Trichomoniasis

　　1. Etiology

　　Trichomonas vaginalis, the causative agent of trichomoniasis, was first discovered in female vaginal secretions by Donne (1836) and named trichomonas-vaginalis the following year. This protozoan, like Trichomonas tenax and Trichomonas oralis, has only trophozoites and no cyst stage. The fresh specimens of vaginal secretions or culture media vary in shape and size depending on the source of the protozoan, the osmotic pressure of the culture medium, and the division of the trophozoites. The typical shape is pear-shaped or oval, with a size of 9.7 (4.5-19) μm × 7 (2.5-12.5) μm. The cytoplasm is uniform, smooth, and transparent, propelled forward by the movement of the four flagella at the anterior end and by the undulating membrane performing spiral movement. Trichomonas vaginalis can also form pseudopodia for feeding or attachment. The axostyle runs through the body and exits at the end. After hematoxylin or Giemsa staining, the anterior end of the body shows five ring-shaped kinetosomes arranged in a circle, from which four anterior flagella and one posterior flagellum emanate. The undulating membrane and the basal rod also originate from the kinetosome, with a circular or pear-shaped cell membrane and cytoplasm extending outward as a wavy membrane structure, the outer edge of which is free. After the posterior flagellum is emitted, it attaches to the outer edge of the undulating membrane and extends backward, coinciding with the start and end of the undulating membrane, but without any structural connection between the two. One-third of the anterior part of the body contains an oval nucleus with a double nuclear membrane and nuclear pores. The nucleoplasm consists of fine granules, containing 6-8 electron-dense chromatin granules of similar size and a nucleolus. The nuclear membrane is surrounded by endoplasmic reticulum and connected to the nuclear pores by microtubules. There are accessory bodies and accessory fibers near the nucleus. Under the electron microscope, there are five kinetosomes arranged in a ring-like formation at the anterior part of the body, forming the centriole, which is surrounded by a double-membrane sheath to form the centriole apparatus. The four anterior flagella are emitted from the first, third, fourth, and fifth kinetosomes, while the second kinetosome emits one posterior flagellum and a basal rod. The accessory fibers are attached to the base of the third kinetosome and extend backward to the nuclear level. The axostyle is a double-membrane transparent cylinder structure, divided into the axoneme, shaft, and tail into three parts.

　　In addition, the nematode's body contains spherical and elliptical food vacuoles, empty vacuoles, and dense particles of varying sizes. The nematode also has an independent, fully developed Golgi complex. Trichomonas vaginalis reproduces by binary fission or multiple fission. In vaginal secretions or culture media, the nematode can reproduce by multiple fission, with a single nematode potentially dividing into up to 16. The nematode primarily absorbs nutrients by osmosis, therefore, nematodes in fresh vaginal secretions often lack food vacuoles, and there are almost no bacteria in the cytoplasm. The nematode can also engulf solid food adhering to its surface by means of pseudopodia. Trichomonas vaginalis can utilize glucose and its polymers, with maltose being more beneficial for the growth of the nematode. The nematode can also utilize serum, peptone, and digested casein. In addition, ribonucleic acid, vitamin C, complex vitamin B, pantothenic acid, and phosphorus are all necessary components for promoting the growth of the nematode. Trichomonas vaginalis grows and reproduces between 25～42℃ but is most suitable at 32～35℃. It can survive for 120～150 hours at room temperature (22～25℃), but it dies in 4 minutes at 50℃ and in 1 minute at -70℃. The optimal pH for the growth of Trichomonas vaginalis is 5.2～6.6, slightly acidic substances are favorable for the reproduction of the nematode, but pH below 5.0 or pH 7.5 will also inhibit or kill the nematode. This nematode is a facultative anaerobic parasite, adapted to parasitize in relatively anaerobic vaginas and can reproduce rapidly, so it mainly parasitizes in the vagina, but can also parasitize in the urethra, uterus, paraurethral glands, and bladder. In the male urogenital system, the prostate is the most common site, and it can also parasitize in the epididymis or prepuce.

