A Plague Analysis



The Plague was a devastating disease that spread all over Europe in the 14th century and caused widespread death and suffering. It is important to analyze the Plague in order to better understand its causes, effects, and the measures that were taken to mitigate its spread.

In this paper, we will discuss:

  • The history of the Plague.
  • The impact it had on Europe.
  • The theories that have been proposed to explain it.
  • An overview of the various interventions that were taken in order to contain the spread of the Plague.

Definition of Plague

Plague is a highly virulent, infectious disease primarily caused by Yersinia pestis, a bacterium typically transmitted to humans via flea bite. It is believed that up to 200 million people have died from Plagues throughout history, with notable outbreaks occurring in Europe during the middle ages. Symptoms typically include fever, chills, headaches and swollen lymph nodes. Without proper and timely treatment with antibiotics, plague can rapidly progress to result in serious complications such as sepsis and shock.

Plague infections can be categorized into three common forms – bubonic plague, septicemic plague, and pneumonic plague. The bubonic form is referred to as the original “Black Death” because of its potential to cause extreme mortality via massive internal bleeding if left untreated. Septicemic plague occurs when Yersinia pestis rapidly multiplies in the bloodstream of an infected person instead of in the lymph node; it has been documented to occur without iatrogenic intervention in patients who have received inadequate (or no) antibiotics for treatment of bubonic plaque infections. Finally the most virulent form is pneumonic plaque which primarily affects the lungs; spread between two humans has been documented via airborne transmission though this is rare even during major “plague pandemics” or outbreaks due to medical interventions available for treatment and widespread protective measures taken by health practitioners who are aware or anticipate a possible outbreak.

History of Plague

Plague has been a major source of human suffering throughout history. Its sudden and devastating occurrence in several regions of the world had far-reaching consequences and tragic death tolls.

The first recorded plague, known as the “Plague of Justinian” occurred in 541-542 CE, claiming an estimated 10 million lives, or one quarter of the entire population of Constantinople. It is believed to have been plague bubonicus, a subspecies spread by rat fleas that are carried by black rats living in populated areas. This strain likely originated in Central Asia and was spread along trading routes via caravans, ships and humans migrateing to populated areas.

The next major epidemic was the “Black Death” that occurred between 1347 and 1351 CE with casualties reaching an astonishing 200 million people across Eurasia. It is believed to have originated from central Asia once again and spread through Europe quickly due to large tradeships traveling along seaside ports on the Mediterranean Sea. The Black Death peaked during this time period with up to 100 people dying daily in many cities like Venice or Paris and was responsible for wiping out one third of Europe’s population at its peak.

Centuries later, outbreaks continued to devastate populations across the globe following similar patterns as before. The greatest epidemic after the Black Death happened between 1894 – 1897 resulting in 12 million deaths worldwide including thousands in Southern India alone, followed by another outbreak occurring between 1901 – 1909 resulting 8 million more deaths with India being especially hard hit once again. Through understanding its history it is clear that plague can cause severe illnesses outbreaks anytime if circumstances are favorable for its survival.

Types of Plague

The plague is an infectious disease caused by Yersinia pestis bacteria. It has a long and fascinating history, with three distinct types: bubonic, septicemic, and pneumonic plague. Each type is caused by a different part of the Yersinia pestis bacteria.

In this article, we will walk through the basics of these three types, the symptoms they cause, how they are transmitted, and how they are treated:

  • Bubonic plague
  • Septicemic plague
  • Pneumonic plague

Bubonic Plague

Bubonic plague is the most common, and luckily the least deadly, type of plague. It is caused by the bacterium Yersinia pestis and primarily affects rodents, such as rats, and their fleas. Humans can become infected by being bitten by an infected flea or through direct contact with an animal that carries the bacteria.

