Bacterial vaginosis: Difference between revisions

m (Rossdonaldson1 moved page Bacterial Vaginosis to Bacterial vaginosis)
 
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==Background==
==Background==
*Accounts for up to 50% of cases of vaginitis
*Is a vaginal dysbiosis resulting from replacement of the normally dominant ''Lactobacillus'' species in the vagina, with high concentrations of [[anaerobic bacteria]].
*Associated w/ preterm labor and premature rupture of membranes
*Is '''not''' an infection, nor is it sexually transmitted, although it is associated with sexual activity.
*Treat all symptomatic women (including pregnant)
*Accounts for up to 50% of cases of [[vaginitis]]
*Do not treat asymptomatic women (including pregnant)
*Associated with [[preterm labor]] and premature rupture of membranes


==Diagnosis==
==Clinical Features==
*whitish-gray discharge and odor
*Whitish-gray [[vaginal discharge]] and odor
**Lack of discharge makes diagnosis less likely
**Lack of discharge makes diagnosis less likely
*Wet mount shows clue cells: bacteria that line the borders of the vaginal epithelial cells
*May have history of "physiologic whiff test" after contact with male ejaculate which is alkaline (like KOH)
*Whiff Test: fishy odor with 10% KOH added


==Differential Diagnosis==
==Differential Diagnosis==
{{Vulvovaginitis DDX}}
{{Vulvovaginitis DDX}}


=Treatment=
==Evaluation==
*Do NOT need to treat sexual partner
===Work-up===
*2 Options: [[Metronidazole]] or [[Clindamycin]]
[[File:Clue Cell.jpg|right|thumbnail|A '''"clue cell"''': note effacement of borders by bacteria, as compared to normal epithelial cells below.]][[File:Wet Mount Normal Cell.jpg|right|thumbnail|Normal vaginal epithelial cells on wet mount: note clean borders. Presence of lactobacilli (tiny rods) is normal.]]
*Wet mount shows '''clue cells''': vaginal epithelial cells with "stippled appearance" due to coverage by bacteria
*Whiff Test: fishy odor with 10% KOH prep
*CDC recommends testing all women with BV for HIV and other STDs <ref name="cdc" />
 
===Diagnosis===
''Amsel criteria (3/4 must be present)''
*Homogeneous, thin, gray-white discharge
*Positive whiff test
*Vaginal pH>4.5
*Clue cells on wet mount (at least 20% of epithelial cells)
 
==Management==
*No need to treat if asymptomatic
**In pregnant patients, consider treating to prevent preterm birth, though evidence is conflicting<ref>Cochrane Database of Systemic REviews. January 2013. Antibiotics for treating bacterial vaginosis in pregnancy. https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0010584/</ref>
*Consider partner treatment to reduce risk of recurrence<ref>Vodstrcil LA, et al. Male-Partner Treatment to Prevent Recurrence of Bacterial Vaginosis. N Engl J Med. 2025 Mar 6;392(10):947-957. doi: 10.1056/NEJMoa2405404. PMID: 40043236.</ref>
*Does ''not'' need a test of cure
 
===[[Antibiotics]]===
===[[Antibiotics]]===
{{BV Antibiotics}}
{{BV Antibiotics}}


==Disposition==
*Discharge


==See Also==
==See Also==
*[[Vulvovaginitis]]
*[[Vulvovaginitis]]


==Source==
==References==
<references/>
<references/>
[[Category:OB/GYN]]
 
[[Category:OBGYN]]
[[Category:ID]]
[[Category:ID]]

Latest revision as of 14:47, 6 May 2025

Background

  • Is a vaginal dysbiosis resulting from replacement of the normally dominant Lactobacillus species in the vagina, with high concentrations of anaerobic bacteria.
  • Is not an infection, nor is it sexually transmitted, although it is associated with sexual activity.
  • Accounts for up to 50% of cases of vaginitis
  • Associated with preterm labor and premature rupture of membranes

Clinical Features

  • Whitish-gray vaginal discharge and odor
    • Lack of discharge makes diagnosis less likely
  • May have history of "physiologic whiff test" after contact with male ejaculate which is alkaline (like KOH)

Differential Diagnosis

Vulvovaginitis

Evaluation

Work-up

A "clue cell": note effacement of borders by bacteria, as compared to normal epithelial cells below.
Normal vaginal epithelial cells on wet mount: note clean borders. Presence of lactobacilli (tiny rods) is normal.
  • Wet mount shows clue cells: vaginal epithelial cells with "stippled appearance" due to coverage by bacteria
  • Whiff Test: fishy odor with 10% KOH prep
  • CDC recommends testing all women with BV for HIV and other STDs [1]

Diagnosis

Amsel criteria (3/4 must be present)

  • Homogeneous, thin, gray-white discharge
  • Positive whiff test
  • Vaginal pH>4.5
  • Clue cells on wet mount (at least 20% of epithelial cells)

Management

  • No need to treat if asymptomatic
    • In pregnant patients, consider treating to prevent preterm birth, though evidence is conflicting[2]
  • Consider partner treatment to reduce risk of recurrence[3]
  • Does not need a test of cure

Antibiotics

First Line Therapy[4]

  • Metronidazole 500 mg PO Twice Daily for 7 days OR
  • Metronidazole gel 0.75%, one full applicator (5 g) intravaginally, Daily for 5 days OR
  • Clindamycin cream 2%, one full applicator (5 g) intravaginally Nightly for 7 days

Metronidazole does not cause a disulfiram-like reaction with alcohol.[5]

Alternative Regimin

  • Clindamycin 300 mg PO BID for 7 days OR
  • Clindamycin ovules 100 mg intravaginally qHS for 3 days (do not use if patient has used latex condom in last 72 hours)

Other regimens have been studied and have varying efficacy compared to placebo but due to cost and availability do not represent alternatives outside of absolute contraindications to preferred regimens.


Pregnant

  • Metronidazole 500mg PO Twice a day x 7 days[4]
  • Metronidazole 250mg PO Three times a day has also been studied[6][7]
  • Although metronidazole crosses the placenta, no evidence of teratogenicity or mutagenic effects among infants has been reported in multiple cross-sectional, case-control, and cohort studies of pregnant women[4]

Prophylaxis (Sexual Assault)

Disposition

  • Discharge

See Also

References

  1. Cite error: Invalid <ref> tag; no text was provided for refs named cdc
  2. Cochrane Database of Systemic REviews. January 2013. Antibiotics for treating bacterial vaginosis in pregnancy. https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0010584/
  3. Vodstrcil LA, et al. Male-Partner Treatment to Prevent Recurrence of Bacterial Vaginosis. N Engl J Med. 2025 Mar 6;392(10):947-957. doi: 10.1056/NEJMoa2405404. PMID: 40043236.
  4. 4.0 4.1 4.2 CDC Sexually Transmitted Infections Treatment Guidelines, 2021.[1]
  5. Is combining metronidazole and alcohol really hazardous?[2]
  6. Reduced incidence of preterm delivery with metronidazole and erythromycin in women with bacterial vaginosis[3]
  7. Effect of metronidazole in patients with preterm birth in preceding pregnancy and bacterial vaginosis: a placebo-controlled, double-blind study[4]
  8. Sexual Assