I. Etiology: Trichomonas vaginalis, a common vaginitis, is caused by Trichomonas vaginalis. The suitable temperature for trichomonas growth is 25°C to 40°C and pH 5.2 to 6.6 in a humid environment. The life history of Trichomonas is simple, with only trophozoites and no encapsulation period. The trophozoites are strong and can survive for 21 days at 3°C to 5°C, 20-60 minutes at 46°C, and about 10 hours in a semi-dry environment; they can also survive for 45-120 minutes in ordinary soapy water. It does not grow in environments with pH below 5.0 or above 7.5. The vaginal pH of trichomonas vaginalis patients is usually 5-6.6, mostly >6.0. The vaginal pH changes before and after menstruation and approaches neutrality afterwards, so the trichomonas hidden in the glands and vaginal folds often multiply before and after menstruation, causing inflammatory episodes. It consumes or engulfs glycogen in the vaginal epithelium and prevents the production of lactic acid. Trichomonas is not only parasitic in the vagina, but also in the urethra or paraurethral glands, and even in the bladder and renal pelvis, as well as in the male partner’s foreskin folds, urethra or prostate. Mode of infection: 1. Direct transmission through sexual intercourse; 2. Indirect transmission through public baths, bath tubs, bath towels, swimming pools, bidets, clothing, etc.; 3. Medical transmission: transmission through contaminated instruments and dressings. Clinical manifestations: The incubation period is 4 to 28 days. The main symptoms of trichomonas vaginalis are increased thin foamy leucorrhea and itchy vulva, if there is a mixture of other bacteria, the discharge is purulent and may have an odor. Itching is mainly at the vaginal opening and vulva, with occasional burning, pain, and painful intercourse. Trichomonas vaginalis can swallow sperm and prevent lactic acid production, which can affect the survival of sperm in the vagina and cause infertility. If there is infection in the urethra, there may be frequent and painful urination, and sometimes hematuria is seen. On examination, the vaginal mucosa is congested, and in severe cases there are scattered bleeding spots. The posterior curvilinear ronge has a large amount of leucorrhea, which is a thin grayish yellow, yellowish white liquid or yellowish green purulent discharge, often frothy. The vaginal mucosa is often not abnormally changed in those with worms. Typical cases are easily diagnosed if trichomonas is found in the vaginal secretions. The easiest way to check for trichomonas is the suspension method. In symptomatic patients, the positivity rate can be 80-90%. To do this, add a small drop of warm saline to a slide, take a small amount of discharge from the back of the vagina, mix it with the saline and immediately look for trichomonads under a low magnification light microscope. If trichomonas is present, it can be seen to move in a wave-like motion and the surrounding leukocytes can be seen to be pushed. In suspicious patients, if trichomonas is not found by repeated suspension, it can be sent for culture with an accuracy of about 98%. Avoid sexual intercourse, vaginal irrigation or local medication 24 to 48 hours before taking out the secretion. After taking out the secretion, send it for examination and pay attention to keep it warm, otherwise the activity of trichomonas will be weakened, which will make identification difficult. V. Prevention To make good health propaganda, actively carry out census and universal treatment work to eliminate the source of infection. Strict management system, trichomonas patients or those with worms should be prohibited from entering the swimming pool. Bath tubs, bath towels and other utensils should be disinfected. Medical units must make good disinfection and isolation to prevent cross-infection. Six, treatment 1, systemic medication metronidazole 400mg, 2-3 times a day, 7 days as a course of treatment; for the first time patients a single oral metronidazole 2g, can receive the same effect. Oral absorption is good, high efficacy, low toxicity, and easy to apply. Sexual partners should be treated at the same time. Gastrointestinal reactions, such as loss of appetite, nausea, vomiting, are occasionally seen after taking the drug. In addition, headache, rash and leukopenia are occasionally seen and should be discontinued once detected. Metronidazole can be excreted through breast milk, so if the drug is used during breastfeeding, it is better not to breastfeed during and within 24 hours after the drug is administered. 2. Local medication can be administered locally alone or in combination with systemic and local medication, with the combination being more effective. Metronidazole tablets 200mg should be inserted into the vagina once a night, 10 times as a course of treatment. Before topical administration, the vagina can be rinsed with 1% lactic acid solution or 0.1-0.5 acetic acid solution to improve the vaginal environment to improve the efficacy. Trichomonas vaginitis often recurs after menstruation, so if the test is negative for trichomonas after treatment, the leucorrhoea should be rechecked after each menstruation, and if the test is negative for 3 times, it will be called cured. 4.Cautions in treatment When the trichomonas test is negative after treatment, you should continue the treatment for one course after the next menstruation, in the same way as before, in order to consolidate the efficacy. In addition, in order to avoid repeated infections, underwear and washing towels should be boiled for 5-10 minutes to eliminate pathogens; married people should also check whether the male partner has genital trichomoniasis, prostate fluid has trichomonas, if positive, need to be treated at the same time.