Sexually transmitted infections via oral sex

Oral sex involves giving or receiving oral stimulation to the genitalia. It is a very common practice and may be performed on its own, or before or after sexual intercourse.

A number of studies have stated that oral sex is not necessarily safe. Both giving and receiving oral sex can lead to the transmission of sexually transmitted infections (STIs) or sexually transmitted diseases (STDs).

Herpes is the most common STD transmitted via oral sex. There are two main types of herpes simplex virus (HSV): HSV type 1, which usually causes cold sores around the mouth, and HSV type 2, which generally causes sores around the genitals. If a person has HSV type 1 and they give/receive oral sex to/from another person, herpes could be transmitted to the genital area of the other person, causing genital sores. This process can also work in reverse, with HSV-2 transmitting from the genitals to the mouth of the other person during oral sex, though this is rare.

Gonorrhoea can also be easily be transmitted via oral sex. The infection is usually passed from infected genitals to a person's throat, but can also be passed from an infected throat to a person's genitals.

Syphilis is easily transmitted during oral sex if a person's mouth comes into contact with an open sore or a skin rash caused by the infection.

It is possible, but thought to be not very common, for the human papillomavirus, which causes genital warts, to be transmitted through oral sex.

Chlamydia can infect the throat via oral sex, although this is an uncommon occurrence. People with chlamydia may not have any symptoms and may not be aware that they are infected with the disease.

The hepatitis A virus is found in human faeces, and may be passed on during anal-oral sex.

Hepatitis B, contained in sexual fluids and blood, may get transmitted during oral sex in a similar way to HIV. Hepatitis C is generally only contained in blood, and will only be transmitted if there is blood present during oral sex.

Gastrointestinal infections and parasites may be passed on during oral contact with the anus.

Transmission from an HIV positive receptive partner to an HIV negative active partner may occur when the active partner gets sexual fluid (semen or vaginal fluid) or blood (from menstruation or a wound somewhere in the genital or anal region) into a cut, sore, ulcer or area of inflammation somewhere in their mouth or throat.