Rat diseaseFabian Dupont is a freelance writer for NetDoktor's medical editorial team. The human medicine specialist has already been sent to Belgium, Spain, Rwanda, the USA, Great Britain, South Africa, New Zealand and Switzerland, among other countries, for scientific work. His doctoral work focused on tropical neurology, but he has a special interest in international health science (public health) and communicating medical ies in an understandable way.
Pest is a serious infectious disease that can be fatal. The trigger is the bacterium Yersinia pestis, which is transmitted to humans by rat fleas. The plague no longer plays a role in Europe, but it does in some regions of Africa, Asia, and South, Central, and North America. Read how to protect yourself from infection in such risk areas and how the plague is treated!
What is plague? Highly contagious infectious disease transmitted by rodent fleas. No longer plays a role in Europe today. Symptoms: Depending on the form z. B. high fever, chills, swollen lymph nodes, black/bluish skin coloration, bloody sputum
Cause: Caused by the bacterium Yersinia pestis, which is transmitted by flea bites and can also be passed on from person to person. Rarely, the infection occurs through direct contact with infected rodents. In pneumonic plague, droplet infection is the main mode of transmission. Risk factors are u. a. Poor hygiene standards.
Prognosis: good if treatment is started early, otherwise the disease is usually fatal.
The times when the plague ("Black Death") wiped out entire villages are fortunately over. Today, the infectious disease no longer plays a role in Europe. It is caused by the
bacterium Yersinia pestis. Rodents like rats. Mice are the reservoir of the pathogen. The bacterium can be transmitted from animals to humans via fleas. Rarely, people are infected directly from diseased rodents. Diseases that, like plague, are transmissible from vertebrates (such as rats) to humans (and in the opposite direction) are called Zoonoses.
People infected with plague can also pass the pathogen on to other people. This happens especially with pneumonic plague. It is transmitted via droplet infection.
A vaccine against plague is not available in Germany.
Plague: contained but not eradicated
The risk of contracting plague is especially high in areas where there are plague-infected wild rodents. However, according to the Robert Koch Institute, this is only present in limited Endemic areas in Africa, Asia, tropical Central and South America, and the southwestern United States. The spread of the plague is favored when many people live together in small spaces under poor hygienic conditions.
However, large epidemics and pandemics, which claimed millions of victims in the Middle Ages, no longer occur today.
Between 2010 and 2015, the World Health Organization (WHO) recorded 3 cases of plague worldwide.248 plague cases, including 584 deaths. However, this figure is very inaccurate, as more than 80 percent of infections occur in Africa, where not all cases are reported to the WHO. Incidentally, in Germany there is also an obligation to report any suspicion of plague, proven illnesses and deaths from plague in accordance with the Infection Protection Act (IfSG).
Plague is one of the four quarantine diseases, along with cholera, smallpox, and yellow fever, as defined by the World Health Organization (WHO). These diseases have a particularly threatening course of disease and are extremely contagious.
The period between infection with the plague pathogen and the appearance of the first symptoms (incubation period) varies considerably. It ranges from a few hours to up to seven days.
Basically, there are three different main forms of plague in humans, some of which have different plague symptoms.
The bubonic plague, also Bubonic plague or Black death called plague, is the most common and best known form of plague. It is generally only transmitted through flea bites. As a rule, the first symptoms appear two to six days after infection:
– high fever – chills – headache – general feeling of weakness
Small blisters sometimes form at the site where the plague bacteria have entered the skin via a flea bite. Sometimes a mild red skin rash develops in later stages. The plague pathogens migrate to the neighboring lymph nodes, which swell due to the infection and can be easily palpated. The swollen regions are hard and painful in bubonic plague. The groin, armpit and neck, where the major lymph node stations are located, are often affected. As the disease progresses, it spreads. Even more distant lymph nodes swell up.
As with a bruise, the lymph node swellings turn blue within a few days, creating the typical image of dark bumps in plague sufferers. Rarely they open. Empty highly infectious secretions.
Rodent fleas carrying the pathogen get onto the skin of humans. After the flea bite, the pathogens spread through the lymphatic system.
