High Vaginal Swabs and the Management of Vaginal Discharge
There is now good evidence that:
- Around 10,000 HVSs are done in Lothian each year. The overwhelming majority are negative, and most of the remainder show clinically irrelevant growth (eg. E Coli) and do not help treatment choices.
- The commonest important sexually-transmitted infection (STI) is chlamydia, and this can be diagnosed using a low vaginal swab and not a HVS. The swab can be self obtained. (SOLV)
- Trichomonas Vaginalis (TV: less than 50 cases a year) and gonorrhoea (GC: 20 cases in women each year) are very rare (Lothian figures).
- History and clinical assessment render the use of HVS redundant for the vast majority of women presenting to primary care with a vaginal discharge.
- Of the HVS results that are clinically relevant, almost all show Bacterial Vaginosis (BV) or Candida (thrush), both of which can easily be diagnosed on the basis of symptoms +/- speculum examination.
- Lothian Audits have confirmed that the majority of HVSs are unnecessary.
Reducing the number of HVSs done in Lothian Primary Care would benefit patients, minimising unnecessary testing and worry, and allow immediate treatment without follow-up appointments. Practice Nurses often undertake swabs, and the updated rationale for management should reduce their workload.
Information from several sources has been used for the guidance, including primary care and laboratory data in Lothian, Scottish STI statistics, and evidence-based guidance from the Faculty of Family Planning and Reproductive Health Care Clinical Effectiveness Unit and the British Association for Sexual Health and HIV.
In summary, the guidance is simple:
- Most discharge is physiological.
- If a woman has no concerns about, or history suggestive of, a STI, empirical treatment on the basis of symptoms and signs is appropriate: swabs are not required.
- Testing vaginal pH is useful for diagnosing BV.
- If there is a risk of STI (age<20, change of partner in last year, sex with a partner from abroad) and no alarm features, then the first investigation is a SOLV swab for Chlamydia. Clinicians in Lothian are under-testing for chlamydia in high risk women. Sex abroad, particularly in Asia, Eastern Europe or Africa is arguably the only feature suggesting high risk of other STIs & indicating referral to CHalmers, particularly if they test positive for gonorrhoea.
- If symptoms persist, refer women to Chalmers (in West Lothian refer to GUM & FP clinics at Howden)
The above does not apply if symptoms:
- suggest upper reproductive tract infection (PID),
- occur during pregnancy, post-partum or after miscarriage, abortion or other gynaecological surgery/procedure (including IUD insertion). In these situations further assessment and testing is indicated, with referral in some circumstances.
Guidance developed by Lothian LMC, the Primary Care Laboratory Interface Group, Microbiology Laboratories, and Chalmers Sexual and Reproductive Heatlh Service.
If you would like practice-based teaching, or support, on any of these areas, please contact Alison Craig, Nurse Consultant, Sexual and Reproductive Health at Chalmers Sexual Health Centre, 2a Chalmers Street, Edinburgh (0131 536 1540 - direct dial). Both medical and nurse Consultants are available - the latter specifically for educational sessions for PNs.