These activities are: Unprotected sexual intercourse, sharing needles, breastfeeding and/or direct blood to blood contact with an HIV positive person.
Anal sex without a condom
- Receptive/bottom – Anal sex without a condom is the highest risk activity for contracting HIV. This is because of the biology of the anus which is designed to absorb nutrients into the bloodstream from food passing through. This means it can absorb the HIV virus from infected semen. There is also a very high concentration of cells in the anus that are especially vulnerable to HIV infection, unlike other parts of the body.
- Insertive/top – HIV is more easily transmitted from the insertive to the receptive partner, but neither position is safe. During sex, the lining of the rectum of the receptive partner (‘bottom’) can get damaged and HIV can enter the bloodstream of the insertive partner either through the eye of the penis or through small cuts on the skin.
Vaginal sex without a condom
- Receptive – While not as extreme of a risk as anal sex, vaginal sex without a condom still poses a high risk of passing on HIV from infected semen or pre-cum.The virus can be transmitted through the lining of the vagina and absorbed into the bloodstream.
- Insertive – While being the insertive partner in vaginal sex carries less risk than being receptive, HIV in infected vaginal fluids can still enter a man’s body through the tip of his penis, the inner folds of his foreskin, or through small cuts on the skin.
Oral sex presents a very low risk of HIV transmission. There is an enzyme in saliva that acts as a natural defence to HIV. Having an open and bleeding wound in your mouth does increase the risk of oral HIV transmission slightly, but there would need to be a significant amount of semen containing a high HIV viral load coming into direct contact with the wound. If the wound were very minor, it’s unlikely that this would happen.
This describes HIV transmission from mother to child. It is one of the more common risk factors in developing countries, but due to technology and medical screening.
Blood to blood transmission most commonly occurs when a needle is shared between injecting drug users, where one user is HIV positive. In New Zealand, due to the work of Needle Exchanges across the country, this is no longer a regular occurrence and the risk factor for intravenous drug users has been largely reduced.
Not at Risk of contracting HIV
You are not at risk of contracting HIV if you;
- hug or kiss someone, or
- share cups, drink bottles or utensils with someone.
- Body fluids like saliva, sweat or urine do not contain enough of the virus to infect another person.