Plague: Symptoms, Diagnosis & Treatment

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Toxic Shock Syndrome: Symptoms & Causes

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
Your next lesson will play in 10 seconds
  • 1:58 Plague and Symptoms
  • 5:03 Diagnosis
  • 5:55 Treatment
  • 6:32 Lesson Summary
Save Save Save

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Log in or Sign up

Speed Speed Audio mode
Lesson Transcript
Instructor: 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.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account