The way in which sexually transmitted infection (STI) services are delivered in the UK is hardly recognisable to those practising 20 or even 10 years ago, and the pace of change shows no sign of slowing. The changes have been driven by the need to modernise services and improve efficiency, and have had three main components: (1) improvements in information/communication technology; (2) new systems or pathways of care in clinics; (3) advances in diagnostic testing. Thus, we see the increased use of mobile phones and email to communicate with our patients, the integration of computer systems in laboratories with clinic computers, the use of the internet for health education and contact tracing, and also look forward to the holy grail of an electronic patient record.^1,2 We are also learning to use these information/communication technologies in a more productive way by changing the skill mix of clinic staff and reviewing patient care pathways to allow more patients to be seen alongside maintaining a high-quality service.³

In this changing environment, we must not forget that the accurate and timely diagnosis of STIs remains a core function of any genitourinary medicine or sexual health clinic. New technologies offer the tantalising prospects of more accurate diagnosis, faster turnaround times, and the collection of specimens by patients themselves, without the need for an examination. However, these developments should be viewed in the context of new commissioning and funding arrangements in the UK that will determine how quickly they can be implemented at a local level. Payment by results (PbR) currently pays a fixed tariff for each sexual health screen performed.⁴ But PbR is based on historical costs which do not incorporate these new laboratory technologies, and so, if we are to implement new tests to improve patient care, we have to agree to new standards. The specific issues are as follows:

• What constitutes an STI screen—which infections should be tested for and how should this be modified in the presence of different symptoms, sex or sexual orientation?

• What tests should be used for each infection—which tests are optimal or acceptable, and which are not recommended?

• What specimen should be used for each test?

The Sexually transmitted infection screening and testing guidelines⁵ provide an evidence-based approach to each of these issues. Commissioned by the Clinical Effectiveness Group of the British Association for Sexual Health and HIV, they have been developed under the appraisal of guidelines research and evaluation methodological framework,⁶ with contributions from over 20 national and international experts. The recommendations they contain were developed specifically for genitourinary medicine and sexual health clinics, but may also provide guidance in other healthcare settings which wish to optimise the diagnosis of STIs.

The guidelines are divided into two sections:

1. Summary tables: These recommend which tests should be taken and from what sites. Separate tables are available for heterosexual men, women, men who have sex with men, those presenting with genital discharge and those presenting with genital ulceration.

2. Testing guidelines for individual STIs: A separate chapter for each STI provides further detail on testing options and the evidence base for recommendations.

The guidelines have been designed to help clinicians decide which tests are most appropriate for their patients and are not intended to be prescriptive, although many of the recommendations are already standard practice. However, some others will need a modification in practice. These include:

• not screening for non-specific urethritis in asymptomatic men

• the use of nucleic acid amplification tests (NAAT) in preference to culture to detect herpes because of its improved sensitivity

• the inclusion of NAATs for gonorrhoea, although the guidelines continue to recommend the isolation of Neisseria gonorrhoeae to confirm gonococcal infection until the commercially available tests have been fully evaluated with different specimen types and in populations with both high and low prevalence.

For many years, standard teaching and practice in the UK, but not in all parts of the world, has been that a Gram-stained urethral smear was required as part of the routine examination of all male patients. This is still clearly indicated as part of the examination of symptomatic men in whom a diagnosis of gonorrhoea is a real possibility, and in these cases the smear may provide a rapid diagnosis. However, the evidence no longer supports routinely performing the urethral smear in men without symptoms. Those who advocate its continued use in this situation argure that a noticeable minority of men (17–36%^7–9) with chlamydial urethritis will receive an immediate diagnosis and hence treatment, following to the detection of urethritis by microscopy. In others diagnosis and treatment would be delayed, pending the result of a specific chlamydial test from a laboratory. However, contrary to this is the more powerful argument that the great majority, probably approaching 90%, of men with asymptomatic urethritis will not have any significant pathogen. This enormous overdiagnosis of a probable, or possible, sexually transmitted infection (depending on how the clinician seeks to explain the finding to the patient) can therefore lead to considerable unnecessary treatment and, as a result of notifying partners, considerable anxiety and damage to relationships, for both the male patients and their female partners.

The publication of the Sexually transmitted infection screening and testing guidelines provides an opportunity to take a consistent approach to STI screening and testing. They also give a basis for calculating future PbR tariffs and help create a level playing field for the provision of sexual health screening across the country.