Yersinia pestis – Infection, Symptoms, Diagnosis, and Treatment

The bubonic plague is a bacterial disease that is considered one of the most lethal in history. Recorded pandemics of the plague reach back to 541 A.D. and minor epidemics can still be found around the world (Plague). The plague consists of a bacterium called Yersinia pestis. This bacterium has the ability to mutate quickly and can easily destroy the immune system of the infected person, “it does this by injecting toxins into defense cells such as macrophages that are tasked with detecting bacterial infections. Once these cells are knocked out, the bacteria can multiply unhindered.” (Plague) The bubonic plague has a number of symptoms ranging from a headache to seizures. The most distinguishable

I was observing the spread of the plague right before my eyes. I knew how the three types of plague were transmitted but the humans did not. The three types were the Bubonic, Pneumonic and Septicemic plague. The Bubonic plague was the most common plague in medieval Europe. It was transmitted by infected fleas that were carried by rats, when the rat died the flea would jump to a human to feed from their blood. The human bitten by the flea, was then infected and faced certain death, the flea would then find a new human to feed off. The Pneumonic plague, being the second most common type in medieval Europe, was far more deadly and contagious than the Bubonic plague. The Plague would attack a human's respiratory system and was spread through the air by a victim's cough. The last type of plague was the Septicemic, it was the rarest and deadliest form of the Black Death. The Septicemic plague was also spread by fleas, like the Bubonic plague, but moved directly to a human's

Apparently this plague is is very deadly, and came to us by rats during sea travel through the Mediterranean. The Black Death brought three specific plagues to my village: bubonic plague, pneumonic plague, septicemic plague. These plagues have each come with there own symptoms. The bubonic plague’s symptoms

patients. Because they were paid by the state, the doctors were able to treat both the

What is the plague? The plague or referred to as the Black Death, according to the CDC (2015), “is a disease that affects humans and other mammals and caused by the Yersinia pestis bacteria. Humans usually get plague after being bitten by a rodent flea that is carrying the plague bacterium or by handling an animal infected with plague”. There are three categories of a plague. There is the bubonic plague, which is the most common form. With this form bacteria infects the lymph system and causes it to become inflamed. Symptoms of this type of plague are fever, headache, chills, and swollen and tender lymph nodes, which are called buboes. Then there is the Septicemic, which occurs when the bacteria multiply in the blood. Symptoms of this type of plague are fever, chills, extreme weakness, abdominal pain, shock, and possibly bleeding into the skin and other organs. Also, skin and other tissues may turn black and die, especially fingers, toes and the nose (CDC, 2015). Then there is the Pneumonic Plague, which is the most serious form of plague and occurs when Y. pestis bacteria infect the lungs and cause pneumonia (NIH, 2015). This is the only form of the plague that can be transmitted human to human. Symptoms of this form of the plague are ever, headache, weakness, and a rapidly

The cause of the Bubonic Plague was by a living host that transport from one animal to another animal, which is called a vector-borne illness. A Xenopsylla Cheopis, an oriental rat flea, was the vector. When the flea bites, the wound is injected by infected blood and the body’s natural response to inflammatory decreases. The bacteria travels using white blood cells to find the closes lymph node, then spreads and multiplies. Lymph nodes are important because they carry fluids, waste material and nutrients to body tissues and the bloodstream. If they swell up, they can’t filter out the bad bacteria in the body. In the first few days of catching the plague, a person experiences large swelling in the lymph nodes which causes the body immune to

The causes of the Black Death – the flea, the rat, and the bacillus Yersinia pestis– have been labeled the “unholy trinity” (Boeckl). The flea is able to live in environmental conditions of about 74° Fahrenheit and 60% humidity (Ibid). Before the Black Death reached Europe, they were experiencing those same types of weather conditions. The rat flea, Xenopsylla cheopis and the human flea, Pulex irritans, are both capable of transmitting plague (Boeckl). Sometimes, an infected flea cannot ingest blood because Yersinia pestis obstructs its digestive tract. The blockage causes a flea to regurgitate into a bitten host rather than ingest the host’s blood, thereby infecting the host with plague (Boeckl). Unable to eat, the famished flea will bite with more frequency, accelerating the spread of plague. A flea can be carrying Yersinia pestis without it blocking the flea’s digestive tract, in which case the flea does not transmit plague when it bites a host. Also, Yersinia pestis can only enter a victim through a bite, as the bacilli cannot pass through intact skin (Gottfried).