If the lymph nodes bleed in, complications can arise. Because then there is a risk of bacteria getting into the blood or lungs. So-called plague sepsis or pneumonic plague can then result. Both forms of the disease are severe. Often fatal.
The pneumonic plague develops either as a complication of the bubonic plague or as "independent" Disease after transmission of the plague pathogen via droplet infection: Sick people spread tiny droplets of secretion into the ambient air when they speak, cough or sneeze. These droplets contain plague bacteria and are highly contagious. When healthy people inhale them, the bacteria enter the lungs directly and cause pneumonic plague.
The first pneumonic plague symptoms develop just a few hours after the plague pathogen reaches the lungs. At first, the patient suffers only from fever, may have chills and/or headache and feels generally weak. On the second day, coughing, often with (bloody) sputum, and chest pain occur. The patient has a rapid pulse and shortness of breath. Because of the strong coughing stimulus, those affected often vomit or have abdominal pain.
In about ten percent of all cases, the plague bacteria enter the blood and cause "blood poisoning". This so-called plague sepsis occurs as Complication of bubonic or pneumonic plague at. Possible symptoms include falling blood prere, high fever, confusion or lethargy, and digestive problems.
Since the pathogens can spread everywhere in the body via the blood, the consequences of plague sepsis are manifold and can affect various organs. Coagulation disorders are particularly dangerous, because they are associated with bleeding inside the body. Heart failure, enlargement of the spleen and liver, and kidney failure are other possible consequences.
If left untreated, plague sepsis leads to circulatory failure. If the blood flow in the body cannot be maintained, the patient dies of plague sepsis.
Plague: causes and risk factors
The reason why the plague was so widespread in the past was that people did not know what caused it and could not prevent it from spreading. It has only been known for a good 120 years that the plague is caused by a Bacterium (Yersinia pestis) is triggered. The pathogen is mainly found in rodents. Can be transmitted to humans by their fleas. Sick people can also pass the plague bacteria directly to other people. In the case of pneumonic plague, this occurs via droplet infection.
The plague bacterium is Highly contagious. In addition, it can be treated with a special mechanism trick the human immune system: Important defense cells of the immune system are certain white blood cells. They can "eat up" invaders like bacteria. Thus stop an infection. Not so in the case of the plague: The "eaten up" people Plague bacteria simply continue to divide inside the defense cells.
Where does the plague occur?
Nowadays the plague no longer exists in many countries. This is due to the fact that hygiene standards have improved dramatically in many places. Lack of hygiene, rats in the house and living in slums are possible risk factors for the development and spread of the plague. Today, plague still occurs in the following regions:
– Africa (especially Central, South and East Africa) – Asia (especially Russia, Middle East, China, Southeast Asia, Myanmar) – Central and South America (tropical and subtropical regions) – North America (southwestern USA)
Plague: examinations and diagnosis
If plague is suspected, the doctor will first discuss with the patient whose Take medical history (medical history). For example, it asks the following questions:
– What are the exact symptoms? – Since when do the symptoms exist? – Have you traveled recently? If yes, where? – Have had contact with rodents? – Have you noticed insect bites on you? – Are you a safety level S3 laboratory worker (these are laboratories that grow plague bacteria for sample evaluation)?
This is followed by Physical examination. Among other things, the doctor will palpate the lymph nodes, looking for swelling and pain. Sometimes the typical bumps of bubonic plague have already formed, which is a clear indication. In the case of pneumonic plague, the symptoms are often less clear-cut. Cough, bloody sputum and fever can easily be misinterpreted as severe pneumonia.
For a definite diagnosis, one must take the Plague bacteria can be detected in the body. For this purpose, the doctor pricks a swollen lymph node, takes a sample and sends it to the laboratory for analysis. If pneumonic plague is suspected, some sputum or a saliva sample is sent in. In the case of a plague infection, the bacteria causing the disease can be detected in these secretions or in the sample material from the swollen lymph nodes.
