IndexIntroductionOverviewInfection and TransmissionTreatment, Detection, and PreventionHistoryConclusionIntroductionThe history of medicine has come a long way, from the art of bleeding to surgeries so incomprehensibly refined that only the most trained professionals could think of conducting. The art of medicine probably begins with the understanding of disease and the understanding that science trumps religion in medical terms. A disease initially believed to be God's will, the plague was nicknamed the Black Death, a bacterium responsible for the death of around 60% of the European population in the Middle Ages and still widespread today in many developing countries, where sanitation services are poor . and rat populations increase dramatically. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay Overview Bubonic plague is, in fact, the least deadly of the three forms of plague caused by the same bacterium, known as Yersinia Pestis, (Y Pesti). Bubonic plague, probably the least deadly of the three plagues, characterized by buboes, which are infected lymph nodes that swell with fluid and pus to fight the infection, often kills within eight to ten days of infection, because the body is not better able to fight the infection. to contain the bacteria and leads to dangerous measures to contain the disease. Lymph nodes are found around the neck, armpits, groin and other areas of the body, and swelling and darkening of these areas are the first definite symptoms of plague. On the right is an image of a person infected with bubonic plague. The lymph nodes in the knee have become infected and are starting to swell. Septicemic plague, the second form of the plague is a blood infection, where the death rate is about 95% within two days. Often, untreated bubonic plague progresses to septicemic plague, where the blood becomes poisoned. The third form, pneumonic plague, is the most devastating and is the result of a Y. Pestis lung infection, which kills the patient in as little as a day, sometimes without even showing any symptoms of infection. Unfortunately, these plagues, when they reached pandemic levels, killed between 30 and 60 percent of medieval Europe and approximately 75 million people worldwide. Infection and Transmission The Y. Pestis bacterium is most often found inside a rat flea, a parasite that affects rats. When the rat is bitten by the flea, an asymptomatic carrier of the pathogen, the bacteria are transferred to the rat. This is believed to have been the cause of many of the plagues in 17th century Europe, where three plagues in 1606, 1636 and the Great Plague, 1665-1666, caused unprecedented numbers of deaths among rats, due to their bodies also succumb to the disease. Because of this, the fleas would find other hosts to feed on, thus bringing them to humans to feed on. Once humans die, the flea will change hosts from the dead rat to other animals, such as dogs, cats, and sometimes humans. An image of the rat flea is shown, with the black mass inside its intestine, identified as Y. Pestis, responsible for the plague. When a human is bitten by a flea, the germ, which resides in the flea's intestine, is regurgitated by the flea into the human. Once inside the human being, Y. Pestis will realize that it is inside a warm-blooded organism, as it is able to detect the external temperature around its membrane. Warm-blooded organisms have a body temperature between 97 and 104 degrees Fahrenheit, or approximately 36 to 40 degrees Celsius. Therefore, once this is achievedtemperature, Y. Pestis will begin to invade the body, knowing its location within a warm-blooded organism. First, Y. Pestis will modify an endotoxin found within the membrane of its composition, also known as lipopolysaccharide. This molecule is made up of some lipid (fat) and a polysaccharide, which is a mixture of carbohydrates and sugars. When the bacteria detects that it is inside a warm-blooded organism, it will change the composition of the endotoxin's molecular structure, to camouflage itself. Endotoxins are a dangerous substance for the body and are a distinctive feature of many harmful bacteria. Therefore, by hiding this marker, the white blood cell will no longer realize that the bacterium is an enemy and will therefore leave it alone. Y. Pestis, still has a method of destroying white blood cells, as they will inject a variety of toxins into the white blood cells, using a type III secretion system (T3SS) shown below in an example featuring a different form of bacteria, note such as salmonella typhimurium, which uses similar injectors to inflict damage on the body. Specifically, Y. Pestis uses them to neutralize any attackers or passing white blood cells, without warning, simply to facilitate their travel through the body and further cripple the body's defenses. The goal of Pestis is to reach the lymph nodes, where the first definite symptoms, the buboes, begin. Traveling through the circulatory system, Y. Pestis has a path connected directly to the lymph nodes, but also to many other organs, such as the lungs, which will then cause the 100% lethal pneumonic plague. During this journey, Y. Pestis will need a mineral that the healthy human body has in abundance. To reproduce and live the Y. Pestis requires a source of iron, used in the body as a component of hemoglobin, which is found in red blood cells and is responsible