Trichomoniasis vaginalis

Introduction to vaginal trichomoniasis Trichomonas vaginalis is one of the most common sexually transmitted diseases caused by Trichomonas vaginalis, mainly invading women's vagina, and can also cause male urinary tract infections due to sexual intercourse. The infection rate of vaginal trichomoniasis in adult women can be as high as 95%. basic knowledge The proportion of the disease: the incidence rate of women is over 80% Susceptible people: women Mode of transmission: sexual intercourse. Complications: urethritis cystitis urinary retention infertility

Causes of vaginal trichomoniasis

(1) Causes of the disease

Trichomonas vaginalis Trichomonas vaginalis was first discovered by Donne (1836) in women's vaginal secretions, and the next year was named trichomonas vaginalis. This worm is the same as Trichomonas vaginalis and trichomoniasis. Fresh specimens of the sac, vaginal secretions or culture medium, the shape and size vary with the source of the species, the osmotic pressure of the medium and the division of the worm, typically pear-shaped or oval, 9.7 (4.5 19) m × 7 (2.5 ~ 12.5) m, the cytoplasm is uniform and smooth, transparent, with the front four flagella swinging forward, and spiral motion of the wave motion, vaginal trichomoniasis can also form pseudopod, for feeding For food or attachment, the shaft column runs through the worm body and passes through the end. After staining with hematoxylin or Giemsa, five hair matrixes arranged in a ring shape are visible at the front end of the worm body, and four anterior flagella and one hair are emitted from the hair matrix. The posterior flagella, the undulating membrane and the base staining rod are also emitted from the hairy matrix. The round or pear-shaped corpuscular cell membrane and cytoplasm extend to a wavy membrane structure in vitro. The outer edge is free, and the posterior flagella is attached to the fluctuation. Outer edge of the membrane and extending backwards, with a wave film Consistent, but there is no organizational relationship between the two, the first 1/3 of the worm has an elliptical nucleus, the nuclear membrane is double-layered and has nuclear pores, the nucleus is fine particles, and there are 6-8 similar sizes. Electron-density chromatin particles and a nucleolus. The outer membrane of the nuclear membrane has an endoplasmic reticulum and has microtubules communicating with the nucleus. There are sub-matrix and sub-base fibers near the nucleus. There are five hair bases under the electron microscope. The front part is arranged in a ring shape to form a central body, and the outer part is surrounded by a sheath of a double-layer membrane to form a central body device. The four front flagella are respectively emitted from the first, third, fourth, and fifth hair bases, and the second hair base body is issued. After the flagella and the base dyeing rod, the secondary fiber is attached to the base of the third base and extends backward to the core level. The shaft column is a double-layer transparent cylindrical structure, a split head, a dry head and a tail.

In addition, there are round and elliptical food bubbles, vacuoles and dense granules of different sizes. The worm also has an independent fully developed Golgi complex. Trichomonas vaginalis proliferates by two divisions or multiple divisions. In vaginal secretions or culture medium, the worm body can proliferate by multiple division methods, and one worm body can be divided into up to 16 pieces. The worm body mainly absorbs nutrients through the infiltration method, so there is no food bubble in the vaginal body secreted by the fresh vaginal. There is almost no bacteria in the cytoplasm. The worms can also rely on the pseudo-foot to swallow the solid food adhering to the surface. The vaginal trichomoniasis can use glucose and its aggregates. Among them, maltose is more conducive to the growth of the worms. Serum, peptone and digested casein can be used. In addition, ribonucleic acid, vitamin C, multivitamin B, pantothenic acid and phosphoric acid are essential components for promoting the growth of worms. Trichomonas vaginalis grows between 25 and 42 ° C, but It is most suitable at 3235°C. It can survive for 120150h at room temperature (2225°C), but it will die at 50°C for 4min, die at -70°C for 1min, and the optimal pH for growth of Trichomonas vaginalis is 5.26.6. Slightly acidic transmitters are conducive to the propagation of worms, but below pH 5. O or pH 7.5 will also inhibit or kill the worms, the genus is a facultative anaerobic parasite, adapted to parasitism in the relatively hypoxic vagina and It can rapidly multiply, so the insect mainly parasitizes in the vagina, but it can also be parasitic in the urethra, uterus, paraurethral gland and bladder. In the male genitourinary system, the prostate is the most common, and it can also be parasitic in the epididymis or the foreskin sac.

