The source of venereal disease transmission is the infected patient and the blood or secretion containing the pathogen. The channels of transmitting can be classified as sexually transmitted infection or non-sexually transmitted infection.

1. Sexually transmitted infection

Sexual behaviors such as sexual intercourse, oral sex, anal sex, French kiss, etc. can all transmit venereal disease, but sexual intercourse is the main channel. Over 95 percent of the patients were infected this way.

2. Non-sexually transmitted infection

A healthy person with the wound on the skin or cut on the mucosa who directly touches the degenerative festered wound or the secretion of the patient can be infected.

（1）Indirect contact. One can be infected with venereal disease by touching the underwear, clothes, bedding, toilet, etc. contaminated by the patient.

（2）Infection through blood. Transmissible infection occurs if one transfuses blood from the patient who is infected with AIDS or syphilis. For example, by using the same injecting needle.

（3）Placenta infection. When a pregnant woman is infected with venereal disease, the pathogen will be transmitted to the infant through the placenta, for instance，congenital syphilis.

（4）Birth canal infection. The pathogen can be transmitted to the infant through the birth canal during the parturition. For example, a lying-in woman during her gonococcal infection can infect the infant with gonococcal ophthalmia and gonococcal Pustulosis.

（5）Iatrogenic infection. During the medical treatment, the medical staff is infected due to the poor protection, such as when examining or operating on the patient, changing medicine for him/her, or due to the cut on the skin by the medical apparatus containing the pathogen, and the carelessly sterilized medical apparatus can also cause him/her the infection.（6） Other channels. Artificial Insemination, organ transplant and tattoo can all cause the infection.