Bubonic plague is a quarantine natural focal infection. The main clinical symptom is the presence of plague bubo. Nosology is characterized by high fever, severe intoxication, with immunosuppression, visceral lesion, generalization of infection is possible. Diagnostics is based on the detection of the pathogen in biological materials (microscopy, seeding, PCR), serological methods are uninformative, practically not used. Treatment is carried out under mandatory quarantine, includes antimicrobial etiotropic therapy, massive detoxification, symptomatic methods. Less often they resort to surgical interventions.
A20.0 Bubonic plague
Bubonic plague refers to vector-borne diseases. The first written mention of the symptoms of this infection is found in the tales of Gilgamesh, the Old Testament of the Bible. However, the plague bacillus was discovered only in 1894 – simultaneously by Japanese (Shibasaburo) and French (Jensen) scientists. The plague is widespread everywhere, the most dangerous zones are the USA, China, Brazil, Peru, Vietnam, Mongolia and a number of other countries. A high incidence was registered in Altai, the Caucasus, and Stavropol. Bubonic plague seasonality – summer and autumn months; the stages of the epidemic process in nature are characteristic. Men are more likely to suffer from this form of the disease.
The causative agent of the disease is the bacterium Yersinia pestis. The source and reservoir of infection are sick people, rodents, hares, foxes, camels, domestic cats and other animals. The carriers are fleas, in whose digestive tract plague bacilli multiply. Insects become contagious already 3-5 days after the pathogen enters them and remain so for a year. When a flea bites, it regurgitates the contents of the stomach with a large number of bacteria inside the wound. Airborne, fecal-oral and contact-household ways of infection are also described.
The main risk factors for infection with bubonic plague are considered to be living and performing military service in endemic territories, professions related to the extermination of rodents, work in granaries, veterinary service. Archaeological expeditions that uncover ancient burial sites, as well as animal breeders, medical personnel, shepherds, tourists, employees of international airports, zoos are at risk. Bubonic plague is most susceptible to children, persons under the age of 20, and adult men.
After penetration into the body, plague bacteria multiply at the site of introduction, forming an inflammatory compacted area or a papule, a pustule with hemorrhagic contents. The spread of the pathogen occurs lymphogenically to the regional lymph nodes, inside which the bacteria multiply. The peculiarity of Y. pestis is the ability to suppress the phagocytic activity of macrophages, intracellular reproduction in them. At the same time, a large number of toxins, tissue breakdown products, pathogens are released, which causes intoxication symptoms.
The dense fibrous nodular membrane prevents polymorphonuclear leukocytes and specific antibodies from entering the inflammatory focus. Active replication of the pathogen contributes to the melting and enlargement of the lymphatic tissue of the regional nodes, resulting in conglomerates. Prolonged persistence, massive inflammatory process leads to hemorrhagic necrosis of the nodular tissue and the release of plague bacillus into the systemic circulation, followed by generalization of infection; in 10-20% of cases, symptoms of secondary pulmonary plague develop.
Bubonic plague symptoms
The incubation period is 2-6 days, less often 1-12 days, the leading symptoms are increasing local pain (usually in the groin), fever up to 39-40 ° C or more. Patients are forced to maintain extremely uncomfortable postures to reduce pain. Severe chills, pronounced weakness, headaches, sleep disorders, anxiety, discoordination of movements, sometimes delirium, hallucinations are characteristic. About half of those with bubonic plague report symptoms of gastrointestinal disorders: abdominal pain, nausea, vomiting, episodes of diarrhea.
After 1-3 days without treatment, mainly in the groin area, less often in the area of the armpits or neck, a very dense, sharply painful formation with hyperemic, hot, sometimes glossy skin above it is found. The conglomerate is immobile because it is soldered to the surrounding fiber. Movements in the limb (more often – the lower one) are limited. After a few days, the formation softens, pulsating pains appear in it, a fistula hole may form with an outpouring of purulent contents. After opening the bubo, patients note some improvement in well-being, a decrease in the severity of symptoms.
The most frequent negative consequences of bubonic plague include symptoms from the blood clotting system (up to 86% of patients), which in 5-10% of cases leads to dry gangrene of the skin, upper and lower extremities. 5-50% of patients have complications in the form of single, multiple, or massive hemorrhages. In patients with bubonic plague with impaired immunity, severe concomitant systemic diseases, a transition to a generalized form occurs on the 2-3 day of the disease.
The standards for the diagnosis of bubonic plague provide for the consultation of an infectious disease specialist, other doctors are involved for examination and treatment according to indications. An important element of the diagnostic search is the collection of an epidemiological history, strict compliance with the rules of inspection, taking, transportation and research of biological substances; work with them is allowed only in the conditions of quarantine infection laboratories. The most informative instrumental and laboratory studies in bubonic plague are considered to be:
- Physical data. Objectively, the symptoms of intoxication involvement of the central nervous system are determined: patients are excited, restless, slurred speech. Palpation bubo is a sharply painful sedentary conglomerate of lymph nodes with indistinct contours, hyperemic hot skin above it, fluctuation or fistulas; plague flictenes occur near the formation. The patient’s forced posture is noted. Pathological changes on the part of internal organs are usually absent.
