Patient confidentiality or friend loyalty?

You are a nurse, and one day a young male patient named Kane comes in for a sexual health check up. While Kane does not recognise you, you recognise him as the guy who your best friend, Amelia, went on a couple of dates with a a few weeks ago, and you are aware that they had engaged in sexual intercourse. Upon receiving Kane's tests results, you discover that he has tested positive for syphilis. While your first thought is to immediately inform Amelia of the news, as there is a high chance that she too may have contracted the disease, you are also aware that this would be a direct breach of patient confidentiality. However, you are deeply concerned about Amelia and feel as though she should know so that she can go and get herself tested.