When bubonic plague is not treated quickly with antibiotics like tetracycline or gentamicin, it can cause severe sepsis and spread to other parts of the body such as the lungs (pneumonic) or blood (septicemic). Bubonic plague symptoms begin 2 to 5 days after infection and include:

  • Fever typically with chills
  • Headache
  • Muscle aches
  • Fatigue
  • Swollen lymph nodes
  • Sore throat
  • Nausea

Without prompt diagnosis and treatment bubonic plague cases can be fatal but mortality rates are lower today than it was during its pandemics in Europe during the Middle Ages because of modern medicine’s increased understanding of Y. pestis bacteria.

Pneumonic Plague

Pneumonic plague is an extremely contagious and serious form of the plague. This strain of Yersinia pestis, the bacteria that causes bubonic plague, is transmitted directly from person to person through coughs or sneezes from an infected person into the nose or mouth of someone nearby. It can also be contracted by coming in contact with objects like clothing or linens that have been contaminated with droplets from a sneeze or cough of an infected individual. The most common way to contract pneumonic plague is by contracting bubonic plague and then not receiving appropriate medical treatment so that it progresses to the more serious form of the illness.

Symptoms usually start within less than 24 hours after exposure and may include:

  • Fever
  • Chills
  • Chest pain
  • Weakness
  • Headache
  • Coughing (sometimes with blood-tinged sputum)

If left untreated, pneumonic plague can cause death in 1–6 days. Antibiotics are effective against pneumonic plague when administered early after infection; however, if untreated it will progress rapidly and may cause death within a matter of hours.

Septicemic Plague

Septicemic plague is the rarest form of plague and occurs when the bacteria get directly into circulation. It also may be caused by direct contact with infected materials or from flea bites in rats, rabbits, and other small mammals. Septicemic plague can occur as a result of pneumonic or bubonic plague that is left untreated.

Signs and symptoms vary from mild to severe and include fever, weakness, extreme exhaustion, abdominal pain, shock and bleeding into the skin and other organs yet who are not treated will almost certainly die from the infection. People with this form of plague require hospitalization to receive antimicrobial drugs intravenously; without prompt treatment death may occur within hours of onset.

Other complications include:

  • Multiple organ failure
  • Coagulopathy (disorders affecting blood clotting)
  • Meningitis (an infection of the protective membranes that cover the brain)
  • Seizures or coma

Causes of Plague

The plague is a serious and deadly disease. In order to understand the plague, it is important to understand the causes of it. The plague is caused by a bacteria called Yersinia pestis, which is primarily found in fleas, though it can also be found in other animals. This bacteria is then transmitted to humans through contact with an infected animal, such as a rat.

This article will take a look at the various causes of plague, from fleas to environmental factors:

  • Fleas – The primary cause of plague is fleas, which carry the Yersinia pestis bacteria.
  • Animals – The Yersinia pestis bacteria can also be found in other animals, such as rats, and can be transmitted to humans through contact with an infected animal.
  • Environmental Factors – Environmental factors such as overcrowding, poor sanitation, and lack of access to medical care can increase the risk of plague.

Rodents and Fleas

Rodents and fleas are some of the most common carriers of the plague. All species of rodents may become infected with Yersinia pestis, the bacterium that causes plague, either from contact with an infected animal or through inhalation. Fleas, in turn, can become infected when biting an infected animal.

The most commonly implicated rodent hosts of Yersinia pestis are black rats and Norway rats, although other murid rodents such as ground squirrels and prairie dogs may also play a role in spreading plague. The flea vector most often associated with transmission to humans is Xenopsylla cheopis (the Oriental rat flea), although other flea species (e.g., Nosopsyllus fasciatus) have been implicated in epizootics involving various wild animals and also appear to cause human cases of plague.

Plague transmission is generally seen when these rodent populations increase for extended periods, allowing for increased contact between people, rodents and their fleas. When seeking food or mates, potentially infected rodents spread the bacteria to new areas across highways or over long distances by means of human transportation networks or jumping aboard ships or airplanes traveling anywhere across continents. Outbreaks can then occur in cities that experience overcrowding, poor sanitation and inadequate health care services.

