Gonococcal infection

Introduction to gonococcal infection It refers to the purulent infection of the genitourinary system caused by Neisseria gonorrhoeae (NG, referred to as Neisseria gonorrhoeae). It is one of the common sexually transmitted diseases, commonly known as gonorrhea. Clinical manifestations are more common with urethritis and cervicitis. Typical symptoms are dysuria, frequent urination, urgency, dysuria, discharge of mucus or purulent discharge. It can also invade the eyes, pharynx, rectum and pelvis, as well as blood-borne disseminated infections causing arthritis, perihepatitis, sepsis, endocarditis or meningitis. basic knowledge Probability ratio: The incidence rate is about 10% in high-risk sexual behaviors Susceptible people: no special people Mode of transmission: sexual transmission, contact transmission Complications: prostatitis pelvic inflammatory disease endometritis

Neisseria gonorrhoeae infection

Unclean sex (95%)

Neisseria gonorrhoeae infection can cause gonorrhea, the main cause is sexual uncleanness, spread by sexual contact, the disease is extremely easy to re-infect, and can cause a variety of serious complications, such as failure to cure in time, the most serious consequences can lead to death.

Neisseria gonorrhoeae are Gram-negative oval or spherical bacteria, often arranged in double arrangement. The contact surfaces of the two bacteria are flat or dimpled, the size is 0.6-0.8m, no flagella without capsule, no spore formation, in pus Neisseria gonorrhoeae is located in white blood cells and grows well on medium containing animal protein. The optimum pH for growth environment is 7.0-7.5, the optimum temperature is 35-36 °C, and it is in 5%-10% carbon dioxide environment. The culture period can be shortened. After 20~48h, the colonies are observed to be round, convex, moist, smooth, translucent, grayish white, and petal-like at the edges. According to the size of the colony, the gloss is divided into five types: T1 and T2. T1 and T2 The colonies are toxic strains, and there are pili on the surface of the bacteria; T3, T4 and T5 are non-toxic strains, the surface of the bacteria is sterile, and the pili is related to the invasiveness of Neisseria gonorrhoeae. Although Neisseria gonorrhoeae has endotoxin, it is poisonous. The relationship is not big.

The gonococcal surface antigen regulates the relationship between the host and the parasite, which is an important part of its pathogenicity and immunity. There are three types of surface antigens:

1 pilin protein antigen;

2 lipopolysaccharide antigen;

3 outer membrane protein antigen, Neisseria gonorrhoeae has weak resistance to the external environment, is not resistant to dryness and hot and cold, died in the dry environment for 1 to 2 hours, heated to 55 ° C for 5 minutes, inactivated, died within 1 to 2 days at room temperature, for general chemistry Both disinfectants and antibiotics are sensitive.

Pathogenesis

Under normal circumstances, the urine should be sterile. Because the urine continuously flushes the urethra, it is difficult for the invading microorganisms to settle in the urinary tract. The gonococcal bacteria are easily parasitic on the anterior urethra, the cervix, the posterior urethra, and the bladder mucosa. Since these mucosa have a single layer of columnar epithelial cells and transitional epithelial cells, the pilus on the gonococcus is very easy to adhere to the above cells, and the gonococcus is quickly killed in acidic urine (pH < 5.5), thus the bladder and kidney Not easily infected.

Prostatic fluid contains spermine and zinc, so it can be infected by gonococcal bacteria. The parasitic flora in the urethra and vagina has a certain inhibitory effect on the growth of Neisseria gonorrhoeae. The presence of these flora provides some natural resistance to the body. Mucosa Lactoferrin is present on the surface. Iron is essential for the growth and reproduction of Neisseria gonorrhoeae. For example, when the concentration of iron in the environment is low, the growth of Neisseria gonorrhoeae is limited. The sensation of Neisseria gonorrhoeae to different cells is different for the anterior urethra mucosa. Columnar epithelial cells are most sensitive, so the anterior urethra is most susceptible to infection.

The posterior urethra and bladder mucosa are composed of transitional epithelial cells. Neisseria gonorrhoeae is less sensitive than columnar cells. Therefore, the chance of infection by gonococcal bacteria is worse than that of the anterior urethra. The scaphoid mucosa is composed of stratified squamous cells, and the multi-layered squamous Epithelial cells are not easily infected by gonococcal bacteria.

