Chlamydia
Introduction
Introduction to Chlamydia infection Chlamydia is a pathogen that survives and spreads widely in the human body and belongs to the conditional pathogen. Under certain conditions, it can cause cervical infection, premature labor, abortion and urinary tract infections, especially when combined with other pathogens such as gonococcal infection, and the development of more serious diseases and other complications, in the asymptomatic cervix Men and women, the urinary system often has the presence of Chlamydia trachomatis, and its detection rate is different. When Chlamydia infects human body, it first invades the columnar epithelial cells and grows in the cells, then enters the cells of the mononuclear macrophage system to proliferate. Because Chlamydia reproduces in the cells, the infected cells die, and the fashion can escape the host immune defense function. Obtained intermittent protection, the pathogenic mechanism of Chlamydia is to inhibit the metabolism of infected cells, dissolve and destroy cells and lead to the release of lytic enzymes, cytotoxic effects of metabolites, causing allergies and autoimmunity. basic knowledge The proportion of illness: 0.005% Susceptible people: no special people Mode of transmission: sexual transmission mother-to-child transmission Complications: Infertility
Cause
Cause of chlamydial infection
When Chlamydia infects human body, it first invades the columnar epithelial cells and grows in the cells, then enters the cells of the mononuclear macrophage system to proliferate. Because Chlamydia reproduces in the cells, the infected cells die, and the fashion can escape the host immune defense function. Obtained intermittent protection, the pathogenic mechanism of Chlamydia is to inhibit the metabolism of infected cells, dissolve and destroy cells and lead to the release of lytic enzymes, cytotoxic effects of metabolites, causing allergies and autoimmunity.
Prevention
Chlamydia infection prevention
The outer membrane antigen is the main vaccine candidate antigen, but no breakthrough has been made.
The treatment and prevention of parrot fever pneumonia and chlamydia pneumoniae are seen in the respiratory system.
Daily life prevention:
1. Avoid sexual behavior before there is cure.
2. Prohibit alcohol, do not eat spicy food, drink plenty of water.
3. Do the necessary isolation in the home, bath towels, washbasins, bathtubs, toilets, etc., or disinfect after use.
4. The spouse or sexual partner should go to the hospital for examination and treatment.
5. Pay attention to safe sex in the future, and use condoms correctly in high-risk situations.
Complication
Chlamydia infection complications Complications, infertility
Although men are less likely to have complications due to infection with chlamydia, if they are not treated, the bacteria may cause inflammation of the testicles, which may lead to infertility. If women are infected with chlamydia and are not handled well, the bacteria may cause inflammation of the disc cavity, causing no Breeding, germs can be transmitted to pregnant women by the pregnant women, so that the eyes or lungs of the fetus are infected. Men and women suffer from chlamydia, which can cause eye inflammation, arthritis and urinary tract inflammation syndrome.
Symptom
Symptoms of Chlamydia Infection Symptoms Common Symptoms Urinary Frequent Urinary Urinary Flow Interrupted Urinary Pain Blunt Pain Secretion Herpes Testicular Pain Granuloma
(1) Male chlamydial urethritis, also known as non-gonococcal urethritis (NGU), is a non-acute urethral mucosal inflammatory lesion caused by chlamydial infection.
The incubation period of this disease is longer than that of gonorrhea, about 1-3 weeks or several months, mainly manifested as urinary discomfort, tingling and burning sensation, accompanied by varying degrees of urinary frequency, urgency, dysuria, and dysuria are milder than gonorrhea. The urethral opening is mildly red and swollen with serous or mucopurulent secretions. It is thin and small. It does not urinate for a long period of time. It can be seen in the urethral secretions before the first urination in the morning. It can be seen that the urethra has a "mouth" phenomenon; when there is little secretion In the morning, the urethra is squeezed to produce a small amount of mucus.
