Yersinia pestis pneumonia
Introduction
Introduction to Yersinia pestis pneumonia Yersinia is now classified as Enterobacteriaceae, a pathogen of infectious diseases of the original animal, which is caused by contact with infected animals or contaminated food. The current Yersinia is divided into Yersiniapestis, Y. pseudotuberculosis, Y. enterocolitica and Yersinia (Y. Intermedia), the first three are highly pathogenic to humans. basic knowledge The proportion of illness: 0.0001%-0.0003% (this disease is more common in forest workers, the incidence rate is about 0.0001%-0.0003%) Susceptible people: no special people Mode of infection: digestive tract spread Complications: pleural effusion
Cause
Etiology of Yersinia pestis pneumonia
Bacterial infections:
After the bacteria enter the body, they can rapidly multiply and produce a polysaccharide capsule. The capsule can resist the phagocytosis and bactericidal action of non-sensitized nuclear cells. The pathogenic factors include endotoxin and other antigens. After entering the body, the bacteria are first localized. Localized skin in the lymph nodes or flea bites, causing hemorrhagic necrotizing lymphadenitis, which in turn causes sepsis. Secondary pneumonia is caused by septic bacteria involving the lungs, so it occurs in the lungs where the blood supply is good, and bacteria inhale through the respiratory tract. Can cause primary pneumonia.
Yersinia pestis, Enterobacter genus Yersinia, bipolar coloration, Gram-negative bacilli, no flagellum, no spores, capsule, facultative aerobic, good growth in blood agar or Maclonkey medium It produces typical rough colonies. There are many kinds of antigens in this strain. There are three kinds of F, T and V related to pathogenicity and immunogenicity. The Yersinia pestis can be divided into 5 groups (AE) 17 Ecotype, this strain is weak, especially sensitive to heat and dryness, sun exposure, roasting and common disinfectants can be killed, low temperature resistance, can survive for 10 to 20 days in pus, sputum body 1 Months, the body can survive for weeks to months.
Prevention
Yersinia pestis pneumonia prevention
1. Suspected patients should report the epidemic. The pneumonic plague must be strictly isolated from the respiratory tract to the sputum negative, and control the plague in rats. Visiting and patients are prohibited from communicating with each other. The patient's excrement should be thoroughly disinfected and the patient's death should be cremation or deep burial. The contact person should be quarantined for 9 days. For those who have received vaccination, the quarantine period should be extended to 12 days.
2. Eliminate the source of animal infection: monitor the epidemic situation of natural foci and control the plague in rats. Extensively launched the rodent patriotic health campaign. Drought and flood is an important source of infection in some areas and should be vigorously hunted.
3. Cut off the route of transmission: Eliminate the sputum to cut off the route of transmission, and spray on cats, dogs, livestock, etc.
4. The medical personnel entering the epidemic area, the resident of the epidemic area and the staff of the plague laboratory should be inoculated with the vaccine 2 weeks before, and the effective period is 1 year. Streptomycin 1 g intramuscularly, or sulfadiazine 4 g / d points, 4 times orally. The vaccination is usually EV non-toxic strain dry live vaccine, skin scratching method, that is, 2 drops of bacteria liquid, separated by 3-4cm. Immunization is available after 2 weeks.
Precautionary measures include burying dead animals, killing fleas in infected areas, reminding people not to enter infected areas, and confirming patients should immediately report to the health and epidemic prevention agencies with emergency epidemic situation, and should immediately isolate suspected patients and contact any patients who have contacted them. In particular, people who have face-to-face contact with patients with cough with this disease should be given prophylactic treatment, that is, oral administration of tetracycline, 2g per day, for 5 to 10 days, the patient should be isolated until the bacterial culture is negative, for the common bacteria Vaccination is effective and must be taken by the staff involved.
Complication
Yersinia pestis pneumonia complications Complications pleural effusion
Concurrent pleural effusion.
Symptom
Symptoms of Yersinia pestis pneumonia Common symptoms hemoptysis
Depending on the mode of transmission, after secondary pneumonia, there is usually no obvious skin lesions. Respiratory system usually occurs after fever for several days to one week. It is characterized by cough, shortness of breath, cyanosis, hemoptysis, chest pain, and lung. There is a little wet voice at the bottom, which can be complicated by pleural effusion. Primary aspiration pneumonia occurs after contact with plague pneumonia patients, and respiratory symptoms such as shortness of breath, cyanosis, weight loss, cough and white phlegm, and hemoptysis soon occur. Significant toxic symptoms and psychiatric symptoms can occur, and the deaths are highly contusive, so it is known as the "black death".
Examine
Examination of Yersinia pestis pneumonia
1. The white blood cells are generally (10 ~ 20) × 109 / L, obviously left shift, and even leukemia-like reactions.
2. Etiology examination can be found in the bipolar staining of Gram-negative bacilli, sputum, blood or lymph node aspirate culture can be positive, direct fluorescein-labeled antibody staining: this method is to detect the pathogenic bacteria antigen in the specimen, with Fast features can be used as a cause for diagnosis.
3. Hemagglutination test: serum antibody was detected by F1 antigen, and the serum antibody titer in the acute phase and the recovery phase was increased by 4 times, or the single serum titer exceeded 1:16, which was diagnostic.
4. X-ray showed basal nodular shadows of the lungs, flaky blurred infiltration shadows, enlarged hilar and mediastinal lymph nodes, occasionally pleural effusion, inhalation of primary pneumonia, visible in the onset within 24 hours of onset Shadows can further lead to ARDS or pulmonary edema-like changes.
Diagnosis
Diagnosis and identification of Yersinia pestis pneumonia
Depending on the patient's history of exposure and pulmonary involvement, the cause of the diagnosis depends on sputum, blood or lymph node aspiration Gram stain, culture, conditional units can be used for direct fluorescein-labeled antibody staining, can provide a rapid diagnosis of the cause.
In addition to the identification of T. serrata pneumonia and Pasteurella pneumonia, this disease should be differentiated from leptospirosis, anthrax and other serious lymphadenitis, pneumonia, and sepsis.
