How is HIV transmitted ?

Three main routes are recognised for the transmission of HIV:

• Unprotected sexual contact with an infected partner – the majority of infections occur during sexual contact, when the virus can enter the body via the lining of the vagina, vulva, penis, rectum or mouth.

• Contact with infected blood – HIV can be transmitted through contact with infected blood, for example, during blood transfusions. Sharing of needles between intravenous drug users can also result in transmission as needles may be contaminated with minute quantities of blood containing the virus.

• From mother to child during pregnancy, birth or breastfeeding – this is known as vertical transmission. The risk can be reduced by antiretroviral therapy for pregnant women who are infected with HIV, and by delivering babies by caesarian section.