Melioid
Introduction
Introduction to snot Melioidosis is an endemic infection caused by Burkholderia pseudomallei, which is prevalent in tropical regions such as Southeast Asia and northern Australia. People are mainly infected by contact with water and soil containing pathogenic bacteria and damaged skin. The clinical manifestations of this disease are complicated. Patients with acute sepsis often have multiple suppurative lesions. Chronic patients have similar manifestations of cavitary pulmonary tuberculosis. More serious, if not treated in time, the mortality rate is very high. basic knowledge The proportion of illness: 0.003% Susceptible people: no specific population Mode of transmission: contact transmission, insect vector transmission, digestive tract transmission Complications: lung abscess pericardial effusion osteomyelitis spleen abscess liver abscess prostatitis sepsis
Cause
Cause of snoring
Rhizoctonia pyogenes is a parasitic fungus that is Gram-negative bacilli, aerobic growth, and resistant to various factors in the natural environment. It is found in soil and surface water, and people are exposed to contaminated soil or water. Direct contact, respiratory tract, digestive tract and blood-sucking insect bites and other infections, no mutual infection between people.
Causes:
The pathogen of this disease is Burkholderia pseudomallei. This strain was first identified in Yangon by Whitmori and Krishnaswami in 1912. Because of its morphology and culture characteristics, it is similar to the sputum bacillus, and there is a clear crossover in serology. At that time, it was named Pseudomonas psedomallei. In 1921, it was renamed as Whitmore's baciilus. It was renamed in 1957 and renamed Pseudomonas sinensis. In 1993, it was internationally based on its new The biological characteristics found, named as Burkholderia typhimurium, due to the widespread use of sputum-like bacilli in the country, so this section still uses this abbreviation, Rhizoctonia pyogenes is short and straight medium gram-negative cocci, long 1 ~ 2m, width 0.5 ~ 0.8m, more than one, even pairs or clusters, no capsules and spores, more than three flagella at one end, so the movement is lively, common staining common two-pole thick dye, the pressure prepared by infecting organ samples When the print is dyed, there is a white circle around the cells, which is called a pseudo-capsule. The bacteria are aerobic bacteria and can grow well on ordinary medium. Into growth, cultured on 4% glycerol nutrient agar for 24h, forming a perfect circle, the central micro-uplift, showing smooth colonies, becoming rough after 48-72h, honeycomb folds on the surface, and concentric, culture The substance has a strong mildew smell, and the biochemical reaction characteristics of the bacteria are active, which can decompose glucose, lactose, maltose, mannitol, L-ribose and sucrose, etc., acid production does not produce gas, but does not decompose L-xylose, and it is nasal Identification of K. cholerae.
The strain contains two main antigens, one is a specific heat-resistant polysaccharide antigen, and the other is a heat-resistant protein common antigen similar to B. sinensis; followed by a flagellum antigen, according to the presence or absence of heat-resistant antigen, It can be divided into two serotypes: type I bacteria have heat-resistant and heat-labile antigens, mainly distributed in Asia, type II bacteria only have heat-resistant antigens, mainly distributed in Australia and Africa, and Rhizoctonia pyogenes in the external environment. Strong resistance, 27 days in the feces, 17 days in the urine, 8 days in the dead body, can survive for more than 1 year in water and soil, and 28 to 44 days in tap water, according to Guangzhou Observing that the bacteria survived in 726 days in soil containing about 40% water, heated at 56 ° C, 10 minutes to kill it, the common concentration of various disinfectants quickly kill the bacteria, but the sterilization of phenol and cresol soap solution The effect is not satisfactory. 5% chloramines-T is generally used as a conventional disinfectant.
