The mouth is therefore generally regarded as an unlikely route of HIV transmission. The tissue of the mouth and oesophagus is also very thick compared with genital tissues, and fluids stay in contact with it for a very short time because swallowing clears the mouth regularly. Only one cell type found in the mouth is vulnerable to HIV infection (Campo). HIV is not able to infect most cells in the mouth. How could HIV infect the mouth and throat? There are no reported cases of HIV transmission through kissing. There are no reliable reports of HIV being transmitted from the mouth to the genitals.Ĭases of transmission via cunnilingus are extremely rare, and the reliability of these reports is questionable. However, infection via insertive fellatio (‘having it done to you’) is probably exceedingly low risk. Infection via receptive fellatio (‘doing it’) is biologically plausible and may happen occasionally. Very few cases of transmission through oral sex have been reported amongst gay men despite the continued practice of oral sex (often with ejaculation into the mouth) by large numbers of men over many years. The latest news and research on sexual transmission If undamaged, the tissues of the mouth and throat are thought to be less susceptible to infection than genital or anal tissues, and an enzyme in saliva also acts to inhibit HIV. When HIV is not fully supressed, the risk of HIV transmission through the mouth is certainly smaller than through vaginal or anal intercourse. The PARTNER 1 and PARTNER 2 studies showed that HIV is not transmitted through condomless vaginal or anal intercourse when a person with HIV is taking antiretroviral treatment and has a fully suppressed viral load (Rodger).Īs the risk of transmission through oral sex is estimated to be much lower than for vaginal and anal intercourse in the absence of antiretroviral therapy, it is implausible that the risk of transmission through oral sex is not affected in the same way as other sexual transmission risks when effective treatment suppresses viral load. Most case reports concern receptive fellatio (‘doing it’) rather than insertive fellatio or cunnilingus.The risk of getting HIV through oral sex is low, but not non-existent, when a person with HIV does not have fully suppressed viral load.HIV cannot be sexually transmitted by an HIV-positive partner with a fully suppressed viral load.