Chlamydia can also infect the throat, though it is less common. Like gonorrhea, it may not always produce clear symptoms, making it possible for someone to carry and spread the infection without realizing it. Syphilis, another bacterial infection, can spread through oral contact if a person comes into contact with a syphilis sore, which may appear on the genitals or mouth.
Herpes simplex virus (HSV) can also be transmitted during oral sex. If a partner has genital herpes, the virus may spread to the mouth or lips. Likewise, if someone has oral herpes (commonly known as cold sores), it can be transmitted to a partner’s genital area during oral contact.
Although the risk of contracting HIV through swallowing semen is relatively low compared to other forms of unprotected sex, it is still possible, particularly if there are open sores, bleeding gums, or cuts in the mouth. These openings can allow viruses to enter the bloodstream more easily.