Bacterial vaginosis Flashcards
Define bacterial vaginosis
overgrowth of predominantly anaerobic organisms and a loss of lactobacilli. The vagina loses its normal acidity, and its pH increases to greater than 4.5.
What are the causes of bacterial vaginosis
Gardnerella vaginalis
Prevotella species
Mobiluncus species
Atopobium vaginae
Megasphaera type 1
What are the risk factors for bacterial vaginosis
Being sexually active
The use of douches, deodorant, and vaginal washes; menstruation; and presence of semen in the vagina.
Copper intrauterine device
Smoking
What are the protective factors for bacterial vaginosis
Hormonal contraception use
Consistent condom use
Circumcised partner
What are the symptoms of bacterial vaginosis
50% asymptomatic
Vaginal discharge (thin, white)
Fishy odour
Otherwise painless
What are the differentials for bacterial vaginosis
Candidiasis
Trichononiasis
Chlamydia
Gonorrhoea
Genital herpes
Mixed infection
Malignancy
Atrophic vaginitis
What are the signs of bacterial vaginosis on examination
Abdominal exam: assess for masses
Pelvic examination
- Thin, white/grey, homogeneous coating of the vaginal walls and vulva that has a fishy odour
When can you treat for BV without investigation
Low risk of STI
Not pregnant
No other symptoms of other conditions
Symptoms have no developed pre or post gynae procedure
Not postnatal or post miscarriage
Not pre or post TOP
This is a first episode of suspected BV, or if recurrent, a previous episode of recognizably similar symptoms was previously diagnosed to be BV following examination.
What investigations should be done for BV
Usually clinical diagnosis
Bedside:
- Vaginal pH testing: >4.5 (alkaline)
- High vaginal swab for wet mount microscopy: clue cells
- Vaginal swab gram stain: lactobacillus reduced/absent
- “whiff” test: positive
Bloods: HIV serology, syphilis serology
Describe the whiff test
addition of 10% potassium hydroxide to the vaginal sample → presence of volatile amines
What is Amsel’s criteria for diagnosis of BV
3/4 should be present:
thin, white homogenous discharge
clue cells on microscopy: stippled vaginal epithelial cells
vaginal pH > 4.5
positive whiff test (addition of potassium hydroxide results in fishy odour)
What is the management for bacterial vaginosis
Asymptomatic: hygiene advice, treatment not required
Symptomatic: oral metronidazole 2x a day for 7 days and GUM referral
Second line: intravaginal/oral clindamycin
What hygiene advice should be given for bacterial vaginosis
Bubble Bathing
Sexual activity
Copper IUD
Vaginal pH increase
Avoid vaginal douching, shower gel, use of shampoo in bath
What are the complications of bacterial vaginosis
pregnancy complications: Late miscarriage, Preterm birth, PROM, Postpartum endometritis
Increased risk of acquiring and transmitting STIs
What is the prognosis for bacterial vaginosis
Metronidazole has a 70-80% initial cure rate
relapse rate > 50% within 3 months
