Melioidosis
Introduction
Introduction to the nose It is an infectious disease caused by Burkholderia sinensis. It is a kind of infectious disease caused by single hoofed animals such as horses, donkeys and crickets. People are infected by contact with sick animals or articles infected with pathogenic bacteria. The clinical manifestations are mainly acute fever, cellulitis, necrosis, abscess and granuloma in the respiratory tract, skin, muscles, etc. Some are chronic, intermittent, and the course of disease can last for several years. In 330 BC, Aristotle recorded the disease and named it in the Latin word "Malleus" (malignant meaning). Apeyrtos (AD 375) observed the occurrence of nasal discharge in horses. Royer (1837) first described human snot, Löffer and Schütz (1882) first detected pathogenic bacteria from horses that died of snot. In 1985, the bacterium was named Pseudomonasmallei. basic knowledge Sickness ratio: 1-2% Susceptible people: no specific people Mode of infection: contact spread Complications: bacteremia, pneumonia
Cause
Cause of nasal discharge
(1) Causes of the disease
The pathogen of this disease is Burkholderia mallei. This strain has been easily genus. It has been named as F. faecalis (1918), Actinobacillus sinensis (1933), and the nose is not moving. Bacillus (1964), Pseudomonas sinensis (1966), etc., in 1993, internationally based on the biological characteristics of the newly discovered bacteria, it was listed in Burkholderia, due to domestic The abbreviation of B. sinensis is still widely used, so this section also uses this name. Bacillus sinensis is a Corynebacterium brevis, which varies in size from 2 to 5 m in length and 0.5 to 1.0 m in width. It is isolated and sometimes paired. Arranged, no flagella can not move, no capsule, no spores, Gram stain negative, mostly in the pus free of extracellular, sometimes seen in the cells, the bacteria for aerobic, temperature in 37 ~ 38 °C, pH 6.8 ~ 7.0 growth is most suitable, the bacteria growth is not good on ordinary medium, but developed well in 1% ~ 5% glycerin broth, can produce a layer of light yellow honey on the potato medium The lawn moss gradually turns brownish red, and the bacteria grows slowly. It usually takes 48 hours, and the normal colonies are smooth ( S), the colony after the mutation may appear rough (R), wrinkle type (C), dwarf (D), mucus type (M) or pseudo-membrane type (P), etc., the bacteria should be associated with the snot-like Burke Hall Identification of the bacteria phase, the main points are shown in Table 1, B. sinensis can produce two antigens, namely specific polysaccharide antigen and common antigen (protein component), the latter and the Rhizoctonia sinensis in the agglutination test and skin test cross, the bacteria Does not produce exotoxin, the protein part of the toxin in the bacteria, mallein, can cause allergic reactions in infected animals, can be used as a skin test antigen for diagnosis, the bacteria is more resistant, in feces, urine can be Survival for 4h, survival in water for 70 days, sterilized tap water for 6 months, but only survive for 10 to 15 days in dry environment, direct sunlight for 24h or heating for 56min C for 15min can die, boil immediately die, at 3% Coal phenol soap solution, 10% lime milk, 2% formaldehyde can be killed in 1h.
(two) pathogenesis
The disease is mainly transmitted through contact, and the bacteria invade the human body through damaged skin and mucous membranes, and are also found through respiratory tract and digestive tract infection.
Prevention
Bowel prevention
1. Elimination of the source of infection must first eliminate the prevalence of snot among horses.
(1) Detection: The application of the nasal sputum eye drop test can identify infected and uninfected horses, that is, the drop of nasosin into the conjunctival sac of the horse eye, at the 3rd, 6th, 9th, 24th hour after the eye drop Observe the reaction, such as conjunctivitis, and the secretion of purulent eyelids is a positive reaction.
(2) Isolation: According to the test results, the equine fauna is divided into three groups: diseased group, suspected infected group and assumed healthy group. Isolation and observation of suspected infection groups, hypothetical healthy groups, after 6 months of observation, no longer can the disease can be released. Horses that have been in contact with sick animals should be isolated for 3 weeks even if their eye test is negative.
(3) culling: The infected horses, regardless of their symptoms, should be killed and buried immediately without bloodletting.
2. Clear the route of infection: thoroughly disinfect the contaminated horseshoes with chlorine and lime. Contaminated litter and feces can be used after being treated by stacking mud fermentation, high temperature, etc.
3. Protect susceptible populations: educate people engaged in horse work on prevention knowledge, and pay special attention to the disinfection of excreta and pollutants. For laboratory workers engaged in the testing of B. sinensis, attention must be paid to aseptic handling and disinfection. Medical observation of suspected infected people for 3 weeks. When a patient is found, he should be treated under strict conditions and discharged after healing.