Chlamydia trachomatis infection is easy to develop epididymitis, manifested as epididymal enlargement, hardening and tenderness, mostly unilateral, some patients with elevated anti-Chlamydia trachomatis antibody, can directly extract Chlamydia trachomatis from the epididymal aspirate; involving the testis There may be orchitis, manifested as testicular pain, tenderness, scrotal edema and vas deferens hardening and thickening; may occur in the posterior urethra when the prostate is involved, perineal and anal parts dull or tender, may have sexual dysfunction, rectal examination Touching a tender prostate, such as the prostate is obviously swollen, can compress the posterior urethra and appear fine urine flow, urinary weakness and interruption of urinary flow; this disease can also be combined with Reiter syndrome, namely arthritis, conjunctivitis, urethritis triple disease.
(b) Chlamydia infection in the female reproductive system.
Female infection with chlamydia is not limited to the urethra, can affect the entire genitourinary organs, such infections often neglect treatment due to lack of self-conscious symptoms or mild symptoms, causing the source of infection to spread and form a hazard.
Female chlamydial infections have more symptoms than male infections. The main infection site is the cervix, and its sequelae lead to infertility.
Examine
Examination of chlamydial infection
1. Chlamydia cell culture: Cell lines sensitive to Chlamydia trachomatis are McCoy cells, Hela-229 cells and BHK cells. The most commonly used monolayer McCoy cells treated with cycloheximide are stained with monoclonal fluorescent antibody after incubation. Rapid diagnosis, but the operator must be skilled, professional training, the sensitivity of the culture method is 80%-90%, positive to establish a diagnosis.
2. In recent years, fluorescein-labeled monoclonal antibodies against Chlamydia have been used to detect Chlamydia in cell smears. It is convenient to use. Currently, commercial reagents of monoclonal antibodies against Chlamydia Extracellular Membrane Protein (MOMP) are mainly used. The results are judged: Chlamydia number> 10 can be judged as positive.
Diagnosis
Diagnosis and identification of chlamydial infection
diagnosis
(1) Antigen detection
1. Direct application of staining (DT) method Traditional conjunctival scraping and cervical swabs by Giemsa or iodine staining. The presence or absence of inclusion bodies in epithelial cytoplasm is a commonly used screening test for chlamydia. If the operation and specimens are taken properly, their specificity Strong, reliable results, but poor sensitivity, especially iodine staining, can only check inclusion bodies containing glycogen.
2. The cell culture method is used for Chlamydia culture, and the single layer of McCoy cells treated with cycloheximide is usually incubated with fluorescently labeled antibody, enzyme-conjugated monoclonal antibody, iodine or Giemsa stain, and appears in the cytoplasm. The characteristic inclusion body can be considered to have the existence of chlamydia. The sensitivity of this method is 80%-90%. Because the cell culture method is time-consuming and laborious, and the conditions and technical requirements are high, it cannot be used as a routine clinical examination method. Suitable for large-scale screening and epidemiological investigations.
3. Enzyme-linked immunosorbent assay (ELISA) ELISA is an effective method for detecting Chlamydia antigen in clinical specimens. Most of the antibodies used are monoclonal or polyclonal antibodies to Chlamydia lipopolysaccharide, which have strong specificity. This method is used to detect conjunctivitis in infants. The sensitivity and specificity were 88% and 94%, respectively, and the detection rate and specificity of nasopharyngeal infection were 87% and 92%, respectively. 1529 cases of genital tract specimens were detected by this method, and compared with the results of culture method. Sensitive males are 91%, females are 88%, and specificity is 99%. This method is simple and rapid. It is suitable for the detection of a large number of specimens, but cross-reacts with bacteria, which can lead to false positives, especially nasopharyngeal Department specimens.
4. Direct immunofluorescence (DFA) This method is simple, rapid, and specific. The sensitivity and specificity vary with the specimen site and population. The positive rate of neonatal conjunctivitis is 100%, and the tissue culture is 94%. The pharyngeal specimen has a sensitivity of 85% and a specificity of 75%. The specimens of the endometrium and fallopian tubes are more sensitive than the culture method. It is also used for the detection of semen, intestines, and inactivated specimens of chlamydia due to improper transportation or preservation. Polyclonal fluorescent antibody detection can be used to diagnose Chlamydia infection, but its type cannot be distinguished. Monoclonal fluorescent antibodies can be directly typed to identify native corpuscles of Chlamydia trachomatis, rather than large and rare intracellular inclusions, fluorescence microscopy. The quality and handling techniques can affect the results. For the skilled practitioners, the sensitivity and specificity of this method is at least the same as that of ELISA. DFA can replace the cell culture method to screen the moderate to highly prevalent population of genital tract infections. Diagnosis of symptomatic neonatal conjunctivitis.