　　2, Pathogenesis

　　The pathogenicity of Trichomonas vaginitis is closely related to the virulence of the strain, the physiological condition of the host, the distribution of bacteria in the vaginal flora, etc. The virulence of the strain isolated from acute and subacute Trichomonas vaginitis patients is generally stronger than that of chronic cases, and it can form a large abscess under the skin of mice, and has a strong ability to dissolve red blood cells. The decline of the ovarian function of the host directly affects the thickness of the vaginal mucosa, making the vaginal mucosa thin and fragile with small hemorrhagic spots; the reduction of glycogen inhibits the survival of lactobacilli in the vagina, affecting lactate production, causing the vagina to tend towards neutral or alkaline from acidic, and other bacteria to proliferate extensively, reducing the cleanliness of the vagina and promoting the parasitic onset of Trichomonas vaginitis. The vaginal pH after menstruation is close to neutral, rich in serum components, which is conducive to the reproduction of the parasite, so the infection rate and incidence rate of pregnant and postmenopausal women are relatively high. In addition, fatigue, colds, intestinal dysfunction, and other factors can all reduce the body's resistance and cause the onset of the disease. Trichomonas vaginitis can ingest sperm and produce a large amount of vaginal discharge, which can hinder sperm survival, and some scholars believe that it can cause infertility. The prepuce, vaginal mucosa, and cervix may become congested and edematous or have scattered hemorrhagic spots. The vaginal wall, especially the posterior fornix, has red granules that protrude, known as 'strawberry-like spots', which are caused by the dilation of blood vessels in the inflamed area. Under the microscope, the vaginal mucosa is covered with a layer of coagulated material, containing Trichomonas vaginitis, leukocytes, and red blood cells. The bodies do not invade intact epithelial cells, so the vaginal epithelial cells are generally intact. However, due to the migration of the bodies between cells, some cell edges show erosion, and hemorrhagic spots may be visible on the epithelial cells. The subepidermal layer has infiltration of lymphocytes and plasma cells, and there are also obvious necrotic areas, which can spread to the surface. The bodies are often found in the necrotic lesions.

　　Common complications of Trichomonas vaginitis: Occasionally, in severe cases of female Trichomonas infection, ascending infection can lead to cystitis, pyelonephritis, and concurrent urinary retention. Trichomonas vaginitis can ingest sperm, leading to infertility. Cystitis: There is a burning sensation during urination, and pain in the urethral area. Sometimes there is urgency and severe frequency of urination. Gross hematuria is common, and there are occasional visible hematuria and blood clots. Patients may feel weak and tired, have low fever, and may also have high fever, as well as discomfort over the pubic symphysis and back pain.

　　After a female is infected with Trichomonas vaginitis, there is generally a latent period of 4-28 days, mainly manifested by a large amount of smelly purulent vaginal discharge, which is foamy in nature. In severe cases, the leukorrhea may contain blood. Most patients have vulvar itching and burning sensation, difficulty in urination, pain, frequent urination, urgency, and even intermittent hematuria. Symptoms often worsen before and after menstruation, during pregnancy, fatigue, or after sexual intercourse. Examination may reveal vulvar inflammation, erosion, labial edema, vaginal and cervical mucosal erythema and urethritis, occasionally with inguinal erosion, etc. In severe cases, there may be hemorrhagic spots and erosion on the vaginal wall and cervix, presenting a typical 'plum blossom' appearance, and the cervix may become congested and edematous.

　　The male urethra is also a major site of Trichomonas infection, with asymptomatic cases accounting for 50-90%. Those who cause urethritis may present with dysuria, frequent urination, and 50-60% have an increase in urethral secretion, which is purulent or mucous, with a small amount, only a drop at the urethral orifice in the morning, which disappears after urination. The secretion is often intermittent, sometimes present and sometimes not, thus it is not easily noticed by patients and does not receive timely treatment.

　　The incubation period is generally not clear, and volunteer inoculation tests can show symptoms within 4-7 days.

　　The main symptoms are increased yellow-green frothy leukorrhea and vulvar itching. The leukorrhea is thin and has a foul smell. If there is a secondary bacterial infection, the leukorrhea may become purulent with an odor. When the vaginal mucosa bleeds, it often presents as metrorrhagia. The amount of leukorrhea is often large, often accumulating in the posterior fornix, and sometimes it can overflow from the vaginal orifice. The itchy area is mainly around the vaginal orifice and vulva, with burning pain, and sexual intercourse pain is also common. Vaginal examination may show redness and swelling of the vaginal mucosa and cervix,

　　2. Male Trichomoniasis Infection:Male patients show mild symptoms, which may include varying degrees of urethral itching and discomfort, which worsens during urination. Difficulty in urination may occur, with reddened urethra and the discharge of yellowish-white purulent secretion. In severe cases, post-urethral inflammation and cystitis may occur.

　　Most people do not show clinical symptoms after infection with this worm and are called asymptomatic carriers. These carriers are both sources of infection and can become ill under favorable conditions. Treatment should also be given to these carriers.

