Complications
1. Most GU depts use a diagnosis based on the microscopic appearance of a Gram-stained smear of vaginal discharge, the Ison / Hay criteria:
Grade 1: lactobacilli predominate (this is normal)
Grade 2: some lactobacilli but other organisms present (intermediate) Grade 3: few / absent lactobacilli – lots of other organisms (this is BV)
2. Another diagnostic method uses Amsel’s criteria: 3 out of 4 make the diagnosis...
1. Thin white homogenous discharge
2. pH of vaginal fluid > 4.5 (normal is 3.5 to 4.5 )
3. Release of fishy odour on adding alkali (10% KOH) to drop of discharge on a microscope slide 4. ‘Clue cells’ (vaginal epithelial cells covered in bacteria) seen on microscopy
Both of these diagnostic criteria rely on microscopy and, in the case of Amsel’s criteria, the use of 10% KOH which is very caustic and potentially dangerous outside of a laboratory setting.
Clearly, these are difficult to do in a GP setting, and the diagnosis of BV in primary care may, for the time being, have to be a pragmatic one based simply on the presence of a malodorous discharge with a raised pH and no soreness / irritation (see figure 2)
Some pathology labs diagnose BV on a microscope slide
■ prepared in the lab from a high vaginal swab, or
■ taken directly in GP and sent to the lab in a protective box ( similar to the old Cx smear boxes)
Talk to your lab / GU service about the locally preferred method for diagnosing BV outside of GU settings
NB:
■ The isolation of Gardnerella vaginalis on HVS culture should not be used to diagnose BV because it is found in 30 to 40% ‘normal’ women.
■ New point-of-care tests exist and perform adequately, but are not yet widely available
■ NAAT tests detecting BV-associated bacteria are under development
5. Bacterial vaginosis (BV)
5. Bacterial vaginosis (BV)
Figure 2: Vaginal discharge in Primary Care algorithm (adapted from ref 2)
■ Manage as appropriate
■ TV suspected? d/w GUM / refer
■ Uncertain diagnosis? Refer Rx for BV
Eg:
METRONIDAZOLE 400 mg po b.d 5 to 7 days
or 2 g po stat
Rx for Candida Eg:
FLUCONAZOLE 150 mg po stat
or CLOTRIMAZOLE
500 mg PV stat
History
See above
■ Not sexually active or
■ Low risk of STIs or
■ None of the conditions listed on the right
Examination declined Examination accepted
■ High risk of STIs – < age 25 – previous STIs – recent new partner or
> 1 partner in past year
■ Upper reproductive tract Sx
■ Bloody discharge
■ Uncertain Sx
■ Pregnant, post partum, post ToP, post instrumentation
■ Recurrent Sx or failed Rx
Examine and investigate
■ Vaginal pH
■ Endocervical swabs for Chlamydia and Gonorrhoea plus bloods for HIV and syphilis
■ Consider a high vaginal swab
■ ? urine dipstick
■ ? pregnancy test
■ Bimanual examination if PID suspected
■ Foreign body?
■ Other Consider examination
and investigations based on clinical findings Syndromic Rx based on Hx
Pt to return if Sx do not improve or if they recur
pH ≤ 4.5
Malodour, no itch Itch, no malodour pH > 4.5
Treatment
General advice:
■ Avoid vaginal douching / bubble baths / antiseptics etc, which can affect the normal vaginal flora allowing BV to develop
■ Exclude STIs if Hx suggests possible risk
■ No need to routinely Rx male partner (but there are no data on Rx’ing female partner in lesbian couples)
Treatment is indicated for:
■ Symptomatic women
■ Women undergoing some surgical procedures
■ Some pregnant women (those with Sx)
Recommended regimens:
■ METRONIDAZOLE 400 mg to 500 mg po bd for 5 to 7 days (ok in pregnancy) (cost = approx £0.70)4 or
■ METRONIDAZOLE 2 g po stat (BNF recommends avoiding this high dose in pregnancy) (£0.30)4 or
■ METRONIDAZOLE 0.75% vaginal gel pv od 5/7 (£4.31)4 or
■ CLINDAMYCIN 2% intravaginal cream pv od 7/7 (£10.86)4 or
■ TINIDAZOLE 2 g po stat (approx £2.76)4 or
■ CLINDAMYCIN 300mg po bd 7/7 (approx £13.70)4
NB:
■ Oral Metronidazole and Tinidazole may interact with alcohol (no data on effects of alcohol with Metronidazole vaginal gel, but probably best avoided)
■ The 2 g stat dose of Metronidazole may be inferior to other doses. None are superior
■ Allergic to Metronidazole? use Clindamycin cream
■ Clindamycin (oral and topical) may be linked with pseudomembranous colitis
■ Vaginal gel / creams may weaken condoms
■ A test of cure is not needed if Sx resolve
■ Non-antibiotic-based Rx’s with probiotic lactobacilli or lactic acid preparations: poor evidence – no recommendations on their use to treat acute episodes can be currently made.
