How is HIV transmitted?

HIV can only be passed on through infected blood, semen, vaginal fluids or breast milk.

HIV is mainly transmitted through vaginal or anal intercourse without a condom or by sharing a needle or syringe with someone who's living with HIV.

Other ways that HIV is transmitted are:

• By giving oral sex (although this is rare and will usually only occur if a person has cuts or sores in their mouth).
• From a mother to her baby during pregnancy, birth or breastfeeding (though less than one per cent of babies born to HIV positive mothers in the UK acquire HIV).
• From a needle stick injury in a healthcare setting (although there has not been a case in the UK for more than five years).
• From a blood transfusion or blood products (in the UK all blood and organs are carefully screened to prevent this but in some countries this may not happen).

It's impossible to transmit HIV through saliva and HIV cannot be passed on through casual contact such as kissing or sharing glasses or cutlery. HIV is a very fragile virus so doesn't live long outside the body.