This isn’t a guideline really, but an excellent booklet (I can’t link the actual booklet, but it’s easy to find on the above link). It is a one stop shop for all you need to know about STDs and sexual health. There’s far too much to summarise, but I would encourage you to spend 10 minutes scrolling through, so that you know what it covers. You can then refer back to it when you need.
BASHH | Sexually transmitted infections in primary care
10th May 2013 by Louise Hudman
"I have always valued real-person interactive support which the National Association of Sessional GPs has given in spades. It is particularly helpful for the older GP locums who may not be technologically savvy and may feel 'forced into' locum work at the end of their professional career when it wasn't necessarily a planned choice. "
Dr David Grant, GP, Lincolnshire