how does yersinia pestis kill humans

A person exposed to Yersinia

pestis through the air would usually become ill in just 1 to 3 days. When bubonic plague is left untreated, plague bacteria can invade the bloodstream. When plague bacteria multiply in the bloodstream, they spread rapidly throughout the body and cause a severe and often fatal condition called septicemic plague.

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How long does it take for Yersinia pestis to cause plague?

Yersinia pestis used in an aerosol attack could cause cases of the pneumonic form of plague. One to six days after becoming infected with the bacteria, people would develop pneumonic plague.

What happens if Yersinia pestis is not treated?

Without proper treatment, the Y. pestis bacteria could spread through the bloodstream and a person could develop septicemic plague. Septicemic plague. This form of plague is the second most common. It can develop when Y. pestis bacteria spread through the bloodstream and cause a blood infection called septicemia.

How do you get Yersinia pestis?

It can develop when a person breathes in droplets of Y. pestis from an animal or person who has plague infection in the lungs. People who have bubonic or septicemic plague can also develop Y. pestis infection in the lungs.

How long does it take for Yersinia to spread?

Yersinia pestis used in an aerosol attack could cause cases of the pneumonic form of plague. One to six days after becoming infected with the bacteria, people would develop pneumonic plague. Once people have the disease, the bacteria can spread to others who have close contact with them.

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What does Yersinia pestis do to the human body?

Bubonic plague is the most common form of plague. This occurs when an infected flea bites a person or when materials contaminated with Y. pestis enter through a break in a person's skin. Patients develop swollen, tender lymph glands (called buboes) and fever, headache, chills, and weakness.

How long does the plague take to kill you?

The infection takes three–five days to incubate in people before they fall ill, and another three–five days before, in 80 per cent of the cases, the victims die. Thus, from the introduction of plague contagion among rats in a human community it takes, on average, twenty-three days before the first person dies.

How painful was the Black Death?

It killed at least a third of the population, more than 25 million people. Victims first suffered pain, fever and boils, then swollen lymph nodes and blotches on the skin. After that they vomited blood and died within three days.

How does Yersinia pestis damage the host?

pestis against host phagocytes of the innate immune system, thereby allowing it to invade more tissues and organs and cause more severe impairment. Y. pestis carries both invasive factors, which promote contact with and entry into host cells, and antiphagocytic factors that inhibit uptake by host cells.

What made the Black Death so terrifying?

Beyond the high level of mortality, what made the Black Death so terrifying for those experiencing it? It was especially horrifying because it was not just a bubonic plague, meaning that it could attack the lymphatic system and produce painful, pus-filled buboes.

How would the Black Death kill you?

Bubonic plague can be fatal if it's not treated. It can create infection throughout the body (septicemic plague) and / or infect your lungs (pneumonic plague.) Without treatment, septicemic plague and pneumonic plague are both fatal.

Why did plague masks have beaks?

De Lorme thought the beak shape of the mask would give the air sufficient time to be suffused by the protective herbs before it hit plague doctors' nostrils and lungs.

Did anyone recover from the Black Death?

In the first outbreak, two thirds of the population contracted the illness and most patients died; in the next, half the population became ill but only some died; by the third, a tenth were affected and many survived; while by the fourth occurrence, only one in twenty people were sickened and most of them survived.

Did plague doctors carry weapons?

The doctor carried a long wooden stick which he used to communicate with his patients, examine them, and occasionally ward off the more desperate and aggressive ones. By other accounts, patients believed the plague to be a punishment sent from God and requested the plague doctor whip them in repentance.

What are the virulence factors of Yersinia pestis?

pestis expresses several virulence factors, including F1 antigen, Psa, and four Yops (YopT, YopH, YopE, and YpkA) which are employed to resist phagocytosis by the surrounding professional phagocytes.

What body systems are affected by the bubonic plague?

Bubonic plague infects your lymphatic system (a part of the immune system), causing inflammation in your lymph nodes. Untreated, it can move into the blood (causing septicemic plague) or to the lungs (causing pneumonic plague).

What do Yersinia pestis eat?

Y. pestis is a chemoheterotroph, meaning that it must consume organic molecules for energy and carbon. The bacteria live in fleas, which are carried by rats, rabbits, humans and other mammals. These animals can be transported around the world with human cargo.

What does Y pestis do?

Just like a spy entering enemy territory, one of the first things Y. pestis does is go under cover. One of the molecules in its outer membrane, called lipopolysaccharide*, is a dead giveaway to your immune system. So, the bacterium cleverly modifies the structure of this molecule so it no longer alerts the immune system.

Why does Y. pestis jam?

Because it packs some serious heat, Y. pestis doesn't mind living there. During its journey, if the bacterium encounters any pesky immune cells, such as macrophages, it jams what looks like a hypodermic needle (called a " type III secretion system ") into the cell and injects several toxins.

How does the bubonic plague work?

The bacteria then migrate through the blood to your lungs, at which point you're basically cooked. But, how exactly do you die? Strangely enough, your body kills itself.