Complication
Bowel complications Complications bacteremia pneumonia
Entering the blood can cause bacteremia, and can also cause pneumonia, multiple visceral abscesses, multiple arthritis or death.
Symptom
Nasal symptoms Common symptoms Oral mucosa ulcer Nasal septum perforation Lymph node swelling Diarrhea Joint pain Low fever Septic black sputum with bloody pus
The incubation period of human sputum varies greatly, usually from several hours to three weeks, with an average of 4 days, or even delayed to 10 years. There are two types of acute and chronic clinical.
1. Acute onset of acute nasal discharge, acute cellulitis in the skin infection site, local swelling, followed by necrosis and ulceration, formation of marginal irregularities, gray ulceration, and gray-yellow exudate, nearby lymph nodes Swelling, multiple lymph nodes and subcutaneous nodular abscess appear in the lymphatic vessels. After the abscess is broken, red or grayish white pus is discharged. The mouth is very difficult to heal, and the fistula can be formed. If the pathogenic bacteria invade from the upper respiratory tract, the nose can be made. Cellulitis, nasal cavity, oral mucosal ulcer and necrosis, nasal septum perforation, fistula and pharynx also have ulcers, often discharge bloody secretions, and then discharge purulent secretions, pathogens can also invade the lower respiratory tract, resulting in Usually accompanied by systemic violations, headache, chills and irregular fever, body aches, lack of appetite, vomiting, diarrhea and splenomegaly, patients often extreme exhaustion, clinically similar to typhoid or disseminated tuberculosis, later due to the face, Abscess can occur in the neck, trunk and limbs, often resulting in circulatory failure due to sepsis.
2. Chronic nasal discharge begins to show systemic symptoms, only low fever or long-term irregular fever, sweating and limbs, joint pain, later, sepsis or sepsis, skin or soft tissue abscess, nearby lymph nodes Sometimes, abscesses and ulcers flow out a lot of pus, can also form a long-term unhealed fistula, joints, bone marrow, liver, spleen, lung, eye and central nervous system can be involved, the disease develops slowly, when the time is good, the duration of the disease From month to year, the patient gradually gains weight and is a cachectic condition, often dying due to gradual failure or sudden deterioration, and there are cases of self-healing.
Examine
Nasal examination
1. Pus or secretion smear examination and culture smear can be used for methylene blue, Jimsa, Reiter and other staining, visible two-pole concentrated bacilli, but not easy to distinguish with Burkholderia sinensis, recently Fluorescent antibody staining method has the highest specificity, and the culture can also obtain positive possibility. The sample with more contaminated bacteria is not easy to be directly isolated and cultured. The Strauss reaction is often performed, that is, the sample is ground with physiological saline to make 5-10. Double-milk system, after applying 1000 U of penicillin per ml for 3 hours at room temperature, the supernatant was taken to give 0.5 ml of male guinea pigs weighing about 250 g, and guinea pigs developed scrotal swelling, testicular meningitis and orchitis after 3 to 5 days, and then suppurate. , rupture, more than 2 to 3 weeks of death, if necessary, guinea pigs can be necropsy after death, using pus for bacterial culture separation, further confirmed.
2. Blood culture with sepsis can give positive results, and the general patient's positive rate is not high.
3. Immunological examination of serum can be used for hemagglutination and complement fixation test, the former is more sensitive, the titer is more than 1:640 to have diagnostic value, the latter specificity is strong, but the operation is troublesome, titer > 1:20 Only a reference value has been established, and a simple solid phase complement binding test has been established. The difference between the diameter of the hemolytic ring of the control hole and the test hole is more than 6 mm, and it is positive. Recently, a new method of nasal sputum test, such as indirect latex agglutination test, has been applied. , convective immunoelectrophoresis test, spot enzyme-linked immunosorbent assay, single-diffusion hemolysis test, fluorescent antibody test and gene probe method, etc., but not widely used in China, intranasal test of nasosin: ascorticin 1: After 1000 dilution, 0.1 ml was injected into the forearm skin. After 24 to 48 hours, the local redness was positive, and it was positive within 4 weeks of the disease, which lasted for several years.
4. Acute lung infection, chest X-ray shows lobar pneumonia or increased density of localized density.
Diagnosis
Nasal diagnosis
The clinical manifestations of snoring are complicated, often difficult to diagnose, contact with diseased horses or epidemiological history of pathogenic bacteria treated in the laboratory, secretions, puncture and blood culture, serological examination (blood Condensation and solid phase complement binding test), intranasal test of nasosin, vaccination of infected guinea pigs, etc., all contribute to the diagnosis of this disease.
Clinically, it should be differentiated from snoring, sporotrichosis, streptococcal cellulitis, staphylococcal infection and disseminated tuberculosis.
