The impact of the bubonic plague epidemics of the past still echo across the centuries, reminding us of the devastation that disease can inflict on communities.
The Roman physician Galen coined the term ‘plague’ to describe any quickly spreading fatal disease. Epidemics of all kinds have been described as plagues, but the bubonic plague is a very specific disease that first spread around the world in the 1300s.
Bubonic plague is a highly infectious disease spread by fleas that bite their hosts (usually rats and humans) and introduce the bacteria that cause the disease into their hosts’s bodies.
Infectious diseases like the bubonic plague that spread rapidly among a community or region within a short period of time are called epidemics.
The Black Death is the name given to the first wave of the plague that swept across Europe in the 1300s.
It is called a pandemic because it spread across many countries and affected many populations.
Plague pandemics hit the world in three waves from the 1300s to the 1900s and killed millions of people. The first wave, called the Black Death in Europe, was from 1347 to 1351. The second wave in the 1500s saw the emergence of a new virulent strain of the disease. The last pandemic at the end of the 1800s spread across Asia and at last gave scientific medicine the opportunity to identify the cause of the disease and its means of transmission.
The Black Death
The Black Death was probably the earliest recorded pandemic. It took around four years to make its way along the Silk Road from the Steppes of Central Asia, via Crimea, to the Western most parts of Europe, the Middle East and North Africa.
In Europe alone it wiped out an estimated one to two thirds of the population. Many communities encountered the disease for the first time and had no idea how to respond.
It’s possible that outbreaks of other diseases such as smallpox and leprosy were also attributed to plague at the time. But the pattern of symptoms described were largely consistent with one disease, and the collective experience was of that disease.
Common symptoms were the appearance of painful bubos—hence the name bubonic plague—in the groin, neck and armpits, which later secreted pus and blood. These were followed by acute fever and vomiting blood. Victims usually died between two and seven days after being infected. The death rate was 60–90 per cent.
The medical authorities of the day had little to offer. 'Leave quickly, go far and come back slowly' was the general advice about what to do if an epidemic came to your town.
Controlling the spread of plague
The Black Death arose at a time of emerging empires, greater exploration and new discoveries. Armies, colonisers and traders all imported and exported the disease in ships and overland.
When the plague first came to Europe on Italian trading ships, arriving from Crimea, the Italian authorities instituted some of the first official public health measures. Many local and civic authorities became involved in public health for the first time and many of the measures they instituted were used for centuries afterwards to control the spread of any infectious disease outbreak.
Public Health measures
Many of the public health measures that we would recognise today first emerged during the Black Death. These included:
Medical inspections. A plague doctor would come to inspect suspected cases of plague and isolate the infected and their families in their homes.
Isolation of people who were sick in plague hospitals. Hospitals were built throughout Europe and remained as fever hospitals for infectious patients up until the 1900s.
Restricting ships to port. In 1347 the Venetian authorities isolated ships in port for 30 days to ensure they were not infected. The period was extended to 40 days, and the word 'quarantine' comes from the italian word for 40.
Control of the movement of people and goods.
Epidemic waves across the centuries
The first pandemic wave of plague began to die out in Europe after four years, but pockets of the disease remained, and small isolated outbreaks continued until the rise of the second pandemic in the late 1500s.
The second pandemic saw a more virulent form of the disease, which hit France particularly badly, killing two and a half million between 1600 and 1670. Epidemics also hit Italy, Holland and England. The last major outbreak in London was 1665–1666, just before the Great Fire of London.
Outbreaks in Western Europe declined from the mid-1600s. The last great epidemic in France was 1720 and Russia in the 1770s. Why it declined is unclear.
A bacterial infection is confirmed
Outbreaks of plague continued in Asia throughout the 1800s. The third pandemic wave began in Southern China in 1865, spreading south and west. Between 1894 and 1929 there were over 24,000 cases in Hong Kong. From Hong Kong it entered the ports of India, where at least 12 million people died over 20 years.
By the end of the 1800s, developments in bacteriology and infection control meant that medical researchers were able to observe and investigate the disease in detail for the first time.
