Plague

The fever is an acute disease caused by a bacterium called Yersinia pestis.

It mainly affects wild rodents and their ectoparasites. Sometimes, when a human being comes into contact with these animals, they can become infected with this disease. The great historical epidemics in cities occurred when the disease was transmitted to man by rats.

Plague is produced after the bite of rodent fleas. It causes a painful local adenopathy, called bubo. Subsequently, sepsis occurs with spread to other organs and death occurs if there is no correct and immediate treatment.

Currently the plague is located in areas of the southwestern United States, southwestern Russia, India, Indochina and South Africa. In addition to rats, other animals can carry the bacteria after contact with infected rats, such as wild dogs, foxes, and coyotes; therefore this can be another way of contact of man with the disease.

Outbreaks of the disease in cities are currently rare. However, the transit of travelers from one area to another can serve as a vector for the transmission of the disease when one of these areas is endemic to plague.

Causes of fish

Yersinia pestis is an aerobic bacterium. It produces a series of virulent substances that make the disease acute and fatal.

It is a very resistant microorganism to desiccation and extreme temperatures, so it is able to survive in the burrows of rodents during the hibernation season.

The rodent infected by the bacteria acts as a reservoir. When man comes into contact with it, the flea can bite and infect him.

Once the bacteria are inside the human body, they migrate to the lymph nodes, where they multiply and make toxins. After 2-6 days, an inflammation of the ganglion occurs and these undergo necrosis that allows the bacteria to reach the bloodstream. From the blood it can reach some organs, including the lung, and progressive pneumonia with pleural exudate can occur. Later lung lesions may solidify, resulting in respiratory distress or an elevation in lung pressure. If the disease progresses without treatment, meningitis can occur .

Petechiae and hemorrhages appear on the skin. Belatedly, buboes can be infected by other bacteria.

The production of toxins by the bacteria can lead to death from toxic shock and a serious illness called DIC.

Plague symptoms

Bubonic plague has an incubation period of 2-7 days. It is common to find a small lesion at the site of the bite.

The patient presents painful buboes in any of the lymph nodes of the body. Headache , anorexia, nausea, vomiting and diarrhea (sometimes with blood) appear as typical symptoms . Up to 50% of patients have petechiae and skin hemorrhages.

Subclinical DIC can appear in up to 85% of patients, and in 5-10% of these it manifests with gangrene of the fingers and toes.

After the lymph nodes, the most frequently affected organ is the lung, resulting in secondary pneumonia. Cough, fever and tachypnea appear. Subsequently, severe dyspnea, hemorrhagic sputum, and respiratory failure appear.

Plague meningitis is a late complication seen in approximately 6% of untreated patients, characterized by a stiff neck, headache, mental confusion, and coma.

How is it diagnosed?

Bubonic plague should be suspected in a febrile patient with painful adenopathy and a history of exposure to a wild animal in an endemic area of ​​the disease.

It can be confused with many other diseases, so the CULTURE of the bacteria in the aspirate of the bubo must be carried out to confirm the diagnosis.

Depending on the symptoms that the patient presents, one test or another will be performed:

If there are pulmonary symptoms, a chest X-ray to rule out pneumonia.

If the symptoms are neurological, a lumbar puncture and a culture of the cerebrospinal fluid will be performed.

Plague treatment

If plague is suspected, treatment should be started immediately.

Effective antibiotics are streptomycin, tetracycline, and chloramphenicol. If there is meningitis, treatment is done with chloramphenicol. Tetracycline or cotrimoxazole should be given as prophylaxis in contacts.

The local treatment of buboes is not indicated, except those that open, to avoid infections by other bacteria.

In patients with respiratory dysfunction syndrome or severe pneumonia, assisted ventilation may be indicated.

There is a vaccine against the disease.

How can I avoid it?

Those who work with animals in endemic areas or with the bacteria or possibly infected samples in the laboratory, should consider using the vaccine to prevent contact. Because immunity is not persistent, it must be repeated at 6 months.

For those who go to endemic places of the disease, there is the possibility of using prophylaxis with tetracycline or cotrimoxazole.

Patients with pneumonic plague should be placed in respiratory isolation. If there is no respiratory involvement, hand washing is sufficient.

Community hygiene measures (rodent control and surveillance of wild animals) condition the prevention of epidemics. The extermination of rodents must be accompanied by flea control measures, to prevent the shortage of rodents from causing the bite to man to feed.

In our geographical area the presence of this disease is very rare. If you have been in endemic areas of the plague and have had contact with sick people, you should go to the doctor to follow a preventive guideline.

Any deep skin lesion or swollen lymph nodes, accompanied by fever or not, is a reason to see your GP. After conducting an interview, he will be the one who determines the need for complementary tests or the establishment of a treatment.