GB 17012-1997 Diagnostic criteria and treatment principles for infectious diarrhea
Some standard content:
【GB17012—1997】
Diagnostic criteria and treatment principles for infectious diarrhea Preface
Infectious diarrhea refers to diarrhea caused by various pathogens in the intestine. This standard only refers to infectious diarrhea other than cholera, malaria, typhoid fever, and paratyphoid fever. It is a Class C infectious disease stipulated in the "Law of the People's Republic of China on the Prevention and Control of Infectious Diseases". It mainly includes intestinal infections caused by pathogens such as bacteria, viruses, and protozoa. The more common ones are Salmonella enteritis, enterodiarrhea-causing Escherichia coli enteritis, diarrhea-causing Vibrio enteritis, Campylobacter jejuni enteritis, Yersinia enterocolitica enteritis, rotavirus enteritis, and Giardia lamblia enteritis. The clinical manifestations can include abdominal pain, diarrhea, and symptoms such as fever, nausea, and vomiting; the treatment principles are also similar, but diarrhea caused by different pathogens has different characteristics in epidemiology, pathogenesis, clinical manifestations, and treatment. Some are inflammatory diarrhea, and some are secretory diarrhea. The final diagnosis must rely on etiological examination.
Infectious diarrhea is a common and frequently occurring disease in my country, especially in summer and autumn. The formulation of this standard is of great significance to the prevention and treatment of this group of diseases. According to the provisions of the "Law of the People's Republic of China on the Prevention and Control of Infectious Diseases" and the "Implementation Measures of the Law of the People's Republic of China on the Prevention and Control of Infectious Diseases", the diagnostic criteria and treatment principles of this group of diseases are formulated. Appendix A of this standard is a prompt appendix.
This standard is proposed by the Ministry of Health of the People's Republic of China. This standard is drafted by the Institute of Epidemiology and Microbiology of the Chinese Academy of Preventive Medicine and the First Hospital of Peking University Medical College.
The main drafters of this standard are: Zhang Shubo, Chen Jingjing, Xiao Donglou, Shen Baoquan, and Wang Qinhuan. This standard is interpreted by the Chinese Academy of Preventive Medicine, the technical unit entrusted by the Ministry of Health.
1 Scope
This standard specifies the diagnostic criteria and treatment principles for infectious diarrhea other than cholera, malaria, typhoid and paratyphoid
This standard applies to the diagnosis and prevention of infectious diarrhea within this scope by medical and health epidemic prevention institutions at all levels
2 Definitions
This standard adopts the following definitions.
2.1 Inflammatory diarrhea Inflammatory diarrhea refers to diarrhea caused by pathogens invading intestinal epithelial cells, causing inflammation. Often accompanied by fever: the stool is mostly mucous or purulent, and there are more red and white blood cells under microscopic examination, such as invasive Escherichia coli enteritis, Campylobacter enteritis, etc.
2.2 Secretory diarrhea Secretory diarrhea refers to diarrhea caused by pathogens stimulating intestinal epithelial cells, causing increased intestinal fluid secretion and/or absorption disorders. Most patients do not have fever, and the stool is mostly watery. There are not many red and white blood cells under microscopic examination, such as enterotoxigenic Escherichia coli enteritis, rotavirus enteritis, etc. 3 Diagnostic principles
The causes of diarrhea are relatively complex. In addition to pathogens such as bacteria, viruses, and parasites that can cause infectious diarrhea, other factors, such as chemicals, can also cause non-infectious diarrhea. Therefore, the diagnosis of this group of patients must be based on epidemiological data, clinical manifestations, and routine stool examinations. Since this group of diseases covers a wide range, and the above data are basically similar, the diagnosis of the pathogen must be based on the detection of relevant pathogens from feces, or specific nucleic acids, or specific antibodies from serum.
4 Diagnostic criteria
4.1 Epidemiological data
The disease can occur in all four seasons of the year, and is generally more common in summer and autumn. There is a history of unclean food (water) and/or contact with diarrhea patients, diarrheal animals, and bacteria-carrying animals, or a history of traveling to underdeveloped areas. If it is food-borne, it is often a collective disease and there is a history of eating suspicious food together. Infections such as certain salmonella (such as Salmonella typhimurium), enteric diarrheagenic Escherichia coli (EPEC), group A rotavirus and coxsackievirus can cause outbreaks in the nursery. 4.2 Clinical manifestationsbzxZ.net
4.2.1 Diarrhea, bowel movements ≥ 3 times a day, abnormal stool characteristics, which may be loose stools, watery stools, mucus stools, bloody stools or bloody stools, and may be accompanied by nausea, vomiting, loss of appetite, fever, abdominal pain and general discomfort. In severe cases, dehydration, electrolyte disorders and even shock may occur due to the loss of a large amount of water.
