Trichomonas vaginitis (trichomona1vaginitis) is a common form of vaginitis, caused by Trichomonas vaginalis. Trichomonas is pear-shaped with a pointed posterior end, about two to three times the size of a multinucleated leukocyte. The body has four flagella at the tip, a fluctuating membrane at the body, and an axial column projecting from the posterior end. Live trichomonads are transparent and colorless, droplet-shaped, the flagella swing with the fluctuation of the fluctuating membrane, the life history of trichomonads is simple, only the trophozoite and no encysted period, the trophozoite is more vigorous, can survive 2 days at 3-5 ℃; survive 20-60 minutes at 46 ℃; survive about 10 hours in a semi-dry environment; can also survive 45-120 minutes in ordinary soapy water. It does not grow in environments below Ph5 or above 7.5. The vaginal pH of patients with trichomonas vaginalis is usually 5.1 to 5.4. Trichomonas, which is hidden in glands and vaginal folds, is often able to multiply before and after menstruation and causes inflammatory episodes. It consumes or engulfs glycogen in the vaginal epithelial cells and hinders lactic acid production. Trichomonas is not only parasitic in the vagina. It also often invades the urethra or paraurethral glands, and even the bladder and renal pelvis, as well as the male prepuce, urethra or prostate.
I. Causes
Direct transmission: through sexual intercourse; indirect transmission: through public baths, tubs, baths, swimming pools, toilets, clothing, instruments and dressings.
Trichomonas vaginalis is acquired from outside infection. For an infectious disease to spread, there must be three conditions: the source of infection, the means of transmission, and the susceptible person.
Anyone can be infected with trichomonas, and those with altered vaginal pH or immune deficiencies are more likely to be infected. Very few patients are able to recover from trichomoniasis infection and even if they are cured, they can be re-infected next time. The source of transmission of trichomoniasis is the carrier and the contaminated objects.
There are two ways of transmission: direct transmission, i.e. sexual transmission, and indirect transmission. In foreign countries, trichomoniasis is mainly transmitted through sexual intercourse and is therefore classified as a sexually transmitted disease. In our country, the mode of transmission is different. Because of our large population and relatively poor public health facilities compared to developed countries, transmission in public places has become an important route of transmission. For example, if the chairs in public baths or the toilets in public toilets are contaminated with the secretions of insect carriers, then the later may be infected if they sit directly on the chairs or toilets. In addition, the spread of trichomonas can be caused by the tubs in public baths, swimming pools with high density and poor disinfection in summer, borrowing and wearing others’ underwear, and renting swimsuits.
In addition, the use of bath tubs between family members and medical cross-infection are also causes of indirect transmission of trichomonas.
Gynecologists suggest that the pathogen of this disease is Trichomonas vaginalis. Trichomonas is a parasite that is invisible to the naked eye. It is pear-shaped, 10 – 30 μm long, with four flagella of equal length to the worm’s body on its head, and can be clearly seen under a microscope. Trichinella is very adaptable to different environments and can grow and reproduce at 25℃–42℃, survive at a low temperature of 3℃–5℃ for 21 days, and still survive for 20–60 minutes at 46℃, and can survive for several hours in semi-dry conditions after being separated from the human body. Trichomonas parasitizes not only the vagina, which is deprived of oxygen, but also invades the urethra and paraurethral glands, and even travels up to the ureter and renal pelvis. The most suitable pH for the growth of Trichomonas is 5.5 to 6. If the pH is below 5 or above 7.5, the growth of Trichomonas is inhibited.
Pathogenesis
Trichomonas vaginalis belongs to the genus Trichomonas in the order Trichomonadinae in the phylum Protozoa – Animal flagellates. The trophozoites are pear-shaped or ellipsoidal, 7-32?m long and 5-12?m wide, colorless and transparent, refractive, with four anterior flagella and one posterior flagellum. The posterior flagellum extends backward along the fluctuating membrane, but does not free from the fluctuating membrane. The fluctuating membrane is from the base of the hairs to one side, which occupies about half of the worm body. The nucleus is mostly located in the anterior 1/3 of the worm body and is oval and foamy.
The pathogenesis of Trichomonas is poorly understood due to the lack of ideal animal models. Trichomonas vaginalis infects humans as a trophozoite and becomes spherical when exposed to unfavorable growth conditions.
Trichomonas adheres to vaginal epithelial cells through its surface lectins (AP65, AP51, AP33, AP23) and cysteine proteases and directly contacts and destroys target cells through mechanical damage by amoeboid movement and cytotoxic effects of secreted proteolytic enzymes and proteolytic enzymes, and induces the production of inflammatory mediators, finally leading to epithelial cell lysis and abscission and local inflammation. Trichomonas has hemophilic and alkaline-resistant properties, consumes and engulfs glycogen in vaginal epithelial cells, uses glycogen and iron from host cells for energy metabolism, engulfs Lactobacillus, and hinders lactic acid production. It can induce immune responses in the body, including cellular immunity, humoral immunity, activation of complement response, stimulation of host cells to produce some cytokines, leading to local inflammatory changes.
The ability to destroy isolated target cell nuclei varies between strains of Trichomonas, and the intrinsic toxicity varies between strains.
Clinically, it has been found that trichomoniasis is often aggravated after menstruation and that the use of oral contraceptives has resulted in a shift to negative trichomonas vaginalis, which is associated with hormonal effects on the vaginal epithelium and changes in the complement of the receptor, leading to a greater vulnerability of the epithelium to trichomonas.
Common symptoms
Yellowish green leucorrhea with foam, vulvar itching, painful intercourse
IV. Clinical manifestations
The main symptoms of trichomonas vaginalis are increased leucorrhea with thin foam and itching of the vulva. If the urethra is infected, 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. There is a lot of leucorrhea in the posterior fornix, which is grayish yellow, yellowish white thin liquid or yellowish green purulent discharge, often foamy. The vaginal mucosa may have no abnormal findings in those with worms. A small number of patients have trichomonas in the vagina without an inflammatory reaction and are called carriers. It is believed that Trichomonas alone cannot cause inflammation because it consumes glycogen in vaginal epithelial cells, changes vaginal pH, disrupts defense mechanisms, and promotes secondary bacterial infections, so it often causes inflammatory episodes when the vaginal Ph changes around menstruation, during pregnancy, or after childbirth.
V. Complications
Trichomonas vaginalis often coexists with other vaginitis, and the United States reports that about 60% are combined with bacterial vaginosis. Trichomonas vaginalis can engulf sperm and prevent lactic acid production, which affects sperm survival in the vagina and can therefore complicate infertility.
Because Trichomonas parasites not only live in the vagina, but also invade the urethra and the male foreskin fold and prostate fluid, the male partner should be treated at the same time for married patients. If only the wife is treated but not the husband, even if the wife is cured, she will be re-infected by the husband through sexual intercourse. If the wife is not treated, the wife will be re-infected by the husband through sexual intercourse.