How do you get it?

It can be passed on through blood and other body fluids (though not saliva).

It is spread through having unprotected sex with an infected partner or by injecting drugs if infected drug addicts share needles.

Before 1983 there were some cases of people catching Aids from blood transfusions, but this is virtually impossible now because blood is screened.

Pregnant women with Aids can pass the virus on to their babies at birth or through breast milk. This is the main way that children - especially in Africa - get Aids.