　　Trichomoniasis with typical symptoms is not difficult to diagnose. Typical symptoms can serve as the basis for clinical diagnosis, and diagnosis can be made even if trichomonads are not found. For atypical patients and carriers, reliance should be placed on the examination of trichomonads as the basis for confirmation. Clinically, the drop method is commonly used, placing a drop of warm saline on a slide, taking a small amount of vaginal secretion and mixing it with the salt water, and immediately examining under a microscope. If attention is paid to keeping warm, fresh, and the examiner has rich experience, the detection rate and reliability are very high. In recent years, monoclonal antibodies against Trichomonas vaginalis have been prepared, and indirect fluorescent antibody test (IFA) is used to check for trichomonads in vaginal secretions, which has improved the positive rate and accuracy. The above methods can also be used to check for trichomonads in prostatic fluid, seminal fluid, and urinary sediment in male patients and carriers, but the positive rate is much lower than in females. Trichomoniasis vaginitis should be differentiated from fungal vaginitis, gonococcal vaginitis, and senile vaginitis. In addition, non-specific bacterial vaginitis is often confused with trichomoniasis vaginitis complicated by bacterial infection, and should also be considered in clinical diagnosis.

　　Trichomoniasis is a parasitic disease mainly transmitted through sexual contact, which is infectious. 70% of cases are asymptomatic, making diagnosis difficult. Women may experience discomfort for a week or several months, which may significantly improve due to menstruation or pregnancy. If left untreated, the parasites can infect the urinary and reproductive systems. In women, susceptible areas include the vagina, urethra, cervix, bladder, and other glands. In men, it may affect the urethra, prostate, seminal vesicle, and epididymis. Trichomonas thrives in alkaline environments. The incidence rate increases when women use oral contraceptives, are pregnant, or use general douches, as these practices can increase the alkalinity of the body's prognosis:

　　The disease can be cured after clinical treatment, with a good prognosis.

　　1. Hanging drop method

　　The hanging drop method is the simplest way to check for Trichomonas vaginalis, with a positive rate of 80%-90%. Apply the sample to a slide, add one drop of physiological saline, cover with a coverslip, and examine under a 100-200x lens. The flagella of the protozoa can be seen to be moving, and adding 5% neutral red to the physiological saline will prevent the trichomonads from dying and coloring, leaving a pink surrounding, making it easier to identify the white protozoa. Alternatively, a drop of 1600x acridine orange solution can be added to the fresh sample and observed under a fluorescence microscope, where the organism will exhibit a pale yellow-green fluorescence, which is particularly beautiful. Direct microscopic examination has a very high detection rate.

　　2. Smear staining method

　　If the pH value of vaginal secretions is greater than 5.0, active trichomonads can be seen under wet mount microscopy.

　　Apply the secretion to a glass slide, wait for it to dry naturally, and then stain it with different stains such as Gram stain, Wright stain, Giemsa stain, PAS stain, and Leishman stain. This method not only allows you to see the shape and content of the trichomonads but also enables you to observe other microorganisms present in the vagina. Acridine orange staining and fluorescence microscopy can also be used.

　　3. Culture method

　　Add vaginal or urethral secretions to the culture medium, incubate at 37℃ for 48 hours, and inoculate once every 72 hours. Take one drop of the mixed culture solution and make a smear, then stain and examine under a microscope.

　　4. Immunological methods

　　The detection of specific antigens of Trichomonas vaginalis can be done using common immunological methods such as fluorescence antibody testing, ELISA, and latex agglutination, which have a higher positive rate than smear methods, but are generally not used in clinical practice.

　　1. Opt for foods with antibacterial properties, such as garlic, onions, purslane, houttuynia, linden leaves, and chrysanthemum brain. The diet should be light and nutritious.

　　2. Abstain from seafood and other irritants. Seafood irritants such as shrimp, crab, and shellfish can exacerbate itching. Fish such as hairtail, shrimp, and crab, which have a strong smell, can promote damp-heat, causing increased vulvar itching after consumption, which is not conducive to the regression of inflammation. Patients with trichomoniasis vaginitis should avoid eating these foods as much as possible.

　　3. Avoid smoking and drinking, as well as hot and spicy foods such as mutton. Avoid fatty, sweet, greasy, fried, spicy foods such as chili, ginger, scallion, garlic, seafood, and beef. Avoid tonifying the body.

　　4. Foods should be light in taste, such as glutinous rice, sticky rice, yam, dolichos, lotus seed, lily, jujube, longan meat, chestnut, black sesame, black soybean, walnut kernel, and egg to supplement the body's nutritional needs.

　　5. Eat more foods rich in vitamin B: such as wheat, sorghum, coix seed, honey, tofu, chicken, chive, milk, etc.; eat more fruits and fresh vegetables.

　　6. Avoid sweet and greasy foods: foods such as lard, butter, and beef fat, and high-sugar foods such as chocolate and sweet pastries, which have the effect of increasing dampness and heat, can increase the secretion of leukorrhea and affect the treatment effect.

