Pneumonic plague

Introduction to pneumonic plague Plague is a natural epidemic disease caused by Yersinia pestis. Under certain conditions, it is transmitted to humans through epidemic rats and epidemic plagues. The disease is acute, the disease is serious, and the infection is strong. The mortality rate is high, and acute lymphadenitis is the most common clinical, followed by sepsis, pneumonia, meningitis and skin plague. basic knowledge The proportion of illness: 0.0008% Susceptible people: no special people Mode of transmission: insect vector transmission Complications: sepsis septic shock respiratory failure

Cause of pneumonic plague

Cause of the disease (45%):

Yersinia belonging to the genus Enterobacteriaceae of the genus Yersinia, a Gram-negative bacillus, no flagellum, no spores, a capsule, facultative aerobic, plague bacteria containing a variety of antigens, related to pathogenicity and immunity There are three types of F1, T, V:

1. The capsular antigen of the F1 antigen pathogen is a glycoprotein which is highly specific and has been widely used for diagnosis such as serum.

2. The murine toxin in the T antigen is only toxic to the mouse, and the lipopolysaccharide endotoxin in the cell wall can cause human body heat, disseminated intravascular coagulation, complement activation and tissue lesions.

3. V and W antigens are mediated by plasmids and are only present in virulence strains, and the protective bacteria can multiply in mononuclear macrophages.

Yersinia pestis is weak against the outside world, especially sensitive to heat and dryness. It can be killed by sun exposure and common disinfectants, cold tolerance, and can survive for more than 1 year in pus, sputum and soil.

Pathogenesis (25%):

The plague bacillus invades the human body from the skin, through the lymphatic vessels to the lymph nodes, causing primary hemorrhagic necrotizing lymphadenitis. The release of toxins from the pathogen can cause symptoms of systemic toxic blood. The bacteria can enter the blood circulation and cause massive sepsis to cause sepsis. There may be septic shock, disseminated intravascular coagulation, and the invasion of the bacteria from the respiratory tract causes primary pneumonic plague, hemorrhagic bronchitis and necrotizing pneumonia, hemorrhagic necrotic hilar lymphadenitis and fibrinous hemorrhagic pleurisy.

Pneumonic plague prevention

Suspected patients should report the epidemic situation. The pneumonic plague must be strictly separated from the respiratory tract to the sputum negative, control the plague between rats, eliminate cockroaches to cut off the transmission route, strengthen personal protection, and the residents of the infected area and plague laboratory staff should be vaccinated 2 weeks ago. Vaccine, valid for 1 year, can be prevented by drugs, 1g intramuscular injection of streptomycin, or 4g/d of sulfadiazine, 4 times orally.

Pneumonic plague complications Complications sepsis septic shock respiratory failure

Concurrent sepsis and septic shock, severe cases of respiratory failure.

Pneumonic plague symptoms Common symptoms Difficulty breathing, hepatosplenomegaly, hyperthermia, chills, respiratory failure, diarrhea

symptom

The incubation period is short, usually 3 to 5 days, the primary pneumonic plague is several hours to 3 days, the onset is acute, high fever with chills, chills, systemic toxin symptoms, swollen lymph nodes, vomiting, diarrhea, hepatosplenomegaly and Bleeding performance, pulmonary plague is caused by spread of bubonic plague blood, a few are primary inhaled pulmonary plague, cough is pus and blood stasis, chest pain, hemoptysis, difficulty breathing, cyanosis, less lung signs, a small amount of wet snoring And pleural friction sounds.

Sign

The severity of the disease is inconsistent with the severity of the disease. If the rescue is not timely, there may be disturbances of consciousness, and more deaths from shock and respiratory failure. The skin of the whole body is dark purple after the death of the disease, so it is called "black disease."

Pneumonic plague examination

1. Peripheral blood: white blood cell count and neutrophils are significantly elevated, and even leukemia-like reactions, mild to moderate anemia with thrombocytopenia.

2. Bacteriological examination : bacteriological examination is the basis for the diagnosis of this disease, lymph node puncture, sputum, blood or cerebrospinal fluid, tableting or printing staining microscopy, culture and animal inoculation.

3. Serological examination: The agglutination test of plague is a commonly used diagnostic method. The reverse hemagglutination test detects the antibody titer of the antibody in the acute phase and the recovery phase by more than 4 times, or the titer 1:100 has diagnostic value.

4, X-ray chest X-ray: manifested as bronchial pneumonia or fusion solid shadow.

Diagnosis of pneumonic plague

diagnosis

According to epidemiological data, clinical fever, systemic toxic symptoms, acute lymphadenitis or cough, chest pain, hemoptysis, dyspnea, etc. should be suspected of plague, determined by pathogen detection of plague and/or detection Serum-specific F1 antibody, titer 1:100 or double serum antibody titer increased more than 4 times.

Differential diagnosis

Pneumonic plague must be differentiated from other lung inflammations, such as lobar pneumonia, pulmonary anthrax, leptospirosis, and mycoplasmal pneumonia.

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