STIs are transmitted by vaginal, anal, and oral sex. Some STIs may spread to a baby during pregnancy, childbirth, or breastfeeding. Herpes can be transmitted by kissing, if herpes blisters are in the mouth or around the lips. Hepatitis B, syphilis, and HIV, the AIDS virus, can be spread by sharing needles or other objects contaminated by blood, as well as through sexual contact. STIs are not spread by handshakes, hugs, toilet seats, towels, dishes, telephone receivers, or insect bites.