Pulmonary anthrax
Introduction
Introduction to lung anthrax Pulmonary anthrax (pulmonaryanthrax) is an acute infectious disease caused by Bacillus anthracis. It is a native herbivore infectious disease. People are infected by contact with sick animals and their products or the meat of sick animals. The most common skin anthrax, manifested as skin necrosis and black sputum, can also cause lung anthrax caused by inhalation infection, can cause intestinal anthrax after eating infection, and can be secondary to anthrax septicemia. basic knowledge The proportion of illness: 0.003% Susceptible people: no special people Mode of infection: pathogen infection Complications: respiratory failure
Cause
Causes of pulmonary anthrax
Infection factors:
When the body's resistance is reduced, the pathogenic bacteria spread through the lymphatics or blood circulation, forming sepsis and secondary anthrax. The anthrax toxin damages the microvascular intima, which can cause diffuse hemorrhage, disseminated intravascular coagulation and septic shock. The host has a lack of immune response to the visceral anthrax infection, and the lesion progresses rapidly, often leading to death. The pulmonary anthrax is hemorrhagic lobular pneumonia, bronchial, mediastinal lymph nodes, hemorrhagic infiltration, pleural, pericardium often involved, necrosis Hemorrhagic mediastinal inflammation.
Bacillus anthracis is aerobic Bacillus, positive for Gram stain, has a capsule formation in humans and animals, has strong pathogenicity, grows well on general medium, general disinfectant, can be killed by heating at 75 ° C for several minutes. Extinguish, form spores in an aerobic environment in vitro, has strong resistance, can survive in the soil for a long time, boil for 30 to 50 minutes or strong oxidants (such as bleaching powder, potassium permanganate) can kill for 24 hours, sensitive to iodine .
Bacillus anthracis has 4 antigens:
1 capsular antigen: can resist the phagocytosis of phagocytic cells, and is related to pathogenicity;
2 bacterial antigen: a species specific, heat resistant;
3 protective protein antigen: is a component of anthrax toxin, has strong immunogenicity, and can produce immunity by injecting animals;
4 spore antigen: immunogenic and serological diagnostic value, anthrax toxin has three components, edema factor, lethal factor and protective antigen, no injection toxicity, mixed injection is lethal, capsule and toxin are anthrax The main cause of bacilli causing disease.
After invading the human body, Bacillus anthracis is multiplied locally by the protection of its capsule, producing a large amount of toxins, causing tissue edema, necrosis and hemorrhagic infiltration to form primary skin anthrax or pulmonary anthrax.
Prevention
Pulmonary anthrax prevention
1) Once you find a patient with suspected anthrax, be sure to report it to your local health center, hospital, or disease control center. Pulmonary anthrax is one of the Class A diseases managed by Class B infectious diseases and must be reported immediately after discovery.
2) Strictly manage the source of infection. Patients and sick animals should be treated in isolation, and their secretions and excretions should be disinfected. Prevent water pollution and strengthen supervision of diet and drinking water.
3) When investigating and treating patients with suspected pulmonary anthrax, wear protective clothing and wear a mask made of 16 layers of cotton gauze. At the same time, the patient should wear a protective mask. For close contacts, medical observation is required for 12 days. Check the body twice a day, measure body temperature and so on.
4) Strengthen labor protection. For the staff engaged in animal husbandry acquisition, processing, veterinary staff and people in the affected areas, non-toxic live vaccines can be used for vaccination, and an anthrax vaccine is given once a year. At present, the skin scratch method is used, and 0.1 ml of the vaccine is used each time, and the skin on the outer side of the upper arm is dropped, and a "well" word can be drawn. The fur purchase should be intensified, and the infected fur should be disinfected to kill germs and spores.
5) Strictly manage the source of infection. Patients and sick animals should be treated in isolation. The secretions and excretions should be disinfected. The body of the patient must be cremated. The body of the animal must be incinerated. The purchase of fur should be strengthened. The infected hair should be disinfected to kill the bacteria. And spores, strengthen labor protection, and inoculate non-toxic live vaccines for staff engaged in animal husbandry acquisition, processing, veterinary staff and people in infected areas. The protection period is about 1 year.
Complication
Pulmonary anthrax complications Complications, respiratory failure
If not rescued in time, it often occurs in acute symptoms 24 to 48 hours due to respiratory failure, circulatory failure and death.
Symptom
Pulmonary anthrax symptoms Common symptoms Septicemia, toxic, chills, high fever, convulsions, low fever, dry cough
The incubation period is generally 1 to 5 days, and the clinical manifestations are skin anthrax, pulmonary anthrax, intestinal anthrax, central nervous system anthrax and septic anthrax.
1. Skin anthrax: This type is most common, mostly occurs in the exposed parts of the face, neck, shoulders, hands, feet, etc., painful papules appear in the infected area, vesicles are formed, the surrounding tissues are hard and swollen, and the central area is 3 to 4 days. Hemorrhagic necrosis, surrounded by groups of vesicles, the edema area continues to expand, forming ulcers on the 5th to 7th day, bloody secretions formed into black cognac, becoming anthrax, 1 ~ 5cm, surrounding edema area 5 ~ 20cm, ranging, It is not painful and itchy, not purulent, may have local lymphadenopathy, fever, headache, general malaise, a few cases of local no black sputum formation and rapid development of malignant edema, systemic toxic symptoms.
2. Pneumoconiosis: mostly primary, but also secondary to skin anthrax, initially mild upper respiratory tract infection, low fever, dry cough, myalgia, a few days after the disease suddenly increased, manifested as high fever, chills, shortness of breath, asthma Nasal, cyanosis, hemoptysis, sweating and heart rate increase, neck, chest may have subcutaneous edema, lungs can smell and scattered fine wet voice and sputum pronunciation, can have a large number of pleural effusion, signs and severity Not proportional, X-ray in addition to showing pneumonia, pleural effusion, typical manifestations of mediastinal widening, patients with most critical illness, often complicated by sepsis and septic shock, can also be secondary to meningitis, manifested as severe headache, vomiting, convulsions, Coma, with obvious meningeal irritation, bloody cerebrospinal fluid can detect Bacillus anthracis.
Examine
Pulmonary anthrax examination
1. Peripheral blood: white blood cell count and neutrophil increase, may have leukemia-like reactions.
2. Pathogen examination: taking the patient's focal exudate, sputum, secretion, blood and cerebrospinal fluid for smear or culture, the pathogen can be found, can be used for capsular staining, specific fluorescent antibody staining for further identification, The above sample can be cultured or inoculated into the subcutaneous tissue of animals such as guinea pigs to isolate Bacillus anthracis.
3. Serology: The sensitivity and specificity of the traditional Ascoli precipitation assay are not high. The indirect immunofluorescence assay has high sensitivity and specificity.
X-ray performance in addition to showing pneumonia, pleural effusion, typically manifested as a mediastinum widening.
Diagnosis
Diagnosis and identification of pulmonary anthrax
According to the life history, occupational history and typical clinical manifestations of the sick animals and products, the diagnosis is generally not difficult. The diagnosis depends on the detection of the bacteria and the serological examination. The symptoms of lung anthrax are far greater than that of the leaf pneumonia. X Line checking helps to distinguish.
Must be differentiated from pneumonic plague.