BV in pregnancy
■ Not enough evidence to recommend routine screening of all pregnant as yet
■ Pregnant with Sx of BV? Rx as above
■ Pregnant with incidental finding of BV but no Sx? insufficient evidence that Rx will prevent pre-term birth
■ Pregnant with additional risk factors for pre-term birth? may benefit from Rx before 20/40
■ Metronidazole is safe to use in 1st trimester (but avoid high doses such as 2 g stat)
5. Bacterial vaginosis (BV)
Breastfeeding
■ Systemic Metronidazole and Clindamycin enter breast milk. May be prudent, therefore, to use intravaginal Rx
Termination of Pregnancy
■ Risk of endometritis and PID, so BV should be screened for and Rx’d if found.
Sexual partners
■ No need to routinely screen and Rx male partner
■ Unsure if female partner in WSW (lesbian) couples need concurrent Rx. ? May help.
Follow-up
■ ToC not needed if Sx resolve
Recurrent BV
■ No specifically agreed definition
■ Up to 70% can get it again within 3/12 of Rx ?Why
■ Doesn’t appear to be antibiotic resistance
■ Seems to simply be re-emergence of the BV associated bacteria
■ Normal vaginal flora (lactobacilli) don’t seem to fully re-establish
■ Difficult to manage. Optimum Rx has not been established. Discuss this with the Pt realistic expectations
■ Possible options (consider combinations of these options) – Lifestyle measure ( stop smoking, avoid douching) – Review contraceptive methods (see above)
– Getting partner Rx’d ‘just in case’ does not seem to make a difference – no need for routine Rx.
One study5 conducted in an STD clinic population reported a very high rate of non-gonococcal urethritis (NGU) in male partners (> 70%) so there might be some rationale for checking for NGU, but no RCT conducted.
Suggest d/w GUM.
Management options should take into account the interplay between vaginal pH and the growth of normal or abnormal bacteria.
5. Bacterial vaginosis (BV)
Figure 1
/ VAGINAL pH / MIXED ANAEROBES
/ LACTOBACILLI
■ Antibiotics.
Consider episodic, anticipatory, pulse or suppressive Rx for 4 to 6 months.3 Eg:
■ METRONIDAZOLE 400 mg po bd for 3/7 at start and end of menstruation or
■ METRONIDAZOLE 2 g po stat once a month or
■ METRONIDAZOLE 0.75% vaginal gel pv twice a week for 16 weeks
NB
■ Even with Metronidazole maintenance Rx, symptoms may recur after stopping Rx
■ Candida may occur during Rx
■ Acidifying agents
■ Mixed evidence, small studies
■ Two lactic acid vaginal gel products are currently available for prescription and OTC sale in the UK. See BNF
■ Consider using for alternate evenings for 1 month or longer if required2
■ Probiotic / Lactobacilli preparations
■ Conflicting evidence
■ No firm recommendation can be made at present
References
1. UK national guideline for the management of bacterial vaginosis 2012 BASHH Clinical Effectiveness Group
Available at www.bashh.org.uk/guidelines
2. The management of vaginal discharge in non genito-urinary medicine settings 2012 Faculty of Sexual and Reproductive Healthcare, Clinical Effectiveness Unit ISSN 1755-103X Available at www.fsrh.org and www.bashh.org/guidelines
3. Oxford Handbook of Genitourinary Medicine, HIV and Sexual Health (2nd Ed) Pattman et al
Oxford University Press 2010 ISBN 978-0-19-957166-6 4. British National Formulary March 2013
BMJ Group and RPS publishing www.bnf.org
5. An association between non-gonococcal urethritis and bacterial vaginosis and the implications for patients and their sexual partners
Keane, et al
Genitourin Med 1997;73:373-377 doi:10.1136/sti.73.5.373
5. Bacterial vaginosis (BV)
Background
1Cause
■ ~ 92% cases: Candida albicans
■ ~ 8% non-albicans sp
■ eg: C glabrata, Saccharomyces cerevesiae, C.Krusei
■ May respond poorly to standard antifungal courses.
■ can arise spontaneously or 2º to disturbance of vaginal flora (e.g. recent antibiotics)
Symptoms
(not all may be present)■ Vulval / vaginal itch / soreness, external dysuria, external dyspareunia (beware other causes of these Sx, such as dermatoses, herpes, Trichomonas)
■ Vaginal discharge
Signs
(not all may be present)■ Erythema, fissures (diferential diagnosis = herpes), satellite lesions, excoriation
■ Discharge (typically curdy, but may be thin); generally no malodour (cf: BV)
■ Vulval oedema
Note:
■ Symptoms and signs are no guide to species
■ 10 to 20% women without symptoms harbour Candida species (no treatment needed if no symptoms)
■ It is mostly uncomplicated, unless
■ Severe symptoms (subjective)
■ Pregnant
■ Recurrent (> 4 symptomatic episodes / year)
■ Non-albicans species (particularly persistent infections)
■ Abnormal host factors (immunosuppression, diabetes, oestrogen levels)