how does a plague run its course

How does a person get the plague?

When a person has plague pneumonia, they may cough droplets containing the plague bacteria into air. 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.

What is the mode of transmission of plague?

Transmission. 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. People and animals that visit places where rodents have recently died from plague are at risk of being infected from flea bites.

How does the plague bacteria maintain its existence?

The bacteria that cause plague, Yersinia pestis, maintain their existence in a cycle involving rodents and their fleas. In urban areas or places with dense rat infestations, the plague bacteria can cycle between rats and their fleas.

What is the Black Plague?

The plague is a serious bacterial infection that can be deadly. Sometimes referred to as the “black plague,” the disease is caused by a bacterial strain called Yersinia pestis. This bacterium is found in animals throughout the world and is usually transmitted to humans through fleas.

What are the symptoms of the plague?

These include rashes, nausea, sensitivity to light, diarrhea and coughing. Swollen, painful buboes appear consistently in most accounts. This is one of the reasons why plague takes the blame for so many pandemics.

What is a bubonic plague smear?

A bubonic plague smear, prepared from a lymph removed from an adenopathic lymph node, or bubo, of a plague patient, demonstrates the presence of the Yersinia pestis bacteria that causes the plague in this undated photo. Centers for Disease Control and Prevention/Getty Images

How many people died in the Justinian plague?

Justinian's Plague lasted from 542-546. It claimed about 100 million victims in Europe, Asia and Africa. The Black Death moved across Europe in the 1300s, killing about a third of the continent's population. In total, there were about 50 million deaths in Europe, Asia and Africa.

Why did people wear masks for plague?

Plague doctors, who usually had little to no medical training, wore masks stuffed with herbs to filter the air. In some cities, people blamed dogs and cats for the illness. The resulting slaughter of rats' natural predators may have encouraged the spread of the disease.

What caused the Black Death?

During each of these epidemics, no one knew what caused the disease or how it spread. During the Black Death, for example, many blamed the illness on toxic miasmas, so people focused on keeping bad air away. Plague doctors, who usually had little to no medical training, wore masks stuffed with herbs to filter the air.

When was the last plague in England?

Workers transport dead bodies during the Great Plague of London. The Great Plague, lasting from 1665 to 1666, was the last major epidemic of the bubonic plague to occur in England duncan1890/Getty Images

Is the plague a virus?

Advertisement. People have reacted to the appearance of each of these diseases with fear and dread. A major outbreak of plague today would spark a similar reaction. But unlike many of today's newsmakers, plague comes from an old bacterium rather than a new virus.

How does the plague spread?

How plague spreads. People usually get plague through the bite of fleas that have previously fed on infected animals like mice, rats, rabbits, squirrels, chipmunks, and prairie dogs. It can also be spread through direct contact with an infected person or animal or by eating an infected animal. .

Where does the plague occur?

Today, most human cases of the plague occur in Africa though they do appear elsewhere. The countries in which the plague is most common are Madagascar, the Democratic Republic of Congo, and Peru. in the rural southwest and, in particular, in Arizona, Colorado, and New Mexico.

What is the name of the disease that occurs when bacteria enter the bloodstream?

Septicemic plague. When the bacteria enter the bloodstream directly and multiply there, it’s known as septicemic plague. When they’re left untreated, both bubonic and pneumonic plague can lead to septicemic plague.

How to check for the plague?

To check for bubonic plague, your doctor will use a needle to take a sample of the fluid in your swollen lymph nodes.

What are the symptoms of the bubonic plague?

fever and chills. headache. muscle pain. general weakness. seizures. You may also experience painful, swollen lymph glands, called buboes. These typically appear in the groin, armpits, neck, or site of the insect bite or scratch. The buboes are what give bubonic plague its name.

What is the most common form of plague?

The most common form of plague is bubonic plague. It’s usually contracted when an infected rodent or flea bites you. In very rare cases, you can get the bacteria from material that has come into contact with an infected person.

How long does it take for the plague to show symptoms?

Signs and symptoms of the plague. People infected with the plague usually develop flu-like symptoms two to six days after infection. There are other symptoms that can help distinguish the three forms of the plague.

What is the plague?

the bite of infected vector fleas. unprotected contact with infectious bodily fluids or contaminated materials. the inhalation of respiratory droplets/small particles from a patient with pneumonic plague. Plague is a very severe disease in people, particularly in its septicaemic (systemic infection caused by circulating bacteria in bloodstream) ...

What is the cause of the plague?