4.2.2 Cholera, leukemia, typhoid fever and paratyphoid fever have been excluded. 4.3 Laboratory examination
4.3.1 Routine stool examination: The stool may be loose stools, watery stools, mucus stools, bloody stools or bloody stools. Microscopic examination may show a large number of red and white blood cells, or a small number or no cells. 4.3.2 Pathogenic examination (see Appendix A for details): Pathogenic microorganisms other than cholera, dysentery, typhoid and paratyphoid may be detected in feces, such as enterodiarrhea Escherichia coli, Salmonella, rotavirus or Giardia lamblia, etc. Or specific antigens, nucleic acids or specific antibodies can be detected from serum.
Clinical diagnosis: For those who meet 4.2.1, 4.2.2 and 4.3.1, 4.1 is for reference. Pathogenic diagnosis: Clinical diagnosis plus 4.3.2. 5 Principles of prevention and treatment
5.1 Principles of treatment
5.1.1 General and symptomatic treatment: Pay special attention to improving the symptoms of poisoning and correcting the imbalance of water and electrolytes.
5.1.2 Pathogenic treatment: Give corresponding pathogenic treatment when necessary for the pathogen causing diarrhea.
5.1.3 Nutritional treatment: Such patients often have nutritional disorders. If the condition permits, they should continue to eat (feed) appropriate food. 5.2 Principles for handling multiple outbreaks and outbreaks
5.2.1 Isolate and treat patients immediately.
5.2.2 Take samples for etiological and/or serological examinations to identify the pathogen as soon as possible. 5.2.3 Identify the source of infection as soon as possible, take appropriate measures to cut off the transmission route, and block the development of the epidemic.
5.3 Principles of prevention
The main focus should be on cutting off the transmission route, while strengthening the management of the source of infection and taking comprehensive preventive measures. Special attention should be paid to preventing outbreaks and epidemics for key populations, collective units and temporary large-scale construction sites.
A1 Test for Salmonella
A1.1 Collection of specimens
Appendix A
(Indicative Appendix)
Etiological diagnosis method
When diarrhea is prevalent or breaks out, the number of specimens to be collected shall be determined based on the number of victims and their distribution range. The collected stool specimens shall be sent for examination as soon as possible. If the transportation time exceeds 2 hours, the specimens shall be placed in Cary-Blair transport medium and sent for examination under ice bath conditions. A1.2 Isolation method
Generally, stool is inoculated with a strong selective culture medium (such as SS agar) and a weak selective culture medium (such as MacConkey plate) and cultured at 37°C. Suspicious colonies are selected from the culture for further biochemical identification.
Al.3 Serological identification
Use O, H, and Vi factor sera to conduct slide agglutination tests with the strain to be tested. First, use O factor serum to determine the O group to which it belongs and the various components of its O antigen, then use H factor serum to check its first and second phase H antigens to determine the serotype, and use Vi serum to check if necessary. A1.4 Determination of bacterial type and result report
Combined with the biochemical reaction and serological test results, check the antigen table, determine the bacterial type and report the results.
A2 Test for enterodiarrhea Escherichia coli
A2.1 Collection of stool specimens from patients (same as A1.1)A2.2 Isolation and culture
Use an inoculation loop to dip fresh stool specimens and inoculate them in the following culture media: a) MacConkey agar or eosin-methylene blue agar, which are selective identification media with weak inhibition on E. coli. E. coli ferments lactose and forms pink opaque colonies on MacConkey agar;
b) Sorbitol MacConkey agar (1% sorbitol is used instead of lactose). Enterohemorrhagic E. coli and some enteropathogenic E. coli slowly ferment sorbitol and form colorless colonies; c) Blood agar plate, which is used to observe hemolysis of enteropathogenic E. coli and to distinguish it from other colonies.