Prevention
Bootropia prevention
There are currently no vaccines available. For areas where nasal snoring may occur, such as Guangdong, Guangxi, Hainan, etc., a certain number of stagnant water samples can be taken, soil samples and suspected pigs, cattle and sheep are tested for serum and bacteriology. To find out the distribution of the source of the epidemic, and carry out terminal disinfection after the typhoon and heavy rain in the suspected epidemic area, quarantine the pigs and sheep in the epidemic area, and prevent the infected animals from being transported to non-endemic areas, causing the spread of infection, on pigs and cattle. The mutton test should also be included in the sputum-like quarantine project. The suspected dust in the infected area, the local work or life of the sewage should pay attention to personal protection, mainly to prevent the water and soil of the contaminated sputum bacillus through the skin, mucosal infection, the excrement of patients and sick animals. And purulent exudate should be thoroughly disinfected. Personal contact should be paid attention to when contacting patients and sick animals. Skin disinfection should be carried out after contact. Medical investigation should be carried out for suspected infected persons for 2 weeks. Animals imported from the source should be strictly The epidemic and allergic examination can be applied to the important measures for the quarantine of equine animals, that is, the crude nasosin is purified by affinity chromatography, and the animals are spotted. Those with purulent eyelids were judged as positive.
Complication
Bowel-like complications Complications Pulmonary abscess pericardial effusion osteomyelitis spleen abscess liver abscess prostatitis sepsis
Subacute type often has lung abscess, empyema and lung inflammation, followed by pericardial effusion, osteomyelitis, spleen abscess, liver abscess, prostatitis and subcutaneous or soft tissue abscess, etc., multiple chronic abscesses can also occur, such as subcutaneous, Joints, bones, heart, brain, abdominal viscera, prostate and other purulent infections, occasionally sepsis and early death.
Symptom
Symptoms of the nose, common symptoms, abdominal pain, weight loss, chest pain, high fever, diarrhea, abscess, hepatosplenomegaly, empyema, pustular muscle pain
The incubation period of the disease is generally 3 to 5 days, but it is also several months after infection, several years, and even after 20 years of onset, the so-called "latent type of nasal discharge", such cases are often induced by trauma or other diseases, clinical There may be acute septic type, subacute type, chronic type and subclinical type.
1. Acute septic type is the most serious type, accounting for about 60%, the onset is more urgent, chills and fever, and there are shortness of breath, muscle pain, etc., as well as symptoms and signs of lung, liver, spleen and lymph node inflammation and abscess formation, especially Lung abscess is most common, occurs in the upper lobe of the lung and can involve the pleura. At this time, the patient has cough, chest pain, hemoptysis and purulent sputum, chest can smell dry, wet voice and pleural friction sound, and lung Consolidation and signs of pleural effusion (purulent chest), lung lesions merge into a cavity, others have abdominal pain, diarrhea, jaundice, hepatosplenomegaly and skin pustules, when bacteremia only affects a single organ, Non-dispersive septic infection can occur, usually without shock.
2. The subacute type of disease lasts for several weeks to several months, and most of the symptoms and signs of multiple suppurative lesions are formed after the acute infection subsides.
3. Chronic type of disease for several years, often due to the collapse of the abscess caused by fistula, long-term unhealed, typical cases of the upper lobe cavity lesions (pulmonary suppuration), often misdiagnosed as tuberculosis, has been reported A patient with a bone sinus abscess has a course of up to 18 years. In this long course, this type of patient often has intermittent fever, cough, hemoptysis or purulent sputum, gradual weight loss, malnutrition and exhaustion.
4. There are a considerable number of people in the subclinical endemic area. The clinical symptoms are not obvious after infection with Rhizoctonia sinensis, and specific antibodies can be detected in serum. This phenomenon is similar in the population of Southeast Asian countries (Thailand, Vietnam, Malaysia). 6% to 8%, subclinical patients generally do not develop dominant nasal sputum, but when there are incentives such as diabetes, there is still a chance to occur, it is reported that in the 1960s, 9% of the US military in the Vietnam War Subclinical cases have occurred after returning to China. The longest incubation period is 26 years, so it is called "Vietnamese time bomb".
The distribution of this disease has strict regional characteristics. Most patients have a history of exposure and infection. For any unexplained suppurative disease (especially cavitary lung disease) or febrile illness, the possibility of having a type of nasal discharge should be considered. Pseudomonas sinensis culture (the bacteria can grow in most laboratory media, 48 to 72 hours can be the result) and the blood coagulation test of the paired serum, agglutination test and complement fixation test are helpful for diagnosis.
