Oral sex (where your partner uses his or her mouth on your clitoris and genital area) is considered safe regarding transmission of HIV.
Vaginal fluids are relatively low in HIV concentration, and the mouth has very good protective immune mechanisms, including saliva. Sexually transmissible infections such as herpes and gonorrhoea, however, can be transmitted through oral sex.
There have been no documented cases of transmission of HIV from vaginal fluid in the mouth, but there may be some risk in exceptional circumstances, such as when you have your period and your partner has an open mouth wound, or an open ulcer or lesion in or around the mouth. As a general rule, don’t let someone go down on you with a cold sore or ulcer unless they use a barrier, as they may transmit something to you – such as herpes – and the risk of you transmitting HIV to him or her also increases.
Latex sheets known as dental dams or condoms slit length ways have sometimes been advocated for ‘safe’ oral sex, but these are considered unnecessary in terms of HIV prevention (the exception here is in the occupational context for sex workers, who often seek to minimise any microbial contact by using barriers as much as possible).
There is no risk of HIV acquisition for your partner/s if you perform oral sex on them.
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