What temperature does a bacterium need to be inside a warm blooded mammal?

When it is around 37 degrees Celsius (98.6 degrees F.), the bacterium figures it must be inside a warm-blooded mammal. The bacterium then makes a beeline for your lymph nodes, immune system outposts that are constantly searching for microbial intruders.

What happens when your body kills itself?

The presence of so many bacteria in the bloodstream causes your immune system to freak out, triggering a condition called septic shock. Your body's blood vessels begin leaking, decreasing blood volume. This leads to abnormal clotting and multiple organ failure.

Does Y. pestis need iron?

Additionally, at some point, Y. pestis needs some iron. Your body has quite a bit of that, but it's wrapped up in hemoglobin and other proteins. One of these proteins, called transferrin, becomes the victim of a highway robbery. Y. pestis releases a molecule called yersiniabactin which has a high affinity for iron.

Does Y. pestis replicate?

In fact, it loves iron so much, that it is able to physically rip it away from transferrin, and then it brings the iron back to Y. pestis. Once safely inside the lymph node, Y. pestis replicates. Eventually, your immune system picks up on the fact that something is terribly wrong.

Why is the plague called the Black Death?

Plague has most famously been called "the Black Death" because it can cause skin sores that form black scabs. A plague epidemic in the 14th century killed more than one-third of the population of Europe within a few years. In some cities, up to 75% of the population died within days, with fever and swollen skin sores.

How many cases of the plague are there in the world?

Worldwide, up to 3,000 cases of plague are reported to the World Health Organization (WHO) each year, mostly in Africa, Asia and South America. To continue reading this article, you must log in.

How to prevent the spread of the plague?

If you live, work or vacation in regions where plague affects local rodent populations, here are things you can do to help prevent getting the infection and allowing plague to spread: Avoid contact with sick or dead animals, especially rodents.

How long does it take for the bubonic plague to subside?

With proper antibiotic treatment, most symptoms of uncomplicated bubonic plague will subside within two to five days. However, swollen buboes can remain for several weeks. Recovery from more severe septicemic plague and pneumonic plague usually takes longer.

How rare is the Pneumonic Plague?

With appropriate treatment, however, 75% to 80% of people survive. Pneumonic plague. This form of plague is currently very rare. It happens when Y. pestis bacteria infect the lungs and cause pneumonia.

What are the symptoms of the Septicemic Plague?

The first symptoms of septicemic plague can include nausea, vomiting, diarrhea and abdominal pain.

How is a plague transmitted?

In the United States, it is most commonly transmitted to humans by the bite of an infected rat flea ( Xenopsylla species).

What is the second most common plague?

Septicemic plague. This form of plague is the second most common. It can develop when Y. pestis bacteria spread through the bloodstream and cause a blood infection called septicemia. It can also happen if Y. pestis spreads from a bubo or from the lungs into the bloodstream.

How long does it take for a person to recover from a flea bite?

About 2 to 6 days after the flea bite, a person with bubonic plague develops a high fever, chills, muscle aches, headache and extreme weakness and within another 24 hours, 1 or more buboes appear. With prompt treatment of appropriate antibiotics, over 90% of people will survive.

What is the fatality rate of pneumonic plague?

Untreated, the fatality rate of pneumonic plague approaches 100%. Sudden onset of fever, chills, weakness, headache, and buboes will occur, typically followed by nausea and vomiting. The bubo is an extremely painful bump resulting from a swollen, tender lymph node, usually in the groin, armpit, or neck.

What is pneumonic plague?

Pneumonic plague is the result of Y. pestis infection of the lungs. Primary pneumonic plague results from inhalation of Y. pestis bacteria and would be the expected form of disease following an aerosol attack with Y. pestis.

How many cases of pneumonic plague were there in 1970?

pestis in an aerosol cloud over a city of 5 million might result in 150,000 cases of pneumonic plague.

How many cases of the Septicemic Plague are there in the world?

Plague is recognized by public health experts as a re-emerging infectious disease. Worldwide incidence has reached approximately 2,000 to 3,000 reported cases each year.

What are the three types of plagues?

Three forms of naturally occurring plague infection exist: 1 Pneumonic plague is the result of Y. pestis infection of the lungs. Primary pneumonic plague results from inhalation of Y. pestis bacteria and would be the expected form of disease following an aerosol attack with Y. pestis. Secondary pneumonic plague can occur if bubonic or septicemic plague goes untreated and the plague bacteria are allowed to spread to the lungs. 2 Bubonic plague is the most common form of naturally occurring plague and is typically acquired through the bite of an infected flea. Bubonic plague is characterized primarily by swollen, tender lymph nodes (called buboes). 3 Septicemic plague is the result of plague bacteria multiplying in the blood and disseminating throughout the body. Septicemic plague usually occurs as a result of untreated bubonic or pneumonic plague.

What is the most common form of plague?

Bubonic plague is the most common form of naturally occurring plague and is typically acquired through the bite of an infected flea. Bubonic plague is characterized primarily by swollen, tender lymph nodes (called buboes).