Neisseria gonorrhoeae rapidly adheres to the urethra and cervical epithelium by means of pili, protein and IgA decomposing enzyme, and the outer membrane protein-1 of Neisseria gonorrhoeae is transferred to the epithelial cell membrane of the urethra. The Neisseria gonorrhoeae are phagocytosed by columnar epithelial cells and then transferred to the extracellular mucosa. Through the synergistic action of endotoxin lipopolysaccharide, complement and IgM, it causes an inflammatory reaction, which causes extensive edema and adhesion of mucous membranes around 30h, and purulent secretions appear. When urinating, the urethral mucosa is expanded. Stimulate local nerves to cause pain, due to inflammatory reaction and mucosal erosion, shedding, forming a typical purulent discharge of the urethra.

As the inflammation stimulates the contraction of the urethral sphincter spasm, frequent urination, urgency, and if there are small mucosal ruptures at the same time, terminal hematuria occurs. After the bacteria enter the urethral glands and crypts, the mucosa can also invade the submucosa, blocking the ducts and fossa. Opening, causing local abscesses, in this process, the body produces antibodies locally and systemically, the body's immune performance against Neisseria gonorrhoeae in all aspects, the host defense against Neisseria gonorrhoeae immunity depends mainly on IgG and IgM, and IgA can also be on the mucosal surface To prevent infection, male urethral secretions of gonococcal urethritis often produce an antibody response to infected gonococcal bacteria, which is a mucosal antibody response.

These antibodies have IgG and IgM in addition to IgA. In serum antibody response, serum IgG, IgM and IgA levels are elevated after gonococcal infection, and IgA is a secretory antibody that enters the bloodstream from the mucosal surface. - Complement-mediated bactericidal action is very important, they have a protective effect on gonococcal bacteremia caused by serum-sensitive strains. Generally, inflammation does not spread to the whole body. If the drug is symptomatic, sufficient amount, local inflammation will slowly subside, inflammation After regression, the necrotic mucosa is repaired and replaced by squamous epithelium or connective tissue.

Severe or repeated infection, connective tissue fibrosis, can cause urethral stricture, if not treated promptly, Neisseria gonorrhoeae can enter the posterior urethra or cervix, and spread upwards to cause inflammation of the genitourinary tract and nearby organs, such as paraurethralitis, urethral ball Adenitis, prostatitis, seminal vesiculitis, epididymitis, endometritis, etc., severe cases can be spread to the whole body by blood, gonococcal can also lurk in the deep part of the glandular tissue for a long time, become the cause of recurrent episodes of chronic gonorrhea, these are infected Connective tissue fibrosis after organ inflammation subsides can cause stenosis or tubal stenosis, obstruction, secondary male infertility and ectopic pregnancy.

Neisseria gonorrhoeae infection prevention

Avoid non-marital sexual contact.

The used items of the patient should be disinfected. The Neisseria gonorrhoeae is very fragile after leaving the human body. It dies within 1~2 hours in a dry environment, boiled, and exposed to sunlight. The commercially available disinfectant containing bleaching powder and iodine has a good bactericidal effect.

To avoid infection in public places, you should use a squat toilet.

Implement a system of neonatal silver nitrate solution or other antibiotic droplets to prevent neonatal gonococcal ophthalmia.

Neisseria gonorrhoeae infection Complications prostatitis pelvic inflammatory disease endometritis

Complications include prostatitis, epididymis, spermatic inflammation, female cervicitis, pelvic inflammatory disease, endometritis, arthritis, etc.

Symptoms of Neisseria gonorrhoeae Common symptoms High heat of appetite lack of back pain, testicular tenderness, leucorrhea, increased abdominal pain, nausea, swallowing pain, urgency, frequent urination

The clinical manifestations caused by gonococcal infection depend on the degree of infection, the sensitivity of the body, the virulence of the bacteria, the length of the infection and the length of infection, as well as the health of the body, excessive sexual life, alcohol abuse, etc.

