Michael Addidle Bacterial Vaginosis

What is Bacterial Vaginosis (BV) ? Polymicrobial vaginal infection involving a reduction in the amount of Lactobacilli bacteria and an overgrowth of anaerobic bacteria.

Some key facts Condition first described by Gardner and Dukes in Initially thought to be due to which organism? Most common infective cause of vaginal discharge in women of childbearing age. Prevalence is approximately 20-30% Approximately 50% symptomatic The absence of inflammation is the basis of the term vaginosis as opposed to vaginitis

Risk Factors for BV Multiple or new sexual partners Oro-genital sex Smoking Genetic predisposition

Normal vaginal flora ? What else is normal vaginal flora? What part does age play in the make-up of normal vaginal flora?

Pathogenesis Normal vaginal flora in women of reproductive age is predominately lactobacilli. (Bit unusual) At puberty eostrogen levels increase, stimulates glycogen uptake by vaginal epithelial cells. Glycogen one of main food sources of lactobacilli. Lactobacilli produce both lactic acid and hydrogen peroxide. Vaginal epithelial cells also produce lactic acid as a by- product of glycogenolysis. This makes the vaginal pH acidic The hydrogen peroxide is also toxic against other bacterial species. Lactobacilli per se are very low virulence bacteria. (Pro- biotic yoghurts etc), therefore its predominance is thought to have a protective effect against vaginal/pelvic infections. At menopause, eostrogen levels decrease so lactobacilli often become non-dominant. Makes BV more difficult to diagnose

Names to remember in BV Amsel Nugent Hay

Presentation of BV Amsel’s Criteria (introduced 1984) ( 3 out of 4 criteria below required to establish the diagnosis ) Vaginal discharge, thin white/grey Fish like odour. (accentuated by addition of Potassium Hydroxide KOH) Vaginal PH >4.5 (Litmus paper is a bedside test) Presence of clue cells on laboratory examination. What are the problems with Amsel’s criteria?

Introduced 1991

Hay’s Criteria (2002) Problems with Hay’s criteria?

Other methods DNA probes DNA probes + pH

Bacterial Vaginosis: Quality Assurance of results Condition of degrees Clear cut at either end of the spectrum. Those in the middle (including AVF) are less clear cut. Degree of subjectivity External QC/Internal QC?

The consequences of Bacterial Vaginosis Causal relationship between BV and endometrial bacterial colonisation, endometritis, premature labour, post- partum fever, post-hysterectomy vaginal cuff cellulitis and post-abortal infection. BV is a risk factor for HIV transmission (&other STDs). May be due to the lack of hydrogen peroxide producing lactobacilli in the vaginal flora of women with BV

Bacterial vaginosis : Treatment Metronidazole 400mg orally bd for 7 days. Clindamycin 300mg orally bd for 7 days. Metronidazole and Clindamycin gels can also be used. Avoid gels during pregnancy. No evidence that they reduce the risks to the baby. No evidence to suggest that woman’s response to therapy and risk of relapse are influenced by treatment of her male sex partner.

Screening and treatment of asymptomatic infection Generally asymptomatic infection not treated as patients often spontaneously improve and therapy often complicated by symptomatic vaginal yeast infection. Treatment indicated for asymptomatic women who are about to undergo gynae procedures(in particular termination of pregnancy) and in “high risk pregnancies.” No evidence that treating sexual partners of women with BV is beneficial.

Bacterial Vaginosis (BV) in pregnancy (15-30%) Why is BV a particular problem in pregnancy –More common than in non-pregnant pop. –Associated with premature labour & delivery –Controversial association with miscarriage –Post-partum endometriosis However treatment of BV may not return these risks to baseline levels. Benefit greatest in those higher risk pregnancies.

When to look for and treat BV in pregnancy Asymptomatic High Risk Pregnant women (previous pre-term delivery). Can consider screening these women for BV even if asymptomatic. There is no evidence for routine screening for BV in pregnancy in all expectant mothers.

Bacterial Vaginosis:Relapse 30% recurrence in 3 months 50% recurrence in 12 months Long term suppressive antibiotics may be indicated when three or more episodes within a 12 month period.