Person-to-Person Transmission

Person-to-person (or human-to-human) transmission of plague is spread by the bites of infected fleas, contact with infected animals, or through the air when a person breathes in respiratory droplets of an infected person coughing.

Infected fleas can pass the bacteria to humans when they bite. Plague can spread quickly among rodents and other small mammals such as prairie dogs and sheep. For example, a flea that initially fed on an infected rodent is likely to feed on another animal or human when it leaves its host, thus passing on the bacteria it contains.

Person-to-person transmission can also occur through contact with bodily fluids from an infected individual if they are not adequately isolated. In areas where plague is common, strict isolation protocols must be abided by for those diagnosed with plague in order to prevent the spread of infection. Additionally, health workers should wear protective clothing and respirators when caring for anyone who may have been exposed to the disease; this helps reduce their risk of becoming ill from direct contact or airborne exposure.

Finally, laboratory personnel should take proper safety precautions while performing any tests that involve the use of live bacteria samples such as those used in PCR (polymerase chain reaction) tests. Appropriate safety measures help protect laboratory workers from any potential exposure to Yersinia pestis during these tests. These steps include:

  • Wearing personal protective equipment such as gloves and masks.
  • Decontaminating equipment after each test is completed.
  • Disposing of potentially contaminated samples correctly according to local regulations.

Symptoms of Plague

Plague is a deadly disease that has been around since ancient times. It is caused by a bacteria called Yersinia pestis and is highly contagious. When an individual is infected, they will typically experience a range of symptoms.

In this article, we will discuss the key symptoms of plague and how to properly identify them:

Bubonic Plague

Bubonic plague is an infection caused by the Yersinia pestis bacterium. It is quite rare and most commonly found in rodents like rats and mice, but it can also infect humans via flea bites or direct contact with animals or humans infected with the bacteria. Also known as the Black Death, it was responsible for a massive outbreak that killed millions of people in Europe during the Middle Ages.

Symptoms of bubonic plague include:

  • Painful, swollen lymph nodes (called buboes) near areas such as the groin and armpits
  • Unexplained fever and chills
  • Headaches
  • General feeling of discomfort (malaise)
  • Extreme tiredness (fatigue)
  • Loss of appetite
  • Nausea and vomiting

Left untreated, bubonic plague can cause organ failure, shock, and even death within a few days. It is crucial to seek medical attention right away if you suspect an infection so that appropriate antibiotic treatment can be started to prevent serious illness or death.

Pneumonic Plague

Pneumonic Plague is the most severe form of plague and is extremely contagious. Symptoms can set in between one and seven days after exposure, which is much faster than the two to seven days of incubation for bubonic plague.

This form of plague is spread through the air by droplets of saliva or nasal discharge from an infected person or animal. It can occur in both humans and other mammals, and is caused by a strain of the Yersinia pestis bacteria.

Common symptoms include:

  • High fever
  • Productive coughing (with blood-tinged sputum or phlegm)
  • Chest pain due to breathing difficulty
  • Rapid heart rate
  • Breathing trouble

Other possible symptoms include headache, nausea, vomiting, joint pain, fatigue and confusion. Without prompt treatment, the disease can progress rapidly to cause respiratory failure resulting in death within 24 hours after symptoms start appearing.

Septicemic Plague

Septicemic plague, also known as Bubonic plague, is caused by a bacterial infection and is the most severe type of plague. It is a highly contagious illness spread through contact with infectious materials or infected animals, such as rodents and their fleas. Symptoms can develop suddenly and quickly become life-threatening without prompt treatment.

Common signs of septicemic plague include:

  • High fever, chills, abdominal pain that may come and go along with vomiting or diarrhea, weak pulse, extreme exhaustion due to septic shock (failing body organs),
  • Dark blotches on the skin (particularly feet or legs) due to bleeding under the skin caused by decreased circulation and oxygenation of red blood cells,
  • Confusion or delirium due to internal toxins from the bacterial infection accumulating in the blood stream,
  • Some patients also experience breathing difficulties due to pulmonary edema from sepsis,
  • In some cases, buboes (large swollen lymph nodes) will form in areas like the neck, armpit or groin but this is less common during septicemic plague than other forms of plague.

