BASHH, the British Association for Sexual Health and HIV, I find are the resource for managing GUM conditions. Listed in this link are all their current guidelines. A vital resource. Just do remember to check on local resistance rates, particular with ref to Gonorrhoea.
Travelling the world….
TRAVAX is a good site outlining what vaccinations people need and where. You do need to register to access it, but is free if done so.
Fit For travel is a handy alternative.
Part of our role is to inform public health of the notifiable diseases. Here is a link to the HPA site with the form on the right.