After the specimen is inoculated into the culture medium, culture it at 37℃ for 18-24h and observe the results. A2.3 Preliminary identification
Pick suspicious colonies for biochemical reaction and slide agglutination test with E. coli polyvalent serum, and further identify those that are positive
A2.4 Identification
A2.4.1 Enteropathogenic E. coli (EPEC) a) Specimen: Watery or egg drop soup stool of infants and young children: b) Biochemical reaction is consistent with the characteristics of E. coli: c) Serological identification is consistent with the EPEC serotype (Table A1). Table A1 O serogroups and serotypes of common enteropathogenic E. coli O
Infant warm diarrhea
1) Non-motile variants,
OKntH,
OustHu
OusaiHae
OiuenHa
Warm diarrhea in adults and children
A2.4.2 Enterotoxigenic Escherichia coli (ETEC) a) Specimen: Cholera-like watery stool:
b) Biochemical reaction is consistent with the characteristics of E. coli
c) Serological identification is consistent with the ETEC serotype (Table A1); EHEC
d) Detection of E. coli heat-labile enterotoxin (LT) and/or heat-stable enterotoxin (ST). LT can be determined by immune intestinal segment ligation test, skin test, ELISA, Biken test, plate immunohemolysis test, DNA probe hybridization and polymerase chain reaction (PCR). Each laboratory can choose one of them according to its conditions and habits. A2.4.3 Enteroinvasive Escherichia coli (EIEC) a) Specimen: bacillary dysentery-like stools;
b) Biochemical reaction: no or slow fermentation of lactose, no gas production, no motility except O124, negative for tartrate, negative for lysine decarboxylase: c) Serological identification consistent with EIEC serotype (Table A1): d) Positive in guinea pig corneal conjunctival test (Sereny test) or Hela cell invasion test. A2.4.4 Enterohemorrhagic Escherichia coli (EHEC) a) Specimen: watery stools in the early stage and bloody stools later: b) Biochemical reaction: slow fermentation of sorbitol, white colonies on sorbitol MacConkey agar plates;
c) Serological identification: serotype O157:H, or O26:K62:H11 (Table A1) d) Produces Vero cytotoxicity (VT).
A3 Diagnosis of diarrhea-causing Vibrio
A3.1 Collection of stool specimens from patients (same as A1.1, specimens are transported and stored at room temperature).
A3.2 Isolation and culture
A3.2.1 Direct isolation: The collected specimens can be directly plated on the separation medium and cultured at 37°C overnight. The culture medium can be non-selective or selective. Commonly used non-selective culture media include nutrient agar and agar containing 5% sheep blood cells. Selective culture media include Vibrio agar, gentamicin agar, No. 4 agar, TCBS, etc. A3.2.2 Isolation after enrichment: After receiving the specimen, inoculate alkaline protein water while directly isolating, and after enrichment at 37°C for 6 to 8 hours, plate on selective or non-selective culture medium and culture at 37°C overnight.
A3.3 Preliminary identification
Select suspicious colonies for oxidase, motility, 0/129 sensitivity tests and slide agglutination tests for 01 and O139 Vibrio cholerae diagnostic sera. Those that meet the characteristics of Vibrio but do not agglutinate in 01 and O139 Vibrio cholerae diagnostic sera are further systematically identified. Those that agglutinate in 01 or 0139 diagnostic sera can be reported as 01 or 0139 group Vibrio cholerae and handled according to the corresponding standards. A3.4 Identification
Further systematic identification is performed on the detected Vibrio, and the results are determined according to Table A2 Table A2 Pathogenic Vibrio Identification Table
Optimum growth rate, C
Chemistry
Nitrate reduction
Indole
Urea
L-glutamic acid
L-isinic acid
L-arginine
Glucose gas production| |tt||Maihua sugar
D-glycol
L-arabinose
Fiber second stall
Salicin
Gelatinase
Grow in different salt broth
0%NaCI
0/129 scattered sensitivity
TCBS growth
Accessory blood
Note: Ten southern reactions, one negative zone should be, ten! or
Cincinnamonella
Tijiang bacteria
River blue
Fernian
Egg-combed fish Vibrio
|Violentivirus
/+Indeterminate reaction. S sensitive, R resistant, Y yellow. G dry color A4
Testing of Campylobacter jejuni
A4.1 Collection of specimens (same as A1.1)
A4.2 Examination of specimens
Hollis
The feces of patients in the acute phase can be directly smeared, Gram-stained or stained with 0.3% alkaline fuchsin. Microscopic examination shows Gram-negative, slender, curved, S-shaped or "seagull wings" shape, and no spores. Liquid specimens can be seen under a dark field microscope with "shooting target"-like dynamics.
