere . Other explanations put forth by panicked citizens blamed astrological influences, divine punishment, and the Jewish community. Tens of thousands of Jewish citizens were burned in Spain, Germany, Switzerland, and France despite protests by Pope Clement VI, Emperor Charles IV, and medical experts who said that they were innocent. However, the authorities were powerless to stop the spread of plague, and they were not believed. Quarantines of plague victims were ordered, but they were largely ineffective.

The Black Death was the beginning of a number of plague outbreaks that ravaged Europe and Africa in subsequent centuries. In England alone, there were plague outbreaks in 1361, 1369, 1390, 1413, 1434, 1439, and 1464. Additional outbreaks occurred in Scotland in 1401–1403, 1430–1432, and 1455. The epidemics cut England's population of about seven million in half from 1300 to 1380. The last major outbreaks of the Black Death pandemic occurred in London in 1665–1666 and in Marseilles in 1720–1722. Each of these outbreaks resulted in approximately 100,000 deaths.

In a controversial 2001 book, "Biology of Plagues," authors and epidemiologists Susan Scott and Christopher Duncan write they believe the plague of 1347–1351 was not caused by the bubonic plague, but rather by a still unknown disease. They say the quick spread of the disease and the fact that bubonic plague is not transmitted person to person, as the Black Death was, points to another cause. Another possibility, however, is that the ship trade of that time would have allowed for disease-infested rats to move from location to location rapidly and thus, spread the disease quickly through various populations.

The world's third plague pandemic began in 1894 in China and Hong Kong. Called the Modern Pandemic, it quickly spread throughout the world, carried by rats aboard steamships. From 1894 through 1903, plague-infested ships had brought the disease to 77 ports in Asia, Africa, Europe, North America, Australia , and South America. In India alone, plague killed about 13 million people. In the year the pandemic started, scientists discovered the cause of the disease, and established that rats and their fleas were the carriers.

According to most sources, the Modern Pandemic continues to the present time. Epidemics linked to the Modern pandemic were reported in San Francisco, New Orleans, and other coastal cities throughout the world and millions died. The Modern pandemic also established in areas that previously had been plague free, including North America, South America, and southern Africa. With the advent of antibiotics and the understanding of how plague spreads, the Modern pandemic has been contained and the plague no longer claims millions of victims. However, health authorities remain vigilant because the plague has not been eradicated.

At the turn of the twentieth century, plague outbreaks twice hit San Francisco. The first outbreak was from 1900 to 1904, and the second from 1907 to 1909. Several hundred infections were confirmed but health officials believe hundreds of cases went unreported. More recently, an outbreak of bubonic plague occurred in the African nation of Malawi in early 2002, infecting at least 10 people

The decrease in the incidence of plague today is due primarily to improved living standards and health services in many underdeveloped nations. In India, plague epidemics have stopped altogether. The reasons for this are not clear, according to WHO scientists. The Government of India, however, has taken a number of stringent measures to prevent spread of the disease. These include mandatory screening at airports of every airline passenger intending to travel abroad for signs and symptoms of plague, fumigation of aircraft, including both the passenger cabin and the cargo hold. Additionally, all aircraft are inspected for the presence of rats. At all major sea ports, all out-going vessels are being inspected for the presence of rats and insects. Ships are required to have a certificate, issued by the port health officer, showing that they have been deratted, before they can leave port. All these measures are in accordance with the WHO International Health Regulations.

Plague is often mentioned as a potential biological weapon of terrorists. When released into the air, the bacterium can survive for up to an hour. Of the three types of plague (pneumonic, bubonic, and septicemic), pneumonic is they one most likely to be used by terrorists since large stockpiles were developed by the United States and Soviet Union in the 1950s and 1960s. Much of the Soviet supply is now in the hands of several of its former republics, now independent nations. The U.S. government believes several so-called "rogue" nations, such as Iran, Iraq, and North Korea, have biological weapons programs. While several other nations presumably have biological weapons programs, these nations pose a more significant threat to the United States and its allies.

[Ken R. Wells ]

RESOURCES

BOOKS

Kohn, George C., ed. Encyclopedia of Plague and Pestilence: From Ancient Times to the Present. New York: Facts on File, Inc., 2001.

PERIODICALS

Childress, Diana. "Like Black Smoke, the Black Death's Journey." Calliope (March 2001): 4.

Ligomeka, Brian. "Bubonic Plague Breaks Out in Lilongwe." Africa News Service, May 10, 2002.

Mackenzie, Deborah. "All Fall Down: The Black Death Wasn't Caused by Bubonic Plague, and We Need to Find the Real Culprit Before it Strikes Again." New Scientist (November 24, 2001): 35–38.

McCabe, Suzanne. "Dark Death: In 1347, a Terrible Plague Brought Death and Destruction to Europe." Junior Scholastic (February 11, 2002): 18–22.

Saul, Nigel. "Britain 1400." History Today (July 2000): 38.

"Time Trip. (Black Death)" Current Events, a Weekly Reader Publication, January 11, 2002): 2–3.

Truitt, Elly. "The Medical Response to the Black Death." Calliope (March 2001): 14.

ORGANIZATIONS

World Health Organization Regional Office, 525 23rd Street NW, Washington, DC USA 20037 (202) 974-3000, Fax: (202) 974-3663, Email: [email protected], <http://www.who.int>