If left untreated; seizures, coma, organ failure and death can occur.

Treatment of Plague

Though plague is considered a rare disease in modern times, it has been around for centuries. As a result, there are many treatments and medicines that have been developed over the years to combat this deadly disease.

In this article, we will look at the different treatments available for plague, including some that are newly developed, as well as traditional treatments that may still be in use:

Antibiotic Therapy

Antibiotic therapy has increased greatly in effectiveness over the course of time. During the Middle Ages, physicians were limited to herbal remedies, incantations, prayer, and leeches for treating patients. In more recent times, penicillin and tetracycline have been used to treat plague infections successfully.

The earliest antibiotics used to treat plague consisted mainly of sulfonamides and penicillin. Sulfonamides were the first true antimicrobial agent but their usefulness was limited due to fast bacterial development of resistance towards it. Penicillin is still the preferred antibiotic against plague bacteria but its application can be difficult due to renal or gastrointestinal side effects and a potential allergic reaction in some individuals.

Tetracyclines are another class of antibiotics which are widely employed to control pneumonic plague as well as bubonic cases. These antibiotics also possess an advantage in treating relapsed infections with increasing concentrations that can kill aerobic gram-negative bacilli such as Yersinia pestis and other select microorganisms. Tetracyclines can provide adequate suppression during the recovery period from quinolones such as ciprofloxacin or levofloxacin, although not generally recommended for initial treatment because of their delayed effect profile compared to penicillins or sulfonamides.

Macrolide antibiotics have also been tested for treatment of primary pneumonic plague but have only been shown to be effective when given after initiation of penicillin therapy as an adjunct regime; however they do provide additional protection against gram-positive bacteria, notably Streptococcus pneumoniae and Legionella spp., which is exclusive benefits that these agents may have over other antibacterial agents used alone against plague infections.

Prevention and Control

Prevention and control of plague is based on controlling contact with rodent or flea populations, preventing their entrance or access to dwellings, and eliminating all possible sources of food. Dead rodents that are suspected to have died due to plague should be burned or deeply buried.

Public health measures such as education and vaccination have been used to great effect in the management of outbreaks. Vaccines are available for people at risk of exposure such as laboratory personnel, veterinarians, pest control workers and those living in areas where plague-carrying rats and fleas are found. Rapid detection and treatment of cases is essential for breaking the transmission chain since successful treatment reduces infectivity by 90%.

In order to prevent transmission from person-to-person it is essential to:

  • Identify possible exposures as soon as possible after symptoms develop; this involves epidemiological investigation into recent contacts, particularly identifying any pneumonic cases
  • Person-to-person spread requires urgent initiation of recommended antimicrobial therapy.

Control strategies also include using protective equipment when coming into contact with fluids from confirmed or suspected plague cases and rigorous infection prevention practices in hospitals including the use of disposable protective equipment whenever handling carcasses from infected animals.


After examining the devastating impact of the plague, one can see its far-reaching consequences. The pandemic led to enormous destruction, both physical and psychological, with surviving individuals becoming heavily scarred by the tragic events. From rural communities that experienced high mortality rates to wealthy cities broken by severe depopulation, no place was immune to such destruction. The drastic financial and political situations of those affected severely disrupted social organizations and systems, leaving lasting repercussions still seen today.

The essence of this examination is simply this: the Plague had a massive influence on pre-modern times, afflicting its victims in an unprecedented manner. Furthermore, it left deep scars in Europe’s economic infrastructure, medical knowledge and religious practices which reverberated throughout various aspects of life in subsequent generations. By understanding this history we will be better equipped to prevent similar instances of catastrophic losses from occurring again in our future as humanity continues its journey into the unknown.