Examine
Snoring
When it is suspected that the disease may be caused, indirect hemagglutination, complement fixation, radioimmunoassay and other serological tests must be performed. The final diagnosis also requires bacteriological separation or PCR (polymerase chain reaction) detection.
1. Most of the blood is anemia, the total number of white blood cells increases in the acute phase, and the increase in neutrophils is dominant.
2. Pathogen examination Take the patient's blood, sputum, cerebrospinal fluid, urine, feces, local lesions and purulent exudate for bacterial culture or animal inoculation to isolate Rhizopus oryzae. Uncontaminated clinical specimens can be directly inoculated into nutrient agar or Nutritional broth, cultured at 37 ° C for 24 to 48 hours, can obtain positive results of pure culture, blood culture in the absence of antibiotics, the ratio of blood to medium is 1:4; if the application of antibacterial drugs is 1:10 The contaminated specimens should be replaced with a selection medium. On the basis of the commonly used MacKakkai culture medium, 2 mg of polymyxin is added per 10 ml, and the suspected lawns obtained by the cultivation are diluted with physiological saline to form 5000/ml bacteria. 0.5m1 bacterial injection into the human abdominal male hamster (or 200-250g guinea pig) abdominal cavity, after the animal died, cross-sectional view, such as testicular redness, suppuration, ulceration, scrotal puncture with white in the casein-like exudate, that is Straus was positive, and if necessary, bacterial culture was separated from exudate or pus, which was further confirmed.
3. Serological examination has great value for the diagnosis of this disease. The following four methods are commonly used.
(1) Indirect hemagglutination test: at home and abroad, the titer of 1:40 or above is the critical value for diagnosis. However, due to the high background of the infected area and the late appearance of hemagglutination antibodies, the clinical applicability is poor. As an epidemiological investigation application, the exotoxin of Rhizoctonia solani has recently been linked to cells, and its exotoxin antibody has been tested as a marker of current infection, which has improved the clinical value of this test.
(2) Complement binding test: It is diagnostic value if the titer is required to be above 1:8. Although the complement antibody appears earlier and can be maintained for more than 2 years, its sensitivity is better than the hemagglutination test, but the specificity is poor. The cross-reaction is high and the practical value is not great.
(3) Enzyme-linked immunosorbent assay: Dharakul has been improved in coating antigens, using DNA fragments with molecular weights of 30×103, 19×103, for purification of antigens and anti-antigens such as IgG and IgM, and its diagnostic efficiency. For less than 85%, the rate of misdiagnosis and missed diagnosis are both 15%. Domestic Chen Guangyuan has improved this. Using 2000bp specific antigen as the indirect ELISA coating antigen, the diagnostic efficiency is improved to 98%, and the rate of missed diagnosis is At 3.9%, the misdiagnosis rate was only 1%, and it was considered that the previous 2 times antibody was more than 4 times higher than the current infection, and the decline was the previous infection.
(4) PCR technology: using a 22bp oligonucleotide primer to amplify a 178 bp DNA product, which can detect the level of 10 bacteria in 1 ml of whole blood, and other methods such as agar immunodiffusion test and fluorescent antibody technology test. Currently less used.
4. Chest X-ray or CT examination can show signs of pneumonia, lung purulence (void), suppurative pleurisy.
Diagnosis
Diagnosis of nasal sputum
The clinical symptoms of this disease are complex, easy to be confused with pneumonia, lung abscess, tuberculosis, etc., and other sepsis caused by sepsis, osteomyelitis, lung abscess is also difficult to distinguish, chronic type is also easily misdiagnosed as fungus, syphilis, nasal discharge, cloth Brucellosis, etc., and should be distinguished from Pseudomonas aeruginosa, Rhizoctonia and other pseudomonas, in the acute phase should be differentiated from typhoid fever, malaria, staphylococcal septicemia and staphylococcal pneumonia, in subacute or chronic Should be differentiated from tuberculosis.
