Vaginitis is the most common gynecological disease. Trichomoniasis, mycotic vaginitis and bacterial vaginosis are transmitted through sexual contact and are sexually transmitted diseases. Atrophic vaginitis and vaginitis in infants and children are often caused by low estrogen levels and reduced local resistance and are not infectious. The transmission of trichomoniasis is through: (1) Sexual contact: About 70% of men become infected after having unprotected sex with a female patient. The chances of transmission from men to women through sexual intercourse may be higher. Since men are often asymptomatic after infection with trichomonas, they can easily become the source of infection. (2) Indirect transmission can occur through public baths, bath tubs, bath towels, swimming pools, bidets, clothing or contaminated equipment. 2. Transmission of mycosis fungoides: (1) Mainly endogenous transmission. Pseudomycetes are parasitic in the vagina, but also in the mouth and intestines. It is a conditionally pathogenic bacteria and can cause infection once the conditions are suitable. (2) A small number of patients can be directly infected through sexual intercourse. (3) Very few patients may be infected indirectly through contact with infected clothing. (3) Bacterial vaginosis: This is a mixed infection caused by a dysbiosis of the normal flora in the vagina. It is often aggravated after sexual intercourse, so it can be transmitted through sexual intercourse.