Diagnosis of the plague

Diagnosis of the plague is based on clinical and epidemiological data: severe intoxication, the presence of ulcers, buboes, severe pneumonia, hemorrhagic septicemia in persons in the natural focal zone for plague, living in places where epizootics (drop) among rodents were observed or there is an indication of recorded cases of the disease. Every suspicious patient should be examined.

[1], [2], [3], [4], [5],

Indications for consultation of other specialists

Consultations are conducted, as a rule, to clarify the diagnosis. If a bubonic form is suspected, the surgeon's consultation is indicated, if there is a suspicion of a pulmonary form - a pulmonologist.

Specific and nonspecific laboratory diagnosis of plague

The blood picture is characterized by a significant leukocytosis, neutrophilia with a shift of the formula to the left and an increase in ESR. In the urine, a protein is found. With the X-ray examination of the chest organs, in addition to increasing the mediastinal lymph nodes, it is possible to see focal, lobular, less pseudoblacular pneumonia, with severe RDS. In the presence of meningeal signs (stiff neck muscles, positive Kernig symptom), a spinal puncture is necessary. In the spinal fluid, three-digit neutrophilic pleocytosis, a moderate increase in protein content and a decrease in glucose level are more often detected. Specific diagnosis of plague is based on the study of punctate bubo, separated ulcer, carbuncle, sputum, swab from the nasopharynx, blood, urine, bowel movements, cerebrospinal fluid, sectional material. Rules for the collection of material and its transportation are strictly regulated by the "International Health Regulations". The material is collected using special dishes, bixes, disinfectants. The staff works in anti-plague suits. Preliminary conclusion is given on the basis of microscopy of smears stained according to Gram. Methylene blue or treated with a specific luminescent serum. Detection of ovoid bipolar rods with intense staining at the poles (bipolar coloration) suggests a diagnosis of plague within an hour. For the final confirmation of the diagnosis, isolation and identification of the culture, sow the material on agar in a Petri dish or on a broth. After 12-14 hours there is a characteristic growth in the form of broken glass ("lace") on agar or "stalactite" in broth. The final identification of the culture is carried out on the 3-5th day.

The diagnosis can be confirmed by serological studies of paired sera in the RPHA, but this method is of secondary diagnostic importance. Pathologoanatomical changes are studied in infected mice, guinea pigs after 3-7 days, with sowing of biological material. Similar methods of laboratory isolation and identification of the pathogen are used to detect plague epizootics in nature. Materials for research are taken from rodents and their corpses, as well as fleas.

Example of the formulation of the diagnosis

A20.0. Plague, bubonic form. Complication: meningitis. Heavy current.

All patients with suspected plague are subject to emergency hospitalization on special transport to the infectious hospital, in a separate box with compliance with all anti-epidemic measures. Personnel caring for sick plague should wear a protective antiplague suit. Household items in the ward, allocation of the patient are subject to disinfection.

[6], [7], [8], [9], [10], [11], [12]

Differential diagnosis of plague

The list of nosologies with which differential diagnosis is necessary depends on the clinical form of the disease. Differential diagnosis of plague skin form should be carried out with a cutaneous form of anthrax, bubonic - from the cutaneous form of tularemia, acute purulent lymphadenitis, sodoku. Benign lymphoreticulosis, venereal granuloma; pulmonary form - from croupous pneumonia, pulmonary form of anthrax. The septic form of the plague must be distinguished from meningococcemia and other hemorrhagic septicemia. Especially difficult is the diagnosis of the first cases of the disease. Of great importance are epidemiological data: stay in the foci of infection, contact with rodents, patients with pneumonia. It should be borne in mind that the early use of antibiotics modifies the course of the disease. Even the pulmonary form of the plague in these cases can proceed benignly, but the patients still remain infectious. Given these features, if epidemics are present in all cases of diseases that occur with high fever, intoxication, skin, lymph node and lung lesions, plague should be excluded. In such situations it is necessary to conduct laboratory tests and involve specialists in anti-plague services.

Differential diagnosis of plague

Nosological form	General symptoms	Differential Criteria
Anthrax, cutaneous	Fever, intoxication, carbuncle. Lymphadenitis	Unlike the plague, fever and intoxication appear on the 2-3rd day of the disease, the carbuncle and the swelling zone around are painless, there is an eccentric growth of the ulcer
Tularemia, bubonic form	Fever intoxication, bubo. Hepatolienal syndrome	Unlike the plague, fever and intoxication are moderate, the bubo is not very painful, mobile, with clear contours; suppuration is possible on 3-4 weeks and later, after the temperature is normalized with a satisfactory state of the patient, there may be secondary buboes
Purulent lymphadenitis	Polyadenitis with local soreness. Fever, intoxication and suppuration	Unlike the plague, there is always a local purulent foci (panaritium, suppuration, wounds, thrombophlebitis). The appearance of local symptoms is preceded by fever, usually mild. Intoxication is poorly expressed. Periadenitis is absent. The skin above the lymph node is bright red. Its increase is moderate. Hepatolyenal syndrome is absent
Croupous pneumonia	Acute onset, fever, intoxication. Possible separation of sputum with a trace of blood Physical signs of pneumonia	In contrast to the plague, intoxication accrues to the 3-5th day of the disease. The phenomena of encephalopathy are not characteristic. The physical signs of pneumonia are pronounced clearly, sputum scanty, rusty, viscous

[13], [14], [15], [16], [17], [18], [19], [20],