Like?

Plague: Symptoms, Diagnosis & Treatment

Start Your Free Trial To Continue Watching
As a member, you'll also get unlimited access to over 8,500 lessons in math, English, science, history, and more. Plus, get practice tests, quizzes, and personalized coaching to help you succeed.
Free 5-day trial
It only takes a minute. You can cancel at any time.
Already registered? Login here for access.
Start your free trial to take this quiz
As a premium member, you can take this quiz and also access over 8,500 fun and engaging lessons in math, English, science, history, and more. Get access today with a FREE trial!
Free 5-day trial
It only takes a minute to get started. You can cancel at any time.
Already registered? Login here for access.
  1. 1:58 Plague and Symptoms
  2. 5:03 Diagnosis
  3. 5:55 Treatment
  4. 6:32 Lesson Summary
Show Timeline
Taught by

Angela Hartsock

Angela has taught college Microbiology and has a doctoral degree in Microbiology.

In this lesson, we will examine plague, more widely known as Black Death, including the three major types of plague, the most common symptoms, diagnosis, and treatment.

Two Days Until Death

The life of a high school senior can be hectic, stressful, and exciting. There are so many choices and changes on the horizon during the transition to adulthood. Every kid deserves a little break now and then to blow off some steam. That was what B.T. (the name has been changed to protect confidentiality) thought with his final exams and wrestling championships fast approaching. What better way to relax than a nice nature hike through the beautiful scenery of central Arizona? He might even get to feed the prairie dogs again.

Two days after his hike, B.T. suffered a groin injury while wrestling. His leg was swollen and very painful, and he was starting to develop a fever. His doctor advised at-home rest and observation. The next morning, B.T. was found dead on his bathroom floor. The doctors racked their brains trying to find a cause. On a whim, the public health department decided to retrace B.T.'s hiking trail. There, they found a colony of prairie dogs. But the rodents were not acting normal. Many were sick. Others had already died. Could the disease affecting the prairie dog colony be related to B.T.'s death?

The health department managed to trap a sick prairie dog for testing. It turns out the prairie dogs were dying of plague - you know, Black Death, Middle Ages plague! Who gets plague these days - and in the United States, no less? A quick test confirmed that B.T. also died of plague. A healthy individual in a relatively protected, developed country died of one of the most notorious diseases in human history. And it only took 2 days. So let's look a little closer at the plague. Maybe if B.T. had been more informed, his death could have been prevented.

Plague and its Symptoms

Plague is a deadly, infectious disease caused by the bacterium Yersinia pestis. There are three main types of plague - bubonic, pneumonic and septicemic - each with its own unique characteristics. Let's take a quick look at all three, beginning with the most infamous: bubonic plague.

Bubonic plague is the classic form of plague transmitted through the bite of an infected flea. When an infected flea bites a human, it injects Yersinia cells into the human host. It can take as few as 3 cells to start an active, life-threatening infection. Once bitten, the bacteria travel to the lymph node closest to the bite site, where they are filtered out of the lymph fluid. The bacteria encapsulate, making a compartment within the lymph node where they can grow and divide. This causes inflammation and cell death of the node. The lymph node rapidly begins to swell and becomes painful. The swelling of the node is called a bubo - hence the name 'bubonic plague.' In addition, bubonic plague victims suffer from a sudden onset of fever, headache, chills, and muscle weakness. Bubonic plague has a mortality rate of around 15%, even with treatment.

Pneumonic plague is a highly contagious form of plague usually transmitted person-to-person through inhaled aerosolized respiratory droplets. Yersinia cells inhaled will encapsulate and cause inflammation in the lungs, resulting in the rapid onset of pneumonia. The patient will have shortness of breath, chest pain, coughing, and bloody mucous. In addition, the normal immune response to a bacterial infection will cause fever, headache, and general weakness. This is the most serious form of plague and the only form that can be passed from person to person. But that is not the only way to develop pneumonic plague. If a case of bubonic or septicemic plague is allowed to progress without treatment, Yersinia cells will eventually invade the lungs, leading to pneumonic plague. Without treatment, nearly 100% of patients will die within 6 days from respiratory failure and shock. Even with treatment, prognosis is grave. As a result of the grave prognosis and ability to aerosolize, plague is a very serious bioterrorism threat.

Septicemic plague is a form of plague in which the bacteria have invaded the host's blood stream. This form of plague can develop directly from a flea bite, through bacterial contamination of broken skin, or as a later stage of both bubonic and pneumonic plague. Symptoms include fever, chills, extreme weakness, abdominal pain, and bleeding under the skin or in the organs. Eventually, shock and death result from the body-wide infection. It is septicemic plague that started the name 'Black Death.' As bleeding under the skin increases, large purple-to-black patches of blood and dying tissue develop. By the time these patches develop, about 50% of patients undergoing treatment will die. In untreated patients, the disease is 100% fatal.

Unlock Content Over 8,500 lessons in all major subjects

Get FREE access for 5 days,
just create an account.

Start a FREE trial

No obligation, cancel anytime.

Want to learn more?

Select a subject to preview related courses:

People are saying…

"This just saved me about $2,000 and 1 year of my life." — Student

"I learned in 20 minutes what it took 3 months to learn in class." — Student

See more testimonials

Did you like this?
Yes No

Thanks for your feedback!

What didn't you like?

What didn't you like?

bmitNegativeComments" type="button" value=""/>

Next Video
Create your Account

Sign up now for your account. Get unlimited access to 8,500 lessons in math, English, science, history, and more.

Meet Our Instructors

Meet all 53 of our instructors

Copyright
((document.getElementsByTagName('head') || [null])[0] || do