In addition to this direct detection of the pathogen, it is also possible to make a Blood test important. This test can be used to determine whether the bacterium is already in the blood (see also: plague sepsis) and whether the immune system has already recognized the pathogen.
Is the diagnosis "plague If the patient is not treated quickly, he is isolated so that he does not infect anyone else. His sickroom may only be entered under strict safety-. Protective measures must be taken. Any unnecessary contact with the patient is avoided.
Nowadays, the plague is referred to as Antibiotics treated, for example, with streptomycin, gentamycin, tetracyclines (z. B. doxycycline) or chloramphenicol. Doctors usually administer the drug first intravenously via syringe, later in tablet form.
After starting antibiotic therapy, patients with bubonic plague must remain isolated for at least two days, and patients with pneumonic plague for at least four days
Plague: course of the disease and prognosis
If bubonic plague is detected in time and treated consistently, the prognosis is good and almost all patients survive (mortality rate: 10 to 15 percent). Without treatment, however, 40 to 60 percent of patients die.
In cases of pneumonic plague and plague sepsis, the chances of survival are slim if patients are not treated quickly. However, if the doctor diagnoses the disease in time and starts antibiotic therapy, the mortality rate for these two forms of plague drops significantly.
Once a plague infection has been overcome, the patient is largely immune to a new infection. However, sometimes it can still come to a renewed disease.
The plague in the Middle Ages
Plague is one of the great infectious diseases of the Middle Ages. Colloquially it is also called Black death or Black plague called. The name comes from the fact that in the course of the disease, the skin can turn black and die off.
In the Middle Ages, major plague outbreaks ravaged Europe, claiming lives in the hundreds of millions of people. There is also evidence that the Black Death existed long before the Middle Ages. However, it is unclear whether this was really an infection with the bacterium Yersinia pestis.
Nowadays, scientists have gathered a lot of information about the plague in the Middle Ages. Thus, the outbreak and the spread of the disease at that time can be well understood. Strictly speaking, there were two major plague waves in Europe in the Middle Ages. In the 19. and 20. A worldwide pandemic followed in the sixteenth century, but Europe was largely spared. The spread as well as the distribution of the disease proceeded in each case on different ways. To this day, it is not clear why the further spread of plague in Europe did not progress for more than 700 years between the two major plague waves.
Plague pandemic 1 (ca. 541 to 750 n. Chr.): The first major wave of plague in the Middle Ages lasts from about 540 to 750 AD. It reached Europe from Egypt via the Mediterranean to present-day France. During this first major plague pandemic, about 100 million people died worldwide, including about half of the European population. There are many theories about the socio-economic as well as political consequences that caused this mass death in Europe. Some historians link it to Arab expansion toward southern Europe.
Plague pandemic 2 (14. to 19. Century): In the years 1340 to 1350 there was a big plague outbreak in Central Asia. Via the Silk Road trade route, the plague again reached Europe and Africa. The world population shrank during this time from about 450 million to 350 million people. Although the great wave of the plague ended only a few years after its onset in Asia. However, until the 19. In the twentieth century, small outbreaks occur again and again in Europe.
The black plague: change in medicine
The highly contagious infectious disease plague led to a fundamental rethinking in medicine. The foundations of our current understanding of diseases. Infection pathways were shaped by important discoveries during this period.
In the Middle Ages, for example, research on the dead was forbidden. However, due to the many deaths from the plague, this general ban was slowly lifted and the Dissection of cadavers acceptable. This upheaval represents an important moment in the medical understanding of the body.
The next big step was the realization that diseases can be contagious and transmitted through physical contact with sick people. However, it took another 200 years for this so-called contagion theory to become established.
Only with the third major plague in 18. and 19th century the transmission route of the plague was finally clarified. This was due to the fact that the ecclesiastical view (plague as punishment from God) of the population was no longer sufficient as an explanation alone. This set in motion the search for more mundane explanations. In 1894, the Swiss-French physician and bacteriologist Alexandre Yersin succeeded in identifying the Plague-to detect bacteria. In its honor, it was given its scientific name: Yersinia pestis.