Hi, there!
First of all, only Hepatitis B, C and HIV are viruses, not syphilis.
We can do PCR tests (viral load) for Hepatitis B and C, as well as for HIV1 only, not for HIV2, but is extremely rare (and it would be detected by the antibody anyway). The costs are as follows (as you can see very expensive tests and not always appropriate and necessary): Hepatitis B viral load £200, Hepatitis C viral load £170 and HIV viral load £220, but you also would need to add the consultation fee of £125. Shypilis PCR is £95.
Best wishes,
Jose