This is the eighth of 16 student posts, guest-authored by Michelle Formanek.
For many of us in the scientific world, particularly budding infectious disease epidemiologists like myself, the Plague (or, more dramatically, the “Black Death”) is a prime example of the rapid and devastating spread of an infectious disease. So devastating, in fact, that it wiped out nearly one-third of the population in Europe in the mid-1300’s. That’s roughly equal to 25 million people. It then persisted and has caused various outbreaks throughout history, most notably the Great Plague of London in which 1 in 5 residents died.
So why should be care about the Plague today? Isn’t that old news?
While I will go into more detail about the history of the plague a little later, I first want to mention what prompted me to write about what many people consider to be a no-longer-relevant disease. In order to gauge modern perceptions of the plague, I took a very unofficial survey of friends and family from various backgrounds about what they knew about the Plague. While the knowledge base ranged quite a bit, most were very surprised to hear that we still have cases of the Plague here in the United States.
Yes, you heard me right. The Plague still exists in the United States.
Of course, due to increased knowledge and antibiotic therapy, we no longer see the sweeping epidemic that caused so much turmoil throughout history. Nevertheless, an Oregon man is currently suffering from a rare case of the “Black Death.”
According to reports, a stray cat bit the unidentified man while he was trying to pull a mouse away from the cat. (I won’t even begin to speculate as to why this man was attempting to steal a mouse away from what was likely a very hungry stray cat, but that’s another story.) Several days later the man began to feel ill and presented to the hospital with symptoms typical of the Plague. These included fever, swollen lymph nodes and stomach pain. It has since progressed to bleeding mouth, nose and anus, and dying tissue. Although the CDC has yet to confirm the diagnosis, all signs point to the Plague.
Only 10-15 people report becoming ill with the disease each year in the United States; this man is the fifth person in Oregon since 1995.
The Plague is caused by the bacterium Yersinia pestis., a rod-shaped bacillus that can live in various species of animals including rats, mice, squirrels, cats, prairie dogs, camels, and rabbits, among others. Yersinia pestis can then be transferred to humans through direct contact with infected animals, bites from fleas that have previously fed on infected animals (this is most common), or human-to-human through the air. Historically, the high population of small rodents and their flea friends in urban areas were attributed to the rapid spread of the disease.
While the Bubonic plague may be the most well known form of the disease, there are actually three different types of the Plague. The Bubonic plague is the most common form and is characterized by buboes - painful, swollen lymph nodes – in the groin, armpit or neck. Septicemic plague occurs when the bacteria begins to spread in the bloodstream. Lastly, the most infectious form of the disease is Pneumonic plague. This advanced stage strikes when the bacteria can be passed from person to person through airborne droplets coughed up from the lungs. Bubonic plague is fatal roughly half the time, while Septicemic and Pneumonic are almost uniformly fatal without antibiotic treatment.
The man in Oregon was first believed to be suffering from Bubonic plague, but is now beginning to show signs of Septicemic plague, meaning it has entered his bloodstream and is able to reach all different parts of the body. Luckily, antibiotics are effective in the treatment of the Plague if given early enough. Without antibiotics, 1 in 7 people infected end up dying.
So you may be asking yourself, as I did, where a deadly disease like this came from in the first place. The puzzling start of the epidemic went something like this:
“The Black Death arrived in Europe by sea in October 1347 when 12 Genoese trading ships docked at the Sicilian port of Messina after a long journey through the Black Sea. The people who gathered on the docks to greet the ships were met with a horrifying surprise: Most of the sailors aboard the ships were dead, and those who were still alive were gravely ill. They were overcome with fever, unable to keep food down and delirious from pain. Strangest of all, they were covered in mysterious black boils that oozed blood and pus and gave their illness its name: the “Black Death.” The Sicilian authorities hastily ordered the fleet of “death ships” out of the harbor, but it was too late: Over the next five years, the mysterious Black Death would kill more than 25 million people in Europe–almost one-third of the continent’s population.”
Unfortunately, the cause of the disease was not discovered until 1894, long after it swept through Europe with alarmingly high death rates. People had their ideas about what was causing the Black Death, but no one could actually figure it out. Some believed it was the spirit escaping the eyes of a sick man and infecting the nearest healthy person, others believed it was God’s way of punishing those who had sinned. Citizens were so panicked that they went to extreme lengths to avoid contracting the disease, even so far as to completely abandon loved ones who got sick. More details here.
As mentioned before, antibiotics can be extremely effective in fighting this bacteria. As of right now, the Oregon man is still fighting for this life, but thanks to modern medicine, his chances of living are fairly high. The man likely contracted the disease from the cat; however, the cat died shortly after and its remains have since been sent to the CDC for testing. Who knew that a stray cat in the Northwest U.S. could have possibly been harboring bacteria that once had the potential to wipe out entire cities. Fortunately, modern medicine is on our side.
So is the re-emergence of the Plague something that we should really be concerned about? Probably not. But it never hurts to be informed.
Am I correct that in North America plague is virtually unknown in urban areas? If so it would appear the Norway rat and the common house mouse do not carry the disease. In the current case, I wonder if it wasn't the rodent's blood that carried the disease. The cat may have delivered the bite, but the cat's mouth was full of rodent blood.
Nice post, Michelle, on an interesting subject that could become important again. We need to guard our air and seaports, not with prejudice or commercial protectionism, but with knowledge and science.
We can learn a lot from history, and new techniques enable us to look back and learn ever more to correct the misconceptions of the past.
History does tend to repeat itself, but it is never quite the same, always a new twist.
The twist on future "plagues" may well be ineffective antibiotics.
Bubonic plague in Yosemite and now in Oregon. I don't recall reports of bubonic plague and massive anthrax outbreaks and massive west Nile disease all in the same year.
I know anthrax shows up if soil is excavated where infection has occurred before.
I know west Nile shows up during great mosquito weather, but during one of the greatest droughts in our history???
And now bubonic plague!
Makes you wonder what will be next?