How long does it take to diagnose the plague?

Diagnosis of plague is based on clinical presentation of symptoms and confirmed by laboratory testing, which usually takes 24 to 48 hours . There are no widely available rapid diagnostic tests for plague. The first sign of a bioterrorist attack with plague would most likely be a sudden surge of patients presenting at hospitals and doctors' offices with symptoms of severe pneumonia and sepsis.

Which plague is the most serious?

Pneumonic plague is the most serious form of the disease and is the only form of plague that can be spread from person to person (by infectious droplets). Forms of plague. Top of Page.

What happens when the bubonic plague is left untreated?

When bubonic plague is left untreated, plague bacteria can invade the bloodstream. When plague bacteria multiply in the bloodstream, they spread rapidly throughout the body and cause a severe and often fatal condition called septicemic plague.

What is the first sign of the plague?

Skin and other tissues may turn black and die, especially on fingers, toes, and the nose. Septicemic plague can occur as the first symptoms of plague, or may develop from untreated bubonic plague. This form results from bites of infected fleas or from handling an infected animal.

How do fleas get infected?

Fleas become infected by feeding on rodents, such as chipmunks, prairie dogs, ground squirrels, mice, and other mammals that are infected with the bacterium Yersinia pestis. Fleas transmit the plague bacteria to humans and other mammals during a subsequent feeding. The plague bacteria survive briefly ...

How long does it take for the plague to incubate?

What is the incubation period for plague? A person usually becomes ill with bubonic plague 2 to 6 days after being infected. Someone exposed to Yersinia pestis through the air would become ill within 1 to 3 days. When bubonic plague is left untreated, plague bacteria can invade the bloodstream.

How is the plague diagnosed?

How is plague diagnosed? The first step in plague diagnosis is evaluation by a health worker. If the health worker suspects plague, samples of the patient’s blood, sputum, or lymph node aspirate are sent to a laboratory for testing .

What is the disease that affects rodents, certain other animals, and humans?

Plague is an infectious disease that affects rodents, certain other animals, and humans. It is caused by the Yersinia pestis bacteria. These bacteria are found in many areas of the world, including the United States.

How do people get the Pneumonic Plague?

If these bacteria-containing droplets are breathed in by another person they can cause pneumonic plague. Typically this requires direct and close contact with the person with pneumonic plague. Transmission of these droplets is the only way that plague can spread between people. This type of spread has not been documented in the United States since 1924, but still occurs with some frequency in developing countries. Cats are particularly susceptible to plague, and can be infected by eating infected rodents. Sick cats pose a risk of transmitting infectious plague droplets to their owners or to veterinarians. Several cases of human plague have occurred in the United States in recent decades as a result of contact with infected cats.

How do you get the plague?

Transmission. The plague bacteria can be transmitted to humans in the following ways: Flea bites. Plague bacteria are most often transmitted by the bite of an infected flea. During plague epizootics, many rodents die, causing hungry fleas to seek other sources of blood.

What is the term for the long term reservoir of bacteria?

These infected animals and their fleas serve as long-term reservoirs for the bacteria. This is called the enzootic cycle. Occasionally, other species become infected, causing an outbreak among animals, called an epizootic. Humans are usually more at risk during, or shortly after, a plague epizootic.

What animals are affected by the plague?

Many types of animals, such as rock squirrels, wood rats, ground squirrels, prairie dogs, chipmunks, mice, voles, and rabbits can be affected by plague. Wild carnivores can become infected by eating other infected animals.

Can plague spread between people?

Transmission of these droplets is the only way that plague can spread between people. This type of spread has not been documented in the United States since 1924, but still occurs with some frequency in developing countries. Cats are particularly susceptible to plague, and can be infected by eating infected rodents.

Can humans get infected by the plague?

Humans can become infected when handling tissue or body fluids of a plague-infected animal. For example, a hunter skinning a rabbit or other infected animal without using proper precautions could become infected with plague bacteria. This form of exposure most commonly results in bubonic plague or septicemic plague.

Can cats get plague?

Cats are particularly susceptible to plague, and can be infected by eating infected rodents. Sick cats pose a risk of transmitting infectious plague droplets to their owners or to veterinarians. Several cases of human plague have occurred in the United States in recent decades as a result of contact with infected cats.

What Is It?

• Plague is caused by Yersinia pestis bacteria. It can be a life-threatening infection if not treated promptly. Plague has caused several major epidemics in Europe and Asia over the last 2,000 years. Plague has most famously been called "the Black Death" because it can cause skin sores that form black scabs. A plague epidemic in the 14th century kill...

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What Is The Plague (Yersinia Pestis)?

• Plague is caused by Yersinia pestis bacteria. It can be a life-threatening infection if not treated promptly. Plague has caused several major epidemics in Europe and Asia over the last 2,000 years. Plague has most famously been called "the Black Death" because it can cause skin sores that form black scabs. A plague epidemic in the 14th century kill...

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Symptoms

Diagnosis

Expected Duration

Prevention

Treatment

When to Call A Professional

Prognosis

Further Information