- Laboratory tests. The general clinical blood test is characterized by pronounced leukocytosis, a shift of the leukocyte formula to the left, neutrophilosis, increasing thrombocytopenia, secondary anemia, acceleration of ESR. Changes in biochemical parameters are transient, more often there is an increase in the activity of ALT, AST, total bilirubin, urea, creatinine, hypoproteinemia. In the general analysis of urine, erythrocyturia is detected.
- Identification of infectious agents. After 1-2 hours, the laboratory must provide the results of microscopy of the fistula discharge or bubonic punctate; PCR is allowed. It is mandatory to sow biological materials on nutrient media. Serological techniques (ELISA, RPGA) can be evaluated only from the 2nd week of infection by examining paired serums at intervals of 14 days to fix the growth of the antibody titer at least four times.
- Instrumental techniques. Chest radiography is mandatory to exclude radiological symptoms of plague pneumonia; CT and MRI are less often indicated. For the purpose of differential diagnosis with malignant neoplasms, ultrasound examination of the mammary glands, pelvis, abdominal organs, soft tissues, retroperitoneal space, lymph nodes is recommended; bubonic puncture is possible under the control of ultrasound.
Differential diagnosis is carried out with tularemia (a slightly painful bubo that is not soldered to the skin). With tuberculosis, the growth of the lymph node is gradual, there are indications of immunodeficiency, symptoms of tuberculosis in the anamnesis. Rat bite, spotted-urticaria rash or cat scratching, lymphangitis indicate in favor of sodoku and cat scratch disease, respectively. Lymphogranulomatosis manifests symptoms of lung, bone, and gastrointestinal tract damage. Chlamydia infection sometimes occurs with inguinal unilateral lymphadenitis, soldering with surrounding tissues, formation of fistulas.
Bubonic plague treatment
All patients with suspected disease or with pathognomonic symptoms must be hospitalized in the boxed ward of the infectious diseases department for the immediate start of treatment. Bed rest is prescribed up to 4-5 days of normalization of body temperature, movement is limited to boxing. Dietary recommendations are non-specific, due to the need for the introduction of antibiotics with a wide range of undesirable toxic phenomena, therefore, heavy food and alcohol are excluded from the patient’s diet. The drinking regime is increased for the purpose of detoxification.
Treatment of patients with bubonic plague is aimed at reducing the severity of symptoms, preventing infection of other people. Patients must be prescribed antibacterial agents that are effective against the pathogen and administered parenterally. These include streptomycin, tetracyclines, fluoroquinolones, aminoglycosides, cephalosporins, rifampicin. Massive intravenous detoxification with glucose-salt, succinate-containing solutions, the appointment of painkillers, anti-inflammatory, antipyretic agents is required. The scope of symptomatic treatment depends on the clinical need.
Local treatment of bubones outside of their softening is not carried out. For therapeutic and diagnostic purposes, a fine needle puncture biopsy of the lymph nodes can be performed with simultaneous emptying of the bubon. In the presence of a skin ulcer, its excision is performed for the purpose of histological examination. Surgical autopsy and drainage of bubons is recommended when a symptom of conglomerate fluctuation appears, while antibiotics active against Y. Pestis, streptococci and staphylococci are administered intra-bubonically.
In the course of modern research, it has been established that macrophages carry a receptor for corticosteroids, which contributes to the potentiation of the action of their own immune system in the symptoms of bubonic plague. In experiments with the treatment of mice, an increase in the macrophage ability to infiltrate infected tissues and absorb apoptotic neutrophils under the action of these hormonal drugs was proved. There was also an increase in bacterial uptake and an improvement in the survival of infected animals.
Prognosis and prevention
The prognosis in the absence of treatment is serious, mortality reaches 7-26%. The most unfavorable localizations are considered axillary (15-20%) and cervical (5%) zones due to the risk of developing symptoms of the pulmonary form of the disease and edema of the airways. The total duration of inpatient treatment for patients suffering from bubonic plague should be at least 4 weeks, medical supervision after discharge – at least 3 months. The term of isolation of contact persons is 7 days.
Specific prevention is indicated for people living in endemic regions, tourists, military. Vaccination is carried out with a dry live vaccine. Non-specific measures include strict sanitary control over water supply and sanitation systems, planned deratization in sewers, supervision of migrants, tourists, imported products, animals. Important measures to combat the spread of the plague are early isolation and treatment of patients, quarantine of contact persons, disinfection in the hearth, improvement of sanitary and hygienic living conditions.