In the lymphatic system, the lymph nodes acts as filters, catching substances harmful to the body, like toxins, bacteria, cancer cells, and viruses. The plague directly targeted this form of defense. The plague has three forms of infection, based on how the bacteria were transmitted to the individual. These forms are bubonic, septicaemic and pneumonic. The Bubonic form was the most common, especially during the 14th century; this form of the plague came directly from flea bites. With the Bubonic plague, the bacteria travel to the lymph nodes where it begins to multiply. The lymph node begins to become inflamed. The swollen lymph nodes are called “buboes”. The swollen nodes soon begin to cause sores, and if left untreated, the Bubonic plague can turn into the septicaemic form. The septicaemic form is a result of the Y. pestis entering the bloodstream. Since the bacteria are overwhelming the lymph nodes, and causing them to swell, the immune system is compromised. Individuals with the septicaemic form of the plague suffer with a high fever and eventually die of multiple organ failure. The last and most fatal form of the plague is the pneumonic plague. When infected with the pneumonic plague, the individuals develop a cough due to high levels of mucus buildup in the lungs, about 99% of those who contract this form die. Although the disease is fatal if left untreated, there is

Plague, was a term that was applied in the Middle Ages to all fatal epidemic diseases, but now it is only applied to an acute, infectious, contagious disease of rodents and humans, caused by a short, thin, gram-negative bacillus. In humans, plague occurs in three forms: bubonic plague, pneumonic plague, and septicemic plague. The best known form is the bubonic plague and it is named after buboes, or enlarged, inflamed lymph nodes, which are characteristics of the plague in the groin or neck or armpit. Bubonic plague can only be transmitted by the bite of any of numerous insects that are normally parasitic on rodents and that seek new hosts when the original host dies. If the plague is left untreated

Now, what was the plague? It wasn’t just one disease, it was a combination of three bacterial strains: bubonic, pneumonic, and septicemic. If you got it, the least dangerous was the bubonic. You would get a high fever, chills, buboes, rapid heartbeat and vomiting, within 3 to 6 days of having this, up to 50-80% of the victims died. Pneumonic, which was less common, infected the respiratory system and killed almost all its victims taking only hours to do so. Last, was septicemic, this type infected the bloodstream, which ended up killing all who got it. But, either way, whichever form you got you would still end up dying. And although this happened in the 14th century, this was not the first time the plague had gone around. It went to Europe in the 18th century and into Africa and Asia the 20th century.

In this paragraph I will be discussing the general context of the Black Death. The plague is believed to have been caused by fleas on rats. There are three different types of plague bubonic, pneumonic, and septicemic. Even though all bad septicemic is the worst because it affected the bloodstream. The second to worst is the pneumonic it affects the respiratory system which killed most of the victims. Then there is the bubonic plague which is the most

Bubonic plague is an infectious disease that is spread by the bacteria Yersinia pestis. These bacteria remain in a dormant state primarily in a rat flea’s foregut. Once the flea has bitten a victim it regurgitates the contents in its foregut into the bite location. Once the bacterium has entered into a mammal’s warm body it begins to reproduce and spread throughout the mammal’s body. The reproduction of this bacterium creates large painful swollen lymph nodes which are called buboes. Once these buboes get large enough they begin to ooze infected body fluid so that any contact between an infected person and a healthy person will facilitate the spread of this disease. (The Mayo Clinic Staff, 2012)

In the case of weaponized aerosol release of Yersinia pestis bacteria would cause primary pneumonic plague in the exposed. An infected individual from this attack has the potential to cause a secondary spread from person to person, but would not cause secondary pneumonic plague as the transmission originally occurred in an aerosolized form and would sustain cycles of human transmission (from person to person) independent of secondary zoonotic vectors such as through flea, tick, or rodent bites (Gani, R., & Leach, S., 2004).

There are three types of plague disease and each one of them has different symptoms. The first type of plague disease, the most popular type of disease, called Bubonic plague. According to Patient Care & Health Information in Mayo Clinic, its symptoms start to appear with less than 10 days after someone got bitten by an infected flea. The symptoms start with buboes, swollen lymph nodes, appear in some places in the body like neck, groin, or armpit. Also, buboes’ size is almost like a chicken egg size. A headache, muscle ache, chills and fever are the other sings of this type of disease (2015). The other type of plague disease is a result of plague bacteria multiplies in the blood which known as Septicemic plague. According to CDC, shock,

The Bubonic Plague and a variation called the septicemic plague was spread throughout Europe by oriental rats that carried infected fleas. Little is known to why the infection never seemed to affect the carrier rats. Infected fleas were being starved by the infection, so they began feasting upon the people they came into contact with. These fleas coming into contact with any human being would infect the human with the disease. These people were now carriers of the Bubonic plague or Black Death. These infected people would then spread the disease by coughing or coming into direct contact with another human being. However, this disease, since not being transmitted via rat would now be called the Pneumonic Plague. (www.insecta-inspecta.com).