　　There are many causes of trichomoniasis vaginitis. Once trichomoniasis vaginitis occurs, it is necessary to go to the hospital to identify the cause and receive active treatment. Generally speaking, trichomoniasis vaginitis can be cured after symptomatic treatment.

　　First, traditional Chinese medicine

　　1. Funing suppository:Clear heat and drain dampness to stop leukorrhea. For external use, clean the vagina before going to bed every night, insert one suppository deeply into the vagina, and use one every other day, with a course of 7 days.

　　2. Paper anti-itching agent:Medicinal toilet paper, for external use. Apply one sheet per day on the underwear. Avoid spicy foods when using.

　　Second, Western treatment methods for trichomoniasis vaginitis

　　Principles of treatment:All patients with positive trichomonas examination, regardless of symptoms, should receive treatment. It is divided into local and systemic medication. Regardless of the type of treatment, the spouse and family members of the patient should also be treated simultaneously.

　　Curative criteria:Clinical symptoms improve, such as the disappearance of vulvar irritation symptoms, normal vaginal discharge, and the conversion of trichomonads to negative in laboratory tests.

　　1. Local treatment

　　(1) Vaginal irrigation. Use 0.5% to 1% lactic acid or acetic acid; for those with concurrent bacterial infection, 1:2000 new purification solution can be used for irrigation.

　　(2) Inserted into the posterior fornix of the vagina.

　　① Metronidazole vaginal effervescent tablets (each containing 200mg) or acetarsol tablets [each containing 0.25g acetarsol (acetarsol), 0.03g boric acid] one tablet, once daily or every other day, with a course of 7-10 times, and 2-3 courses consecutively.

　　② Shuangzao Tai suppositories (containing 200mg metronidazole, 8mg chlorhexidine acetate, and 160mg clotrimazole) one, used every night, for 7 days as a course, and 1-2 courses consecutively, with a total effective rate of up to 96.24%.

　　③ Dripping vitamin tablets, one tablet per day placed in the fornix of the vagina, with a course of 10 days.

　　④ Carbarsone tablets, 0.2-0.4 grams placed in the posterior fornix of the vagina, once daily, with a course of 7-10 days.

　　⑤ Troglitazone, 100,000 units inserted into the vagina daily, with a course of 10 days.

　　Local treatment can effectively control local symptoms, but it cannot completely kill the parasites, and it is prone to recurrence after discontinuation of medication.

　　2. General treatment:Indicated for all patients with Trichomonas vaginalis infection, male urogenital tract trichomoniasis, and carriers.

　　Metronidazole: Due to its potential mutagenicity, metronidazole is contraindicated in pregnant and lactating women.

　　Usage and Dosage:

　　200-250mg per time, 3 times/d, for 7-10 days as a course of treatment. Or use a high-dose therapy of taking metronidazole 2g at one time.

　　After the treatment is negative, the treatment should continue for 1-2 courses. If the failure to take 2g at one time, the 7-10 day regimen can be changed, or the dose of the 7-10 day regimen can be increased to 400-500mg per time. If the 7-10 day regimen fails first, the dose can still be increased to continue treatment.

　　Other drugs such as piperidazole also have inhibitory and killing effects on Trichomonas vaginalis, 0.1g per time. 3 times/d, oral, for 7-10 days as a course of treatment, be cautious in patients with abnormal liver function, and some patients may experience side effects such as purpura, decreased white blood cells and platelets, etc.

　　3. Treatment for pregnant women:Metronidazole can be used in pregnant and lactating women. Pregnant women with symptoms should be treated to alleviate symptoms. Although existing data indicate that metronidazole has no teratogenic effect, it should be used with caution in the first three months of pregnancy. Local treatment in the early stages of pregnancy can relieve symptoms, such as clotrimazole suppository 100mg, vaginal application, 1 time/d, for 7 days. The oral dose of metronidazole 2g during lactation should be interrupted for 24 hours.

　　4. Treatment for treatment failure or recurrence

　　Patients with treatment failure or recurrence can be treated by increasing the dose of metronidazole or switching to tinidazole:

　　(1) Metronidazole 500mg, oral, 3 times/d, for 7 days. At the same time, apply metronidazole suppository 500mg vaginally, 1 time/d, for 7 days;

　　(2) Metronidazole 2g, oral, 1 time/d, for 3-5 days;

　　(3) Tinidazole 400-500mg, oral, 2 times/d, for 7 days.

　　5. Precautions

　　Avoid sexual intercourse during treatment, wash the vulva frequently, change underwear frequently, and check and treat both partners at the same time if necessary. For those who have recurrent episodes, after one cure, apply local vaginal medication 1-2 times after each menstrual period is clean, for a continuous period of 3 months to consolidate the efficacy.