A4.3 Isolation and culture
This bacterium is a microaerobic bacterium and grows best when there is 5% oxygen. In addition, carbon dioxide is required. The following methods can be used: ① mixed gas method; ② candle jar culture method. The culture media used for isolation include Brucella agar, Campy-BAP medium, Skirrow medium, egg yolk saline medium, chocolate pig blood agar and blood iron salt medium. In order to inhibit the growth of miscellaneous bacteria and improve the detection rate, vancomycin (6 mg/L), amphotericin (2 mg/L), sulfonamide enhancer (5 mg/L) and polymyxin B (4 mg/L) can be added to the culture medium. A4.3.1 Direct isolation and culture: Use Brucella agar and other medium for isolation and culture. Take a few inoculation loops of feces and streak them on the isolated blood. Culture them in a microaerobic environment at 37°C or 42°C for 1 to 3 days. If no growth is observed, continue to culture for 1 to 2 days. Campylobacter jejuni and Campylobacter coli should be cultured at 42°C, and Campylobacter fetus should be cultured at 37°C. A4.3.2 Isolation and culture after enrichment: Place about 0.1g of stool specimen in liquid enrichment culture medium, culture at 42℃ microaerobic conditions for 2-3 days, and then separate and culture with one of the aforementioned culture media.
A4:3.3 Preliminary identification: According to the production of catalase, Campylobacter can be divided into two groups. Those that produce catalase are Campylobacter fetus and Campylobacter jejuni coli, and those that do not produce catalase are Campylobacter spp. Pick suspicious colonies from the isolation culture medium, observe the morphology under a microscope, and observe the motility under a phase contrast microscope. At the same time, the culture is smeared, and Gram staining confirms that it is a Gram-negative small rod. At the same time, the oxidase and catalase tests are both (10). Further identification can be made for cultures that meet the characteristics of Campylobacter. A4.4 Biochemical test
Does not ferment or oxidize sugars, V-P, methyl red, indigo matrix, citrate, urea, malonate, gelatin. Cholera red test is negative. Negative for lysine and ornithine decarboxylase, does not decompose arginine, has no lipase activity, and does not produce pigments. Positive for oxidase and catalase. On TTC medium, the bacterial lawn is purple and shiny, and on the surface of glycine medium, it grows like mist.
A4.5 Serological typing
After the biochemical reaction confirms that it is Campylobacter jejuni, passive hemagglutination test or slide agglutination test can be used for serological typing
A5 Inspection of Yersinia enterocolitica
A5.1 Collection of specimens (same as A1.1)
A5.2 Isolation method
It can be directly inoculated on selective agar flat blood such as SS agar or MacConkey medium, and cultured at 22-30℃ for 24-48h. At the same time, take about 1g of the specimen and inoculate it in 10mL of pH7.4-7.6 PBS, mix well, and place it at 0-4℃. Take the enriched culture after 1 day and 3 weeks of culture, and separate and culture it according to the above method. At the same time, transfer it to the improved magnesium chloride malachite green enrichment solution or other enrichment solution, and culture it at 22-30℃ for 1-2 days before separation.
A5.3 Select suspicious colonies
Yersinia grows on MacConkey (MAC) medium, and reaches 1-2mm in 24 hours at 25℃, and 3mm in 48 hours. The colonies are grayish white or pink, and do not ferment lactose. Some strains have an irregular transparent edge. If the colonies are observed with a dissecting microscope or microscope, it is easier to identify. Select translucent, smooth, and non-cyan colonies. The colonies of Yersinia grown on SS medium are similar to those on MAC medium, but slightly smaller. The colonies are smooth and colorless, and the size is similar to that of Bacillus colonies. Three sugar iron culture medium can be planted, and observations can be made once every 1, 2, and 7 days. The strains that produce acid but no gas on the slant and bottom surface and are negative for H2S can be further identified. A5.4 Biochemical identification
The identification of Yersinia mainly relies on biochemical reactions, which are characterized by negative results for oxidase, phenylalanine deaminase, lysine and arginine decarboxylase, most strains are motile at 22-25°C, and a few strains are non-motile; they are non-motile at 37°C, and are positive for methyl red, urease, nitrate reduction, ornithine decarboxylase and β-galactosidase, and can ferment mannitol, mannose, sorbitol and L-arabinose.
A5.5 Serological examination
This bacterium has bacterial O antigen and flagellar H antigen. The bacterium can be divided into different serotypes using more than 80 O antigen factors commonly reported internationally. At present, there are 54 serotypes reported in my country.
A6 Rotavirus test
A6.1 Collection of stool specimens
Collect about 10g or 10mL of stool from patients with early diarrhea, place it in a sterile test tube, transport it to the laboratory in a refrigerated container, and store it at -20℃ until testing. A6.2 The specimen can be tested by one of the following two methods A6.2.1 ELISA test method: There are commercial kits available in China, and they can also be prepared by yourself. The test is carried out according to the conventional method.
A6.2.2 Rotavirus RNA polyacrylamide gel electrophoresis test method: It is carried out according to the conventional method, and the results are determined based on the electrophoresis pattern.
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