More than 30 different bacteria, viruses and parasites are known to be transmitted by sexual contact. The World Health Organization identifies eight of these as the main contributors to the incidence of sexually transmitted infections (STI).1 
Four of these conditions are currently curable, with three being bacterial – chlamydia (Chlamydia trachomatis), gonorrhoea (Neisseria gonorrhoeae), and syphilis (Treponema pallidum) – and trichomoniasis caused by the protozoa Trichomonas vaginalis. All can be treated with antibiotics. 
The other four – hepatitis B, herpes simplex virus (HSV), HIV and human papillomavirus (HPV) – are viral and as yet incurable, but they can be managed. 
Diagnosis and treatment of an STI will usually be undertaken by a specialist service. However, NICE does provide guidelines for treating STIs in primary care. Patients will usually be offered screening for other STIs and will be encouraged to inform current and recent partners of their infection.2