(two) pathogenesis

The virulence of Trichomonas vaginalis is closely related to the virulence of the strain, the physiological state of the host, the distribution of bacterial flora in the vagina, etc. The virulence of the strains isolated from acute and subacute vaginal trichomoniasis is generally stronger than that of chronic diseases. In the case of the worm, a large abscess can be formed under the skin of the mouse, and the ability to dissolve red blood cells is also strong. The ovarian function of the host directly affects the thickness of the vaginal mucosa, making the vaginal mucosa thin and brittle and having small bleeding points; Lactobacillus survival inhibition affects lactic acid production, vaginal acid tends to be neutral or alkaline, other bacteria multiply, vaginal cleanliness declines to promote parasitic vaginal vaginal, vaginal pH near neutral after menstruation, rich in serum components Insect reproduction, so the infection rate and incidence rate of pregnant women and menstruation are higher. In addition, fatigue, cold, intestinal dysfunction, etc. can cause the body's resistance to decrease and cause disease. Trichomonas vaginalis can swallow sperm and in the vagina. The production of a large number of secretions can prevent sperm survival, so some scholars believe that can cause infertility, vaginal vestibule, vaginal mucosa and cervical filling Edema or scattered at the bleeding point, the vaginal wall, especially the posterior fornix has red small particle protrusions, called "strawberry-like spots", which is caused by vasodilation of the inflammation site. The vaginal mucosa under the microscope is covered with a layer of coagulating substance containing vaginal hair drops. Insects, white blood cells and red blood cells, the worms do not invade intact epithelial cells, so vaginal epithelial cells are generally intact, but because the worms migrate between cells, some cell edges are corroded, and bleeding spots are sometimes seen on epithelial cells. In the lower layer, lymphocytes and plasma cells are infiltrated. Here, obvious necrotic areas can be seen and spread to the surface. In the necrotic lesions, the worms can often be found.

Prevention of vaginal trichomoniasis

1. Strengthen health education and carry out census and general work.

2. Do a good job in health protection. Eliminate the source of infection, strictly manage the system, prohibit patients from entering the swimming pool, improve public health equipment, and disinfect the medical units to prevent cross-infection.

3. Go to a regular hospital for treatment.

4. Actively treat patients and those with insects, and regularly check female workers and female students living in groups to improve public health facilities in factories and schools.

5. For stubborn recurrence cases, it is advisable to perform trichomoniasis examination of the man's urine or prostatic fluid for simultaneous treatment and control of recurrence.

6. Female condoms also have a good preventive effect.

Complications of vaginal trichomoniasis Complications urethritis cystitis urinary retention infertility

Male Trichomonas infection, severe urethritis, cystitis, occasional serious infection of Trichomonas vaginalis can cause cystitis, pyelitis complicated by urinary retention, etc., Trichomonas vaginalis can swallow sperm, can cause infertility .

Symptoms of vaginal trichomoniasis common symptoms vaginal discharge increased bacterial infection itching urinary frequency vaginal discharge increased inflammation lumbosacral soreness urethra itching urgency urinary pain

After female vaginal infection with Trichomonas, it usually takes 4-28 days of incubation period, mainly showing a large number of odorous purulent vaginal secretions. The secretions are foamy. In severe cases, vaginal discharge can be mixed with blood. Most patients have genital itching and burning. Feeling, dysuria, pain, frequent urination, urgency, and even intermittent hematuria, symptoms often worsen before and after menstruation, pregnancy, fatigue or post-hospital aggravation, examination can be found in vulvar inflammation, erosion, labia edema, vaginal and cervical mucosa redness and Urethritis, occasionally groin rubbing, etc., severe vaginal wall and cervix have bleeding points and erosion, showing a typical "yangmei", the cervix can be congested, edema.

Male urethra is also the main place to infect trichomoniasis, asymptomatic accounted for 50-90%, causing urethritis manifested as dysuria, frequent urination, 50-60% of urethral secretion increased, purulent or mucinous secretions, amount Rarely, there is only a small droplet at the urethral opening in the morning, disappearing after urination, and the secretions are often intermittent, sometimes absent, and thus do not cause the patient's attention, and can not get the ultimate treatment.

The incubation period is generally unclear. Volunteer vaccination tests can occur after 4 to 7 days.

1. The main symptoms of female trichomoniasis are yellow-green foam vaginal discharge increased and genital itching, leucorrhea thin and odor, if combined with bacterial infection, it is a purulent vaginal discharge with odor, vaginal mucosal bleeding often with red bands, leucorrhea a lot It often accumulates in the posterior iliac crest, and sometimes it can also overflow the vaginal opening. The itching area is mainly in the vaginal opening and vulva. Burning pain and sexual pain are also common. Vaginal examination shows vaginal mucosa and cervical redness, bleeding "strawberry-like spots", vaginal touch Pain, etc., a small number of patients may have lumbosacral pain and irregular menstruation, vaginal trichomoniasis such as parasitic in the urethra and bladder can produce trichomoniasis urethritis, patients with frequent urination, urgency, dysuria, intermittent hematuria, Broken urinary line, urinary retention and redness of the urethra.

