14th Century to Present
WorldwidePlague is an infectious disease caused by the bacterium Yersinia pestis. Symptoms include fever, weakness and headache. Usually this begins one to seven days after exposure. In the bubonic form there is also swelling of lymph nodes, while in the septicemic form tissues may turn black and die, and in the pneumonic form shortness of breath, cough and chest pain may occur. Transmission of Y. pestis to an uninfected individual is possible by any of the following means. droplet contact – coughing or sneezing on another person direct physical contact – touching an infected person, including sexual contact indirect contact – usually by touching soil contamination or a contaminated surface airborne transmission – if the microorganism can remain in the air for long periods fecal-oral transmission – usually from contaminated food or water sources vector borne transmission – carried by insects or other animals.
Antonine Plague, also known as the plague of Galen, the Greek physician living in the Roman Empire who described it. It is suspected to have been smallpox or measles. The total deaths have been estimated at five million and the disease killed as much as one-third of the population in some areas and devastated the Roman army.
The Plague of Justinian, considered the first recorded pandemic, breaks out and develops as an extended epidemic in the Mediterranean basin. According to some, frequent outbreaks over the next two hundred years would eventually kill an estimated 25 million people. This number has recently been disputed.
The second plague pandemic breaks out in China. Widely known as the "Black Death" or the Great Plague, it is regarded as one of the most devastating pandemics in human history, resulting in the deaths of an estimated 75 to 200 million people in Eurasia.
In 1347, the Genoese possession of Caffa, a great trade emporium on the Crimean peninsula, came under siege by an army of Mongol warriors of the Golden Horde under the command of Janibeg. After a protracted siege during which the Mongol army was reportedly withering from the disease, they decided to use the infected corpses as a biological weapon. The corpses were catapulted over the city walls, infecting the inhabitants. This event might have led to the transfer of the plague (Black Death) via their ships into the south of Europe, possibly explaining its rapid spread.
The Black Death arrives at Melcombe Regis in the south of England. Over the next year, the plague spreads into Wales, Ireland and Northern England. By 1350, the plague reaches Scotland. The estimated death toll for the British Isles and Ireland is calculated at 3.2 million.
Black Death Jewish persecutions. A rumor rises claiming that Jews are responsible for the plague as an attempt to kill Christians and dominate the world. Supported by a widely distributed report of the trial of Jews who supposedly had poisoned wells in Switzerland, the rumor spreads quickly. As a result, a wave of pogroms against Jews breaks out. Christians start to attack Jews in their communities, burning their homes, and murder them with clubs and axes. In the Strasbourg massacre, it is estimated that people locked up and burned 900 Jews alive. Finally, Pope Clement VI issues a religious order to stop the violence against the Jews, claiming that the plague is “the result of an angry God striking at the Christian people for their sins.”
The Republic of Ragusa establishes a landing station for vessels far from the city and harbour in which travellers suspected to have the plague must spend thirty days, to see whether they became ill and died or whether they remained healthy and could leave.
After finding thirty days isolation to be too short, Venice dictates that travelers from the Levant in the eastern Mediterranean be isolated in a hospital for forty days, the quarantena or quaranta giorni, from which the term quarantine is derived.
A new outbreak of bubonic plague occurs, in the Canary Islands, mainly affecting the city of San Cristóbal de La Laguna on the island of Tenerife. Between 5,000 and 9,000 people die, a considerable number considering that the population of the island at the time was less than 20,000 inhabitants.
The Italian plague of 1629–1631 develops as a series of outbreaks of bubonic plague. About 280,000 people are estimated to be killed in Lombardy and other territories of Northern Italy. The Italian plague is estimated to have claimed between 35 and 69 percent of the local population.
Russian bacteriologist Waldemar Haffkine successfully protects rabbits against an inoculation of virulent plague microbes, by treating them previously with a subcutaneous injection of a culture of the microbes in broth. The first vaccine for bubonic plague is developed. The rabbits treated in this way become immune to plague. In the next year, Haffkine causes himself to be inoculated with a similar preparation, thus proving in his own person the harmlessness of the fluid. This is considered the first vaccine against bubonic plague.
During World War II, the Japanese Army developed weaponised plague, based on the breeding and release of large numbers of fleas. During the Japanese occupation of Manchuria, Unit 731 deliberately infected Chinese, Korean and Manchurian civilians and prisoners of war with the plague bacterium. These subjects, termed "maruta" or "logs", were then studied by dissection, others by vivisection while still conscious. Members of the unit such as Shiro Ishii were exonerated from the Tokyo tribunal by Douglas MacArthur but 12 of them were prosecuted in the Khabarovsk War Crime Trials in 1949 during which some admitted having spread bubonic plague within a 36-kilometre (22 mi) radius around the city of Changde.
After World War II, both the United States and the Soviet Union developed means of weaponising pneumonic plague. Experiments included various delivery methods, vacuum drying, sizing the bacterium, developing strains resistant to antibiotics, combining the bacterium with other diseases (such as diphtheria), and genetic engineering. Scientists who worked in USSR bio-weapons programs have stated that the Soviet effort was formidable and that large stocks of weaponised plague bacteria were produced. Information on many of the Soviet projects is largely unavailable. Aerosolized pneumonic plague remains the most significant threat. The plague can be easily treated with antibiotics. Some countries, such as the United States, have large supplies on hand if such an attack should occur, thus making the threat less severe.
Researchers at Duke University School of Medicine and Duke-NUS Medical School Singapore find the Yersinia pestis bacteria to hitchhike on immune cells in the lymph nodes and eventually ride into the lungs and the blood stream, thus spreading bubonic plague effectively to others.
Globally about 600 cases are reported a year. In 2017 the countries with the most cases include the Democratic Republic of the Congo, Madagascar and Peru. It has historically occurred in large outbreaks, with the best known being the Black Death in the 14th century which resulted in greater than 50 million dead.