Herpes infection can cause sores or breaks in the skin or lining of the mouth, vagina, and rectum. This provides a way for HIV to enter the body. Even without visible sores, having genital herpes increases the number of CD4 cells (the cells that HIV targets for entry into the body) found in the lining of the genitals. When a person has both HIV and genital herpes, the chances are higher that HIV will be spread to an HIV-uninfected sex partner during sexual contact with their partner’s mouth, vagina, or rectum.
'Using condoms or dams can help to protect against STIs, but herpes can also be passed on by skin-to-skin contact with the affected area, so it’s strongly recommended that you don’t have sex during this time,' she adds. 'This includes direct genital contact or skin-to-skin contact with the affected area, and doesn’t have to be penetrative sex,' says O’Sullivan.