HIV can be passed on through infected semen, vaginal fluids, rectal secretions, breast milk or blood. In Scotland, HIV is most commonly passed on through having vaginal or anal sex without a condom, or through sharing infected needles or other drug-injecting equipment.

However, myths persist about how people contract the virus.

HIV cannot be contracted through casual contact – touching, shaking hands, sleeping on bed linens, using towels or sharing cutlery (or even sharing toothbrushes or razors, though neither is recommended for hygienic reasons). Nor can HIV be transmitted through saliva – this includes spitting or kissing – or through faeces, urine, biting, scratching, insects, or by coming into contact with a discarded needle.

While there have been five cases in the UK of someone being infected with HIV by being pricked with a needle, all five of these cases were in healthcare settings, with no reported cases since 1999. HIV cannot live for more than a few minutes outside of the human body, so getting HIV is difficult unless you have unprotected sex or share drug-injecting equipment, such as needles.

Furthermore, if someone is already being treated for HIV, this makes that person even less likely to pass along the virus. There is now consensus that a person living with HIV, on treatment and with undetectable levels of the virus in their blood for at least six months has virtually zero risk of transmitting HIV to sexual partners. We have added our support to the Undetectable=Untransmittable campaign to reinforce this message.

Transmission of HIV can be prevented by always using a condom when having vaginal or anal sex. And while there is a relatively low risk of transmission during oral sex, use a condom or avoid giving oral sex if you have cuts, sores or ulcers in your mouth.  In addition to safe sex, never share needles or any other drug-injecting equipment.