5. Dot immuno-binding method (DIBA) This method uses a microporous membrane as a solid phase carrier, and the antigen-antibody reaction after adsorption of the antigen has a positive result on the membrane. The sensitivity is 100% and the specificity is 92. 4%, compared with the cell culture method, the coincidence rate is 96.7%, DIBA is suitable for the detection of large-scale specimens, but the result takes 3 days.
6. Nucleic Acid Probes With the development of molecular biology techniques, DNA hybridization technology has entered the field of chlamydia detection. The probes prepared with 82S-labeled 7Md plasmids have detected sensitivity and specificity of Ct of 91% and 80%, respectively. The plasmid DNA of Chlamydia pneumonia granuloma (LGV)-II and the chromosomal DNA of LGV-I can be used as probes to specifically detect 15 serotype antigens of Chlamydia trachomatis, and herpes simplex virus (HSV), Neisseria gonorrhoeae, etc. 41 kinds of microorganisms have no cross-reaction, the detection range can reach 10100pgDNA, and some specimens which are negative by serology, monoclonal antibody and tissue culture can be positively detected by DNA probe, and Chlamydia trachomatis TE-55 strain is used. The whole DNA preparation molecular probe can specifically detect 15 serotypes of Chlamydia. The probe has high specificity and high sensitivity, and is completely possible for clinical diagnosis and molecular epidemiological investigation of Chlamydia. DNA hybridization is used for cervical smear and rectal biopsy specimens. The results are similar to those of culture, but it is also believed that DNA probes are not sensitive enough in genital tract specimens, especially for cultures that are weakly positive. This.
7. Polymerase chain reaction (PCR) PCR is a new technology developed in recent years. It can amplify nucleic acid molecules in geometric progression, rapidly amplify a very small number of nucleotide molecules in a sample, and then obtain a pole by detecting nucleic acid molecules. Sensitive results, PCR is simple and rapid, with high sensitivity and specificity, and can directly identify the species and type of Chlamydia from the specimen, and select a pair of species-specific primers from 7.5Kb plasmid ORF-3. After 40 PCR cycles, the sensitivity of electrophoretic detection reached 10-17 g of DNA.
(B) antibody detection antibody value is not large, because the genital tract infection without complications still produce low titer antibodies; about 20% of patients with acute chlamydial urethritis do not produce antibodies; some people think that IgA means the current infection, but The PID can have long-term IgA, and the common methods for detecting chlamydial antibodies are as follows.
1. The complement fixation test (CFT) is suitable for the diagnosis of LGV, parrot fever and Chlamydia pneumoniae infection. Its sensitivity is low. When the titer is 1:32, it indicates that it is a Chlamydia infection, but its type cannot be identified. It is used for the confirmation test of LGV. The required potency is 1:64.
2. Microindirect immunofluorescence assay This test is one of the most sensitive methods for diagnosing Chlamydia pneumoniae infection. It is tested with Chlamydia pneumoniae as an antigen to detect specific antibodies, if the double serum titer is increased by 4 times, or the serum IgM antibody is single-effect. The price is 16, or the IgG antibody titer is 512, which can be diagnosed as acute infection. The IgG antibody titer of the previously infected person is between 8 and 256. Clinically, according to the serological test, the Chlamydia pneumoniae infection can be divided into primary and Secondary to the two, the primary infection IgM appears early, the titer is high, IgG appears later, IgA reaction is weak or does not appear, secondary infection IgG response is rapid, generally do not appear IgM and CF antibodies, therefore, antibody detection should be based on The time of specimen collection, combined with the comprehensive analysis of clinical data, can draw correct conclusions.
The pathogen cultures Chlamydia trachomatis.