Plague is caused by the bacteria Yersinia pestis, a zoonotic bacteria usually found in small mammals and their fleas. People infected with Y. pestis often develop symptoms after an incubation period of one to seven days. There are two main clinical forms of plague infection: bubonic and pneumonic. Bubonic plague is the most common form ...

How is the Bubonic Plague transmitted?

Plague is transmitted between animals and humans by the bite of infected fleas, direct contact with infected tissues, and inhalation of infected respiratory droplets.

How severe is the plague?

Plague can be a very severe disease in people, with a case-fatality ratio of 30% to 60% for the bubonic type, and is always fatal for the pneumonic kind when left untreated. Antibiotic treatment is effective against plague bacteria, so early diagnosis and early treatment can save lives. From 2010 to 2015 there were 3248 cases reported worldwide, ...

What are the preventive measures for zoonotic plague?

Preventive measures include informing people when zoonotic plague is present in their environment and advising them to take precautions against flea bites and not to handle animal carcasses. Generally people should be advised to avoid direct contact with infected body fluids and tissues.

What is the most common form of plague?

There are two main forms of plague infection, depending on the route of infection: bubonic and pneumonic. Bubonic plague is the most common form of plague and is caused by the bite of an infected flea.

How many deaths from the plague in 2015?

From 2010 to 2015, there were 3248 cases reported worldwide, including 584 deaths. Historically, plague was responsible for widespread pandemics with high mortality.

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.

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.

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.

Can fleas cause the plague?

Dogs and cats may also bring plague-infected fleas into the home. Flea bite exposure may result in primary bubonic plague or septicemic plague. Contact with contaminated fluid or tissue.

Where did the plague start?

The first outbreaks appear in 1330 in Central Asia, breaking into India and East China , then heading west through the Middle East to North Africa.

Why did people walk down the street with a bird-shaped mask?

All this because a medieval prejudice considered that the plague was spread by birds.

What is the most destructive disease?

The plague can be considered the most destructive disease that had ever affected mankind. The history of plague pandemics is difficult to reconstruct, but from the distant past, we have had a few descriptions of the symptoms. It is difficult today to say whether it was the plague or other diseases. Ancient Egypt, the Far East, ancient Greece, imperial Rome, and the Byzantium were swept by waves of pandemics.

Who discovered the speed of the plague?

The speed of plague. In 1894, Alexander Yersin and another scientist separately identified Y. pestis during an epidemic in Hong Kong. Years later the bacterium was given his name. Yersin also connected his discovery to the pestilence that swept Europe during the Black Death, an association that has stuck.

When was the last rat plague?

The last rat-borne plague epidemic in the U.S. occurred in 1925; wild rodents have since become the primary source for infections. However, rat-associated outbreaks continue to occur in developing countries, according to the CDC.

How long does it take for a flea to grow in a rat?

Once a flea bites a rat infected with plague, the pathogen Y. pestis grows in its gut. After about two weeks , the bacteria block the valve that opens into the flea's stomach. The starving flea then bites its host, by now probably a new, healthy rat or a person, more aggressively in an attempt to feed.

How much of the population was wiped out by the Black Death?

Fast, furious and unfamiliar. Not only has the disease slowed down, it also seems to have become more restrained. The Black Death wiped out at least 30 percent of Europe's population at the time. But the peak of the modern pandemic, in India, killed less than 2 percent of the population, DeWitte has calculated from census data.

What is the mutation of the Black Death?

Two other proponents of the virus theory, Susan Scott and Christopher Duncan of the University of Liverpool in the United Kingdom, have pointed to a possible genetic legacy left by a viral Black Death: a mutation, known as CCR5-delta32, found among Europeans, particularly those in the north.

When did the Black Death happen?

A depiction of the black death from a 15th century Bible. The Black Death arrived in London in the fall of 1348, and although the worst passed in less than a year, the disease took a catastrophic toll. An emergency cemetery in East Smithfield received more than 200 bodies a day between the following February and April, ...

Was the plague responsible for the Black Death?

And if plague isn't responsible for the Black Death, scientists wonder what could've caused the sweeping massacre and whether that killer is still lurking somewhere. Now, a new study using bone and teeth taken from East Smithfield adds to mounting evidence exhumed from Black Death graves and tantalizes skeptics with hints at the true nature ...

Signs and Symptoms

Where Is Plague Found?

Diagnosing Plague

Treatment

Prevention

Vaccination

Managing Plague Outbreaks

• Confirmation of plague requires lab testing. The best practice is to identify Y. pestis from a sample of pus from a bubo, blood or sputum. A specific Y. pestis antigen can be detected by different techniques. One of them is a laboratory validated rapid dipstick test now widely used in Africa and South America, with the support of WHO.

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Surveillance and Control

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