1. Primary infection refers to uncomplicated genitourinary gonorrhea.

(1) Male gonorrhea:

1 acute gonorrhea: incubation period of 1 to 14 days, often 2 to 5 days, manifested as acute urethritis symptoms, urethral redness, itching and slight tingling, followed by thin mucus outflow, causing urination discomfort, about 2 days later, The secretion becomes sticky, the urethra overflows, the pus is dark yellow or yellowish green, the redness develops to the glans of the penis and part of the urethra, frequent urination, urgency, dysuria, difficulty urinating, inconvenient movement, and frequent penis at night. Sexual erection, may have inguinal lymphadenopathy, redness and pain, but also suppuration, 50% to 70% of patients with gonococcal invasion of the posterior urethra, manifested as urinary distress, frequent urination, acute urinary retention, systemic symptoms are generally lighter, A few may have fever up to 38 ° C, general malaise, lack of appetite and so on.

2 Chronic gonorrhea: Symptoms last for more than 2 months, because the treatment is not thorough, Neisseria gonorrhoeae can be hidden in the urethra, paraurethral glands, urethral crypts make the course become chronic, such as patients with weak constitution, anemia, tuberculosis, illness At the beginning, it is chronic, mostly for the anterior and posterior urethra. It is good for invading the urethral bulb, membrane and prostate. It is often itch in the urethra. It has a burning sensation or mild tingling when urinating, and the urine flow is fine. Poor urination, dripping urine, most patients have a small amount of serous sputum sealing in the early morning urethra, if the common thin mucus overflows in the genital or penis root, the urine is basically clear, and the silk is visible.

(2) Female gonorrhea: The main part of female primary gonococcal infection is the cervix. Some patients have no symptoms, and the leucorrhea is increased. It is purulent or non-characteristic. It often has genital itching and burning sensation, accompanied by cervical congestion. Tenderness, occasional lower abdominal pain and low back pain, urethral orifice congestion, tenderness and purulent secretions, mild urinary frequency, urgency, dysuria, burning sensation during urination; gonococcal vaginitis is less common, mild symptoms Some patients have abdominal distension, low back pain, more vaginal discharge, and some patients have lower abdominal pain and menorrhagia.

2. Secondary infection

(1) Male gonorrhea comorbidities:

1 prostatitis: acute prostatitis has fever, chills, perineal pain and urinary tract infection symptoms such as urinary tract infection, examination of prostate swelling, tenderness, prostate massage smear or culture to find gonococcal, chronic prostatitis symptoms slightly, more There is only secretion in the urethra in the morning.

2 Epididymitis and seminal vesiculitis: unilaterally, with epididymal swelling, testicular tenderness, swelling, fever at the seminal vesiculitis, frequent urination, urgency, dysuria, terminal turbidity and blood, rectal examination can be touched Swelling seminal vesicles, accompanied by severe tenderness, chronic seminal vesiculitis generally no symptoms, rectal examination of the seminal vesicle hard, fibrosis.

3 urethral ball gland inflammation: occurs in the perineum or around, there are finger size nodules, pain, oppression of the urethra and dysuria, acute suppurative ulceration, may have fever and other systemic symptoms.

4 urethral stricture: repeated authors can cause urethral stricture, a small number of vas deferens or obstruction, dysuria, severe urinary retention, secondary vas deferens, seminal vesicle cyst and infertility.

(2) Female gonorrhea comorbidities: The main complication of female gonorrhea is gonococcal pelvic inflammatory disease, such as acute salpingitis, endometritis, secondary fallopian tube ovarian abscess and pelvic abscess caused by rupture, peritonitis, etc. Sudden onset after menstruation, high fever, chills, headache, nausea, vomiting, lower abdominal pain, increased purulent leucorrhea, thickening of bilateral attachments, tenderness.

3. Other parts of gonorrhea

(1) gonorrhea conjunctivitis: newborns often appear symptoms 2 to 3 days after birth, mostly bilateral, manifested as eyelid swelling, purulent secretions, adults mostly self-infection, often unilateral, the same performance Newborns, due to pus overflow, commonly known as "purulent eye", once delayed treatment, corneal perforation can lead to blindness.

(2) gonococcal pharyngitis: manifested as acute pharyngitis or acute tonsillitis, occasional fever and neck lymphadenopathy, throat dryness, sore throat, swallowing pain and other symptoms.

(3) gonococcal anal proctitis: manifested as urgency and heavy, with pus and blood, anal canal mucosal congestion, purulent secretion, gonococcal culture positive.

