Syphilis is a bacterial infection that is usually passed on through having sex with someone who is infected. It can also be passed from an infected mother to her unborn child and, in rare cases, can be caught through injecting drugs.
It is extremely rare to catch syphilis through a blood transfusion in the UK as blood donors are carefully screened.
For full details of Syphilis click here to be taken to the NHS Choices website. If you are worried you may be at risk of having an STI or have any symptoms (as mentioned on the NHS Choices link to Syphilis), you should visit your local sexual health or GUM clinic to have them checked out.
(Link checked as correct on 18/10//2013 by SH next update due 18/4/2014)