How is HIV transmitted ? HIV is found in substantial number in semen, blood & vaginal secretions. Hence if any of theses secretions enter body of a healthy person, then infection can be transmitted. Since semen & vaginal secretions are sexual fluids, unprotected penetrative sex with HIV infected person is an important route of transmission. This is predominant route of transmission of infection. Blood can be gain entry in another body during blood transfusion or due to sharing of used needles. The latter is common in intravenous drug abusers. It can also occur if needles & syringes are used without proper sterilization in hospitals. HIV can also be transmitted from mother to fetus. Can kissing lead to HIV transmission ?-- No concentration of HIV in saliva is very low. Large quantities of saliva are unlikely to be exchanged in kissing. Even if saliva contains HIV, it does not get transmitted unless there are some cuts/ bruises in mouth. Hence kissing is unlikely to lead to HIV transmission.