for transporting oxygen to various points in the body. To steal this iron from the body, Y. Pestis uses a molecule classified as a siderophore. Siderophores are strongly attracted to iron, and those used by Y. Pestis are called yersiniabactin. Yersiniabactin attacks a specific protein called transferrin, stripping iron from proteins, which are busy transporting iron around the body. Transferrin is the most potent carrier for transporting iron through the body and to cells, and therefore contains the greatest amount of iron that Y. Pestis can absorb. Once yersiniabactin is able to absorb iron from the body, it returns to the bacteria and uses the stolen iron to keep the pathogen alive and strong. In fact, this iron capture is so massive and harmful to health, that some of the symptoms felt by the body are actually symptoms of iron deficiency, caused by bacteria. For example, the pathogen does not directly affect the head, except for the lymph nodes located on the face, yet one of the hallmarks of bubonic plague is terrible headaches and weakness. This is because the body has lost so much iron, that the blood is slowly losing its ability to carry oxygen, starving the brain and causing headaches in the brain and weakness in the muscles, including the heart, once again to due to lack of oxygen in muscle tissue. Once it arrives in the lymph nodes located throughout the body, Y. Pestis is sure to reproduce within the lymph nodes, effectively destroying many of the white blood cell locations. With the help of its molecularly rearranged cell membrane, Y. Pestis can hide from the enemy and destroy the lymphatic system from the inside. The bacteria reproduce exponentially and when the lymphatic system realizes the danger, thebody reacts, creating pus and swelling at the site of the infection, the lymph nodes. However, the body will be overwhelmed by the power of the bacteria and will be pushed into a powerful weapon, with enormous potential for collateral damage. This often kills the patient and is known as septic shock. This is when the body produces a large amount of cytokines, which are used as a beacon to bring white blood cells to a certain area to concentrate their numbers. When white blood cells attack, however, they can also attack tissues and organs, causing organ failure and massive internal and external bleeding. This septic shock is the same cause of death in Ebola patients and is also known as cytokine storm. Treatment, detection and prevention Fortunately, with the development of modern drugs, especially antibiotics, which are used in many bacterial infections, Y. Pestis is treatable, but only within the framework of early administration of antibiotics, especially aminoglycosides, such as doxycycline, a powerful antibiotic used as a last-ditch effort to fight bacterial pneumonia or staph infections. However, the use of antibiotics is somewhat controversial, as inappropriate and excessive use of antibiotics contributes to the growth of “superbugs,” which are immune to one or more forms of antibiotics. However, in scenarios where plague or similarly dangerous infections are discovered, antibiotics are a necessity to save lives. Plague prevention is also an important aspect of staying safe, as it is safer to follow these procedures to prevent even the most dangerous septicemic and pulmonary plagues. A map representing the natural possibility of finding the three forms of plague. Countries such as Argentina and China, which have large rodent infestations, especially in urban areas, where breeding grounds and food are abundant for these rats. It is therefore advisable to be careful when traveling in these areas, especially during spring, when animals often breed, increasing the number of rats. With a gestation period of approximately 21 days, the brown rat can have up to 5 litters per year, as early as 5 weeks after birth. When these animals or their fleas bite a human, the plague infects them. However, like septicemic plague, infection from other humans is actually rare. The greatest possibility of contracting the plague is through the flea. The urban rat flea thrives in areas of high rat populations, incubating and potentially causing epidemics. Plague is also found in the wild, among the wild rat population, and is able to reproduce freely and without human interference. Fortunately, if we remain vigilant about the dangerous number of potentially infected rats, the chances of infection are significantly reduced. However, unlike other forms of plague, pneumonic plague is very contagious, and combined with the fact that the incubation period of this disease is only 24 hours, containing an epidemic would prove very difficult, as those who show no symptoms they could further spread the epidemic further. Although treatment is easily available in developed countries, prevention is also needed to prevent epidemics from occurring. Vaccines are easily available but are not even recommended by the WHO, as the chances of the plague developing in developed countries are very low and therefore not necessary. However, for those who are frequently in contact with the disease, it is important to be vaccinated against this disease, as even the slightest contact with individuals suffering from pneumonic plague could result in an epidemic or death. It is also important to remember not to kill rodents before you have.