Bacterial Vaginosis and Vulvovaginal Candidiasis Flashcards
Definition of bacterial vaginosis
Characterised by an overgrowth of predominantly anaerobic organisms (such as gardneralla vaginal, prevotella, mycoplasma hominis) and loss of lactobacilli. The vagina loses its normal acidity, and vaginal pH increases to greater than 4.5
Is BV a sexually transmitted infection
BV is not generally regarded as a sexually transmitted infection, however its prevalence is higher amongst sexually active women and is considered to be ‘sexually associated’.
What is the cause of BV
The exact trigger for BV is unknown, but symptoms are thought to appear when the vaginal pH rises, creating an abnormal environment which favours the growth of normal and abnormal bacteria
Risk factors for BV
Being sexually active, recent change in sexual partner, factors that raise vaginal pH (products such as douches, deodorant, bubble baths, shampoo, menstruation, presence of semen in the vagina), Cu-IUD, smoking
Protective factors against BV
- Hormonal contraception
- Consistent condom use
- Circumcised partner
Complications of BV
- Sexually transmitted infections: 2x increased risk of acquiring HIV, chlamydia, gonorrhoea
- Obstetric complications: Late miscarriage, Pre-term labour and delivery, PPROM, Spontaneous abortion, LBW, Postpartum endometritis, Post caesarean delivery wound infections, Post-surgical infections, Subclinical PID
How does loss of lactobacilli contribute to BV
Lactobacilli are the main component of the healthy vaginal bacterial flora. These bacteria produce lactic acid that keeps the vaginal pH low (under 4.5). The acidic environment prevents other bacteria from overgrowing. When there are reduced numbers of lactobacilli in the vagina, the pH rises. This more alkaline environment enables anaerobic bacteria to multiply
Presentation of BV
- Approximately 50% of women with bacterial vaginosis (BV) are asymptomatic
- Characterised by a fishy-smelling, thin, gre/white homogenous discharge that is not associated with itching or soreness
- Should ask about exacerbating factors including intercourse or during the menstrual cycle. Also need to ask about contributing factors: use of vaginal products, such as douches, deodorant, and vaginal washes, and the use of antiseptics, bubble baths, or shampoos in the bath.
Investigations for BV
- Palpate the abdomen (if appropriate) to assess for tenderness or a mass (which may indicate malignancy).
- Inspect the vulva for lesions, discharge, vulvitis, ulcers, and any other changes.
- Perform a speculum examination (except in a pregnant woman with a low-lying placenta) to visualize the cervix and vagina to look for characteristic signs of BV.
- BV is characterized by a thin, white/grey, homogeneous coating of the vaginal walls and vulva that has a fishy odour. The characteristic appearance of the discharge is not specific for BV but supports the diagnosis.
- BV is not usually associated with soreness, itching, or irritation.
- Test the pH of the vaginal discharge to help distinguish between BV and other causes:
- Collect from the left lateral wall of the vagina with a swab and narrow-range pH paper (3.8-5.5)
- Take a high vaginal swab (CHARCOAL SWAB) for gram staining an to exclude other causes of symptoms (bear in mind that there may be concomitant STI infection) if there is suspicion or if treatment fails.
- Test for chlamydia, gonorrhoea, trichomoniasis, HIV and syphilis if at high risk of an STI
CHaracteristic appearance of BV on microscopy
Clue cells.
Clue cells are epithelial cells from the cervix that have bacteria stuck inside them, usually Gardnerella vaginalis
Differentials for BV
- Candidiasis — characterized by a white, odourless, curdy discharge that may be associated with vulval itching and superficial soreness.
- Trichomoniasis — characterized by a fishy-smelling, yellow/green frothy discharge that may be associated with itching, soreness, and dysuria.
- Chlamydia — can cause vaginal discharge and dysuria and does not usually present with itch.
- Gonorrhoea — rarely presents with itch and is associated with pain and a purulent cervical discharge..
- Genital herpes — may present with redness, itch, and ulceration; discharge is uncommon; and acute vulval pain is often the defining symptom.
- Mixed infection — it is possible for two or more infections to coexist, such as BV together with candidiasis or trichomoniasis. Up to 10% of infections are mixed.
Management of BV
If the women is asymptomatic, treatment is not usually required, unless they are undergoing TOP
IF the woman is symptomatic:
* Advise that, where possible, they reduce exposure to contributing factors
* Prescribe oral metronidazole twice a day for 7 days
* If the woman prefers topical treatment or cannot tolerate oral metronidazole: Prescribe intravaginal metronidazole gel 0.75% once a day for 5 days, Oral clindamycin and oral tinidazole are alternatives
* In persistent BV in women with an IUD, consider removing the device and trying an alternative form of contraception
* In the unlikely event that a woman with confirmed BV has not responded to a 7-day course of oral metronidazole, consider discussing with a gynaecologist or genito-urinary medicine (GUM) specialist regarding further treatment
* Advise that recurrence is quite common (requires same treatment)
Definition of vulvovaginal candidiasis
Vulvovaginal candidiasis (genital thrush) is a symptomatic inflammation of the vagina and/or vulva caused by a superficial fungal infection (usually Candida yeasts).
Common causative organisms for vulvovaginal candidiasis
Candida albicans is the most common and accounts for 80-89% of cases
* C.glabrata is responsible for a further 5%
* C. tropicalis, C.parapsilosis, C.krusei and Saccharomyces account for the remaining cases
Candida yeasts are part of the normal flora of the mucous membranes of the female genital tract, but overgrowth can cause infection
Typical features of candidiasis
Typically causes symptoms of vulval or vaginal itch and irritation, and a non-offensive vaginal discharge
