Plague: Causes, Symptoms & Treatment

Although the plague no longer occurs in Germany today, it is still known by almost everyone through its history. Especially the plague epidemics of the Middle Ages have stuck in people’s minds. In some countries, however, there are still isolated cases of the subform pneumonic plague. Check with your doctor if you need more information.

What is plague?

Plague is a disease caused by the bacterium Yersinia pestis that occurs in four different manifestations: bubonic, pulmonary or abortive plague, and plague sepsis. Less commonly, plague meningitis occurs when the plague pathogens affect the meninges. Most people are familiar with plague as the Black Death of the Middle Ages – it is now considered largely certain that the historically documented plague waves were indeed attributable to the pathogen Yersinia pestis. However, most forms are treatable today.

Causes

The causative agent of plague is a zoonotic disease, a pathogen transmitted by animals. Rats are the best-known carriers, but squirrels, groundhogs, and similar rodents can also be dangerous. Yersinia pestis is not transmitted directly by the rodent itself, but by the bite of its fleas. Bubonic plague is usually caused by such a flea bite and develops a few hours to seven days later. It is accompanied by severe drowsiness, fever, and pus– or blue-colored swellings of the lymph nodes. This can result in plague sepsis, in which the bacteria enter the bloodstream, release toxins (poisons), die, and cause death there after no more than 36 hours due to internal and external bleeding. However, it can also lead to abortive plague due to the flea bite – only mild fever and feeling of illness occur, after which the patient is immune to all pathogens. Pneumonic plague, on the other hand, in which Yersinia pestis attacks the lungs, is still extremely dangerous today.

Symptoms, complaints, and signs

In approximately 90 percent of cases, the symptoms of bubonic plague appear during an infection with the plague pathogen. Thus, approximately two to six days after infection, the first symptoms appear. Those affected suffer from high fever, chills, headache, aching limbs and a very strong feeling of illness. The bumps (bubones) that give bubonic plague its name develop as a result of infected and inflamed lymph nodes. They swell severely and hurt. There is severe suppuration due to the infection, which eventually leads to the disintegration of the inflamed lymph nodes. These can also break open to the outside – through the skin. Further symptoms follow if the inflamed lymph vessels and nodes infect the blood circulation system. This can lead to sepsis. If Yersinia pestis reaches the lungs, pneumonic plague occurs with shortness of breath and bloody sputum. The symptoms of plague sepsis, on the other hand, can affect the entire body. There are infections of various organs, skin bleeding, digestive problems, enormous exhaustion and shock reactions. Plague sepsis is a symptom that can be expected in the course of an untreated plague infection. Plague sepsis is almost always fatal. Plague may also, in rare cases, present very mild symptoms that are hardly dangerous.

Diagnosis and course of the disease

Almost any form of plague begins with fever to chills, general ill feeling, and drowsiness. The incubation period ranges from a few hours to 7 days, and 1-3 days for pneumonic plague. To distinguish the form of plague, attention must be paid to the specific symptoms. In bubonic plague, for example, these are the swollen lymph nodes that turn purulent yellow to blue. Characteristic are shortness of breath, black-bloody sputum and pulmonary edema. Plague sepsis may result from both forms or may first bring on pneumonic plague, which is why it must also be recognized. It is manifested by an intensification of the general symptoms of the disease, and headache may be added. Only abortive plague is quite harmless: at best, it may resolve on its own after showing mild, nonspecific symptoms.

Complications

The extent to which the plague takes hold depends on the particular form. For example, symptoms are relatively mild in abortive plague. In other forms, however, there is a risk of serious complications. The risk is particularly high if there is no medical treatment for the plague.A complication that can arise from bubonic plague is pneumonic plague. In this case, physicians speak of secondary pneumonic plague, since the more common primary form is transmitted by droplet infection. Pneumonic plague takes a rapid course, sometimes showing up after only a few hours. However, secondary pneumonic plague progresses more slowly than the primary form. Typical signs include fatigue, chills, fever, headache, muscle aches, and dizziness. On the second day of the disease, coughing with black-blood sputum, chest pain, difficulty breathing, and a blue discoloration of the skin occur. Abdominal pain, diarrhea, nausea, and vomiting are also not uncommon. Pneumonic plague can develop into life-threatening plague sepsis, as can bubonic plague, skin plague, plague meningitis, or plague laryngitis. In about ten percent of all plague patients, the plague bacteria penetrate into the blood, where they cause blood poisoning. Plague sepsis is characterized by lethargy, high fever, digestive problems and a drop in blood pressure. In addition, the sick person reacts confused. Furthermore, plague sepsis can cause vascular occlusion, which affects the blood supply to the organs. In extreme cases, death of the patient occurs.

When should you go to the doctor?

Plague is one of the diseases that have not occurred in Germany for a long time. Nevertheless, a visit to the doctor is advisable if the affected person is convinced that he suffers from this deadly disease. Headaches and aching limbs, a very high body temperature and a feeling of illness are signs of an irregularity that should be investigated. If other flu-like symptoms occur, such as chills, fatigue and tiredness, a visit to the doctor is recommended. If there is discoloration of the skin, suppuration, as well as swelling of the lymph glands, action is needed. Sepsis may occur. This results in a life-threatening condition. Respiratory distress, bleeding of the skin and bloody sputum must be examined and treated as quickly as possible. If there is an increase in the existing symptoms, the affected person needs help immediately. In case of disturbances of consciousness or a state of shock, an ambulance service must be alerted. Since plague is a highly contagious disease, the instructions of the emergency physician should be followed. If left untreated, the disease can spread in a short time and infect countless people. In addition, there is a potential threat to the life of the infected person, since the course of the disease without medical care is fatal within a short time.

Treatment and therapy

The pathogen Yersinia pestis is a bacterium, so the basis of treatment for plague is antibiotics. The drug of choice is streptomycin, which is administered intramuscularly while the patient is subject to inpatient monitoring. Rapid treatment is especially important for pneumonic plague, which still has an extremely high mortality rate. If streptomycin cannot be used or if it must take effect very quickly in order to still help the patient, chloramphenicol is used, but it is considered a treatment of last resort. It is known for its strong side effect, aplastic anemia. Although this occurs in only one in 6000-36000 cases, it is a risk that should not be underestimated, especially in plague. Depending on the severity of the symptoms, these are also treated – high fever can be reduced, for example, and pain can be relieved with medication.

Aftercare

After contracting plague, patients are usually immune to reinfection. There is also no need for long-term treatment or daily support. The symptoms subside completely. The affected person returns to his or her everyday life. Aftercare measures mainly relate to the protection of other people. The easy transmissibility of the plague led to the death of entire regions in the Middle Ages. Patients with an established illness must remain in isolation for several days after the symptoms have ceased. A blood test provides information on whether the pathogen is still present in the organism. The best follow-up strategy is to avoid sick people and animals. Patients themselves are responsible for this. Anyone traveling to risk areas can be vaccinated against certain pathogens. However, the active substance only provides immunity for a short time.Unlike cancer, plague cannot arise from a new formation from the body itself. Isolation of sick people, as described above, is the most effective means of preventing infection. In the event of an outbreak of plague in Europe, government authorities provide quarantine. Patients must follow the instructions of medical personnel without fail.

Outlook and prognosis

Unlike earlier times such as the Middle Ages, when plague depopulated entire regions, the prognosis for the infectious disease is more favorable in the present. However, even today, the outlook depends on the form of progression and whether it is treated in time. For example, if the plague is abortive, it is a mild form of plague with a positive prognosis. Thus, antibodies are produced by the organism’s defense system, which provide immunity that lasts for a long time. If the patient suffers from bubonic plague and it is treated at the right time, the chances of recovery are good and the affected persons survive the severe disease. However, if timely treatment with antibiotic drugs is not carried out, between 50 and 60 percent of those suffering from the disease die. Thus, the drugs must be administered after about 15 hours at the latest. The prognosis is considered particularly unfavorable when plague forms such as pneumonic plague or plague sepsis are present. Thus, patients often do not receive rescue therapy in time. However, if the diagnosis is made early and the plague is treated with antibiotics, the mortality rate for both pneumonic plague and plague sepsis is reduced by about 15 percent. Normally, the affected person has extensive immunity to plague if he or she survives the disease. However, in some patients, plague outbreaks show up again later.

Here’s what you can do yourself

Plague is considered an eradicated disease in Germany. Due to changes in hygienic conditions over the last hundred years, as well as medical advances, the plague is known to current generations only through historical lore. Nevertheless, caution should always be exercised when handling wild animals. Direct skin contact with squirrels or rodents of any kind should always be avoided in the wild. Rats in particular can transmit the disease-causing bacteria. Since plague is a life-threatening disease, a doctor should be consulted at the first signs and symptoms. Self-directed treatment or taking self-determined measures to alleviate symptoms, is not advised. The attending physicians should be fully informed about the cause and course of transmission. Plague is a notifiable disease that is treated by medical specialists. In the very unlikely event of contracting the disease, the doctor’s instructions should always be followed so that one’s health can quickly improve and no further complications arise. Since the risk of infection is very high, handling and physical contact with other people should be avoided. The patient will be placed in a quarantine ward to prevent the pathogen from spreading further into the population.