4. Disseminated gonococcal infection The disseminated gonococcal infection is due to the spread of gonococcal bacteria through the bloodstream to the whole body, resulting in more serious systemic infections, such as gonococcal sepsis, arthritis, endocarditis, meningitis and so on.

Examination of gonococcal infection

Including smear examination, culture examination, drug sensitivity test and penicillinase-producing gonococcal (PPNG) determination, antigen detection, genetic diagnosis.

1. Smear examination Take the patient's urethral secretions or cervical secretions for Gram staining, find Gram-negative diplococcus in polymorphonuclear leukocytes, and there are many bacteria in female cervical secretions, and the sensitivity and specificity are poor. The positive rate is only 50% to 60%, and there is a false positive. Therefore, the World Health Organization recommends using a culture method to examine female patients. Chronic gonorrhea has a low positive rate due to less gonococcal secretions. Therefore, it is necessary to take a prostate massage solution. Increase the detection rate, pharyngeal smear found that Gram-negative diplococcus can not diagnose gonorrhea, because other Neisseria species are normal in the pharynx, and the smear positive for the symptoms should be further examined.

2. Culture examination of gonococcal culture is an important evidence for diagnosis. The culture method is a sensitive method for males with mild or asymptomatic symptoms. As long as the culture is positive, the diagnosis can be confirmed. Before the genetic diagnosis is made, the culture is the world. The only method recommended by WHO for screening gonorrhea. Currently, the recommended medium for selection is modified Thayer-Martin (TM) medium and New York City (NYC) medium. Domestic chocolate agar or blood agar medium is used. , optionally inhibiting the growth of many other bacteria, cultured at 36 ° C, 70% humidity, containing 5% to 10% carbon dioxide (candle) environment, 24-48 hours observation, colony morphology after cultivation, Gram staining The oxidase test and the sugar fermentation test were identified, and the positive rate of culture was 80% to 95% for males and 80% to 90% for females.

3. Antigen detection

(1) Solid phase enzyme immunoassay (EIA): can be used to detect gonococcal antigens in clinical specimens.

(2) Direct immunofluorescence assay: Neisseria gonorrhoeae outer membrane protein-1 was directly detected by fluorescently labeled monoclonal antibody.

4. Genetic diagnosis

(1) Gene probe diagnosis: Gene probe diagnosis of Neisseria gonorrhoeae uses probes such as plasmid DNA probes, chromosomal gene probes and rRNA gene probes, and the sensitivity of gene probe diagnosis is poor.

(2) Gene amplification detection: The emergence of PCR technology further improves the sensitivity of gonococcal detection. It has the advantages of rapid, sensitive, specific and simple. It can directly detect a very small number of pathogens in clinical specimens, and prevent contamination during operation. In order to avoid false positives.

5. The drug sensitivity test is further tested for drug susceptibility after positive culture, using a paper diffusion method for sensitivity test, or agar plate dilution method for determining minimum inhibitory concentration (MIC) to guide the selection of antibiotics.

6. PPNG detection of -lactamase, using paper acidity quantitative method, using Whatman I filter paper PPNG strain can make its color from blue to yellow, positive for P-PPNG, negative for N-PPNG.

In patients with mild myocarditis, ECG shows conduction block.

Diagnosis and identification of gonococcal infection

diagnosis

The diagnosis must be determined based on a history of exposure, clinical performance, and laboratory tests.

1. Patients with contact history have extramarital sex or history, spouse has a history of infection, and close contact with gonorrhea patients (especially gonorrhea patients at home), newborn mothers have a history of gonorrhea.

2. Clinical manifestations of the main symptoms of gonorrhea are frequent urination, urgency, dysuria, urethra, cervix or vaginal opening with purulent secretions, or gonococcal conjunctivitis, enteritis, pharyngitis, etc., or dissemination Gonorrhea symptoms.

3. Laboratory examination of male acute gonorrhea urethritis smear examination has a preliminary diagnostic significance, for women only for reference, should be cultured to confirm gonococcal infection, where conditions can be diagnosed by genetic diagnosis.

Differential diagnosis

The disease should be differentiated from urethritis, conjunctivitis, enteritis and pharyngitis caused by other bacterial infections.

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