2. male trichomoniasis infection in male patients with mild performance, may have varying degrees of urethral itching and discomfort, increased urination, dysuria, urethral flushing and yellowish white purulent secretion, severe urethra Inflammation, cystitis.

Most people do not have clinical symptoms after infection with the worm. They are called asymptomatic worms. This worm is both a source of infection and can occur when conditions are appropriate. The worms should also be treated.

It is not difficult to diagnose vaginal trichomoniasis with typical symptoms. Typical symptoms can be used as a basis for clinical diagnosis. Even if trichomoniasis is not found, it can be diagnosed. For atypical patients and worms, it should be confirmed by checking trichomoniasis. According to the clinical use of hanging drop method, put a drop of warm physiological saline on the slide, take a little vaginal secretion mixed in saline, and immediately microscopic examination, this method can pay attention to heat preservation, fresh, the examiner has rich experience, its inspection The rate and reliability are very high. In recent years, monoclonal antibodies against Trichomonas vaginalis have been prepared. Indirect fluorescent antibody test (IFA) has been used to detect trichomoniasis in vaginal secretions, and the positive rate and accuracy have been improved. Insects can also use the above methods to check the prostatic fluid, semen and urine sediment, but the positive rate is much lower than that of women. Trichomonas vaginitis should be associated with fungal vaginitis, gonococcal vaginitis and senile vaginal Inflammation, in addition, non-specific bacterial vaginosis is often confused with trichomonas vaginitis with bacterial infection, and should be considered in clinical diagnosis.

Examination of vaginal trichomoniasis

First, hanging drop method

Hanging drop method is the simplest method to check Trichomonas vaginalis. The positive rate can reach 80%-90%. Apply the sample to the slide, add 1 drop of normal saline, add cover slip, and use 100-200 mirror. Inspection, visible protozoal flagellar fluctuation membrane activity, adding 5% neutral red in physiological saline, trichomoniasis can not die, does not color, and the formation of pink around, easy to recognize the white protozoa, or use 1600 times acridine One drop of orange liquid was dropped into the fresh specimen and observed with a fluorescence microscope. The worm body showed a yellowish-green fluorescence, which was particularly good. The detection rate of direct microscopic examination was extremely high.

Second, smear staining

The pH of the vaginal secretions was >5.0, and the active trichomoniasis was observed on the wet sheet microscopy.

The secretions are applied to the slides and can be dyed with different dyes after natural drying, such as Gram staining, Reiter staining, Giemsa staining, PAS staining and Leishman staining. This method can not only see the trichomoniasis. Shape and content, and can see other microorganisms in the vagina at the same time, can also be stained with acridine orange, fluorescence microscopy.

Third, the training method

The vaginal secretions or urethral secretions were added to the culture medium, cultured in a 37 ° C incubator for 48 hours, inoculated once every 72 hours, and one smear of the culture mixture was taken and stained for microscopy.

Fourth, immunological methods

The specific antigens of Trichomonas vaginalis are detected. The commonly used immunological methods include fluorescent antibody test, ELISA method, latex agglutination method, etc. The positive rate is higher than that of the smear method, but the clinical examination is generally not carried out by immunological methods.

Diagnosis and identification of vaginal trichomoniasis

diagnosis

1. vaginal trichomoniasis: 1 vaginal secretion increased foamy; 2 cervix vaginal wall showed a characteristic strawberry-like appearance, trichomoniasis positive.

2. Male trichomonas non-gonococcal urethritis: 1 mild edema of the urethra, and a small amount of mucus, purulent or bloody secretions. 2 may have cystitis or pyelonephritis. 3 trichomoniasis test positive.

Differential diagnosis

The disease must be differentiated from other pathogens of the vagina, such as Candida, Neisseria gonorrhoeae, Corynebacterium vaginalis and other infectious vaginitis.

1. Bacterial vaginosis vaginal secretions often accompanied by fish-like odor and pH> 4.5, similar to trichomoniasis, but patients with bacterial vaginosis generally have no vulvar irritation, vaginal congestion, secretions are thin and uniform Gray-white, not yellow-green foam-like, positive for amine test, positive for microscopic examination.

2. Rosary vaginitis often has genital itching and (or) irritation, check vulvitis, vaginal mucosa flushing, vaginal secretions like cheese-like clots or bean dregs, pH <4.5, amine test negative, visible under the microscope Pseudohyphae and blast spores.

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