Genito-Urinary Samples
General Information
STI check for Chlamydia and Gonorrhoea, (and Trichomoniasis in symptomatic females), is done by NAAT testing. (Aptima sample).
Annual STI check is recommended for all 18-25 year olds.
For the investigation of abnormal vaginal discharge, laboratory testing is often unnecessary. Primary investigation should include clinical observations, and testing the vaginal pH - (PHE July 2013). Downloadable flow chart for Investigation
LTHT Microbiology do NOT offer diagnostic testing for Bacterial Vaginosis (BV). This diagnosis is made on the basis of clinical observations and vaginal pH. Leeds Sexual Health offer consultancy and a referral service for patients with apparent recurrent or refractory BV. Leeds sexual health
pH is tested using narrow range pH paper. The paper should be placed directly on the lateral vaginal wall or discharge removed using a cotton bud/Q tip swab.
When requesting laboratory GUS culture tests on Order Comms, the result for vaginal pH will determine the relevant investigations to be undertaken.
Routine” culture of High Vaginal Swabs (HVS) in asymptomatic patients is of no value.
Culture for N gonorrhoeae is only available if there is strong suspicion of gonorrhoea, and treatment is planned. Swabs should be processed within 6 hours. Referral to LSH is recommended in such cases.
For detection of group B streptococci (GBS) in pregnancy, a high vaginal swab may be sent. Note that a positive MSSU with GBS during pregnancy warrants peripartum antibiotic prophylaxis irrespective of GBS status on HVS culture – therefore, sending HVS for screening for GBS is unwarranted in this case.
Intrauterine devices should NOT be routinely sent to the laboratory after their removal. IUCDs are only investigated if there are clinical indications of PID or other inflammatory conditions.
High Vaginal Swab for culture (NB, investigation does NOT include STI screening)
Specimen types you should send:
- High vaginal swab (HVS). Indications for HVS are: -
Symptoms consistent with recurrent thrush, vaginal pH < 4.5
Abnormal discharge NOT consistent with BV or TV, vaginal pH > 4.5
Abnormal discharge in a patient who is > 60 years old or who has dyspareunia or dysuria Group B streptococcal screening in pregnancy
How to collect the sample
- Remove all excessive amount of secretions or discharge.
- Obtain samples from the mucosal membrane of the vaginal vault. Use a speculum if available.
Which container does it go in?
- HVS for culture: Liquid e-Swab (NB these are not investigated for STIs)
- A guide on the use of liquid swabs.
Transport
- Swabs should be transported to the laboratory as soon as possible.
- Cultures for Neisseria gonorrhea are valid up to 24 hours from collection to receipt of sample
Other GUS tests
IUCD - If Actinomyces is suspected or shown in the endocervical smear, separate prolonged culture techniques are required and the clinical information must be clearly stated on the request form.
Pregnancy - Group B Strep may cause neonatal invasive disease. Send an HVS for screening. Women known to be carriers of group B strep at onset of labour are offered parenteral prophylaxis.
Children- Vulval and penile swabs from children are investigated for skin/soft tissue pathogens including Staph aureus and Group A haemolytic streptococcus.
Suspected sexual abuse – refer urgently to Consultant Paediatrician. Documented procedure for clinical examination and testing, and chain of custody documentation, is mandatory.
Culture for N gonorrhoeae - only when GC treatment is planned
Referral to LSH is recommended for investigation/treatment of gonorrhoea
(This will permit rapid laboratory processing and will facilitate contact tracing and expert support)
Chlamydia, Gonorrhoea and Trichomonas vaginalis NAAT testing
An annual STI check is recommended for all 18-25 year olds for infection with Chlamydia trachomatis or Neisseria gonorrhoea (GC)
Screen for Trichomonas vaginalis in patients with dysuria, strong suspicion of infection or with pH greater than 4.5 and a distinctive yellow/green frothy discharge. Vaginal swabs
Testing may also be indicated for eye swabs, use the white aptima collection device for this sample and specifically request Chlamydia/GC.
All samples must be sent in Aptima collection kits. Do not use Copan liquid swabs or UTM red capped tubes for this investigation.
Do not send multiple genital swab requests for MMCS and NAAT testing in the same sample bag as this leads to delays in testing.
Male or Female Urine Specimen Collection Guidance
Endocervical or Male Urethral Specimen Collection Guidance
An annual STI check is recommended for all 18-25 year olds for infection with Chlamydia trachomatis or Neisseria gonorrhoea (GC)
Screen for Trichomonas vaginalis in patients with dysuria, strong suspicion of infection or with pH greater than 4.5 and a distinctive yellow/green frothy discharge. Vaginal swabs
Testing may also be indicated for eye swabs, use the white aptima collection device for this sample and specifically request Chlamydia/GC.
All samples must be sent in Aptima collection kits. Do not use Copan liquid swabs or UTM red capped tubes for this investigation.
Do not send multiple genital swab requests for MMCS and NAAT testing in the same sample bag as this leads to delays in testing.