A team of European scientists was sent to colonial Hong Kong in the 1890s to study the epidemic. French-Swiss bacteriologist Alexandre Yersin isolated the bacterium that caused the disease in 1897, and it was named Yersinia pestis after him.
In 1898 Paul Louis Somond established the mechanism for transmission was via fleas, which transferred bacteria from infected hosts to the non-infected through their bites. The fleas were transported around the world overland and on ships by black rats.
Known as house rats or ship rats, black rats liked to live in close proximity to humans. When the rats died the fleas moved onto human hosts. The fleas also infested clothing and could be carried to other locations in that way.
An international vaccine for a pandemic disease
From Hong Kong the epidemic spread to the major Indian ports. When the plague broke out in Bombay in colonial India in 1893, in the Nowroji Hill district, a Goan doctor called Acacio Viegas was the first to identify the disease as bubonic plague. His vociferous campaign to clean up the slums and kill rats prompted the colonial authorities to call in scientific experts, including Waldemar Haffkine (1860–1930).
Haffkine had worked at the Pasteur Insitute in Paris and was developing a cholera vaccine at the time. He established a laboratory in Bombay in 1893 where he worked on a plague vaccine.
The immunology of bubonic plague proved challenging but in October 1896 he produced a vaccine ready for human testing. Haffkine tested it on himself first, then on prison volunteers.
There were some side effects from the vaccine, and incomplete protection but the risk of contracting bubonic plague was reduced by 50%. By 1900, over four million people had been inoculated.
Controlling plague in colonial India
The experience of plague in 1800s Bombay shows just how complex it can be to control an epidemic in large populations.
As with other plague epidemics, the outbreak in India had a major social impact. Many people left the city, causing a significant drop in the population. Many in the infected area were mill workers and the epidemic effectively brought the textile industry to a halt.
The colonial authorities instituted an aggressive programme of anti-plague measures, including house searches for victims, enforced evacuation of residents in infected areas, detention camps for travellers and the exclusion of traditional medicine practitioners from infected areas.
The restrictions were imposed by the Special Plague Committee and enforced by the colonial army. Such tactics caused widespread protests and alarm among the various communities, culminating in the murder of the British chairman of the Special Plague Committee in the city of Pune.
But as with earlier outbreaks, some of the measures laid the foundations for public health in modern India. After the outbreak, the authorities in Bombay set up the Bombay City Improvement Trust to try to create a healthier city. Wider roads were planned to channel fresh sea air into the more crowded areas, as a sanitary measure.
And the Haffkine Institute for infectious disease continues its biomedical research in modern Mumbai (formerly Bombay).
By the 1930s plague epidemics were a thing of the past. A few small pockets of infection remain around the world, particularly in central Asia where the disease is endemic.
With modern antibiotics the mortality rate has fallen from over 60% to 11%. But drug resistant forms of the bacteria were identified on the island of Madagascar in 1995. In 2017 the deadliest outbreak in modern times killed 170 people and infected thousands on the island.
Using techniques such as genome mapping, scientists have been able to identify the exact strains of bubonic plague that they encounter and their origins, making it easier to track the spread of epidemics. Genetic evidence of the Yersinia pestis bacterium in several plague burial grounds from 1348–1590, has also confirmed that the Black Death was, in most cases, bubonic plague.
The plague epidemics of the past are a reminder of the social as well as medical impact of epidemics. They led to important developments in infectious disease control—many of which we still use. But the continued presence of bubonic plague is a reminder that epidemics are not necessarily a thing of the past.
Suggestions for further research
- Bollet, AJ; 'Plagues and Poxes: the impact of human history on epidemic disease. New York: Demos, 2004.
- Bourdelais, P; 'Epidemics Laid Low: a history of what happened in rich countries'; Baltimore: Johns Hopkins University Press, 2006.
- Hays, JN; 'Epidemics and Pandemics: their impacts on human history'; Oxford: ABC-CLIO, 2006.
- Oldstone, MBA; Viruses, Plagues and History'; Oxford University Press, 1998.
- Porter, Roy; The Greatest Benefit to Mankind: a medical history of humanity'; London: Harper Collins, 1999.
- Watts, S; 'Disease and Medicine in World History'; London: Routledge, 2003.