Non-Sexually Transmitted Diseases Flashcards
Define BV
Bacterial vaginosis is a non-sexually transmitted infection of the lower genital tract
Occurs due to distrubance in normally vaginal flora and subsequent increase in pH
Pathophysiology of BV
Normal vaginal flora is disturbed, leading to a reduction in the numbers of lactobacilli bacteria in the vagina.
Lactobacilli are large rod-shaped organisms that produce hydrogen peroxide to help maintain the acidic pH of the vagina <4.5 hence inhibiting the growth of other microorganisms.
When lactobacilli populations are reduced, the pH rises, allowing growth of other microorganisms.
Infection is often polymicrobial, but the most common organisms found are Gardnerella vaginalis, anaerobes and mycoplasmas.
Risk factors for BV
Sexual activity – particularly a new partner or multiple sexual partners
The use of a contraceptive intrauterine device (IUD)
Receptive oral sex
Presence of an STI
Vaginal douching, or the use of scented soaps/vaginal deodorant
Recent antibiotic use
Ethnicity – more common in black women
Smoking
Clinical features of BV
Whilst up to 50% of case are asymptomatic, symptoms can include:
- Offensive fishy smelling vaginal discharge
- Not usually associated with soreness, itching or irritation
- Thin, white/grey, homogenous vaginal discharge on examination
Differential diagnosis of BV
Vaginal Candidiasis – profuse thick white, itchy curd-like discharge
Trichomonas vaginalis – thin, frothy, offensive discharge, with associated irritation, dysuria and vaginal inflammation
STIs (gonorrhoea/chlamydia)
Investigations for BV
Diagnosis of BV relies on history, vaginal examination and microscopic examination.
Microscopy is the preferred method for diagnosis whereby a high vaginal smear (HVS) is gram stained and evaluated for:
- The presence of ‘clue cells’ – vaginal epithelial cells studded with Gram variable coccobacilli
- Reduced numbers of lactobacilli
- Absence of pus cells
- The isolation of G. vaginalis is not sufficient to diagnose BV, as it can be cultured from the vagina of more than 50% of uninfected women.
Amsel’s criteria for BV
Thin and white homogenous discharge
Clue cells
PH>4.5
Positive whiff test
Managment of BV
Metronidazole - PO or topical
Avoid vaginal douching, scented shower gels, antiseptic agents and shampoos in bath
Consider removal of IUD
Risks of untreated BV in pregnancy
Premature birth
Miscarriage
Chorioamnionitis
Treatment is metronidazole but lower dose
Pathophysiology of vulvovaginal candidiasis
Commonly caused by candida albicans
- yeast like fungus
- found as part of the body’s normal flora i GI tract
Risk factors of vulvovaginal candidiasis
Pregnancy
Diabetes
Use of broad spectrum antibiotics - alter the normal vaginal micro-biota, allowing candida the opportunity to flourish and grow
Use of corticosteroids
Immunosuppression or compromised immune system
Clinical features of vulvovaginal candidiasis
Pruritus vulvae
Vaginal discharge - white, curd-like non-offensive candida
Dysuria
Erythema and swelling of vulva
Satellite lesion - red, pustular lesions with superficial white/creamy pseudomembranous plaques
Curd-like discharge
Differential diagnosis of vulvovaginal candidiasis
BV Trichomonas vaginalis UTI Contact dermatitis Eczema and psoriasis
Management of vulvovaginal candidiasis
Initial course of intravaginal antifungal - clotrimazole Oral antifungal - fluconazole Topical imidazole Reassess after 7-14 days
Candidiasis of pregnancy
Increased risk due into increased oestrogen
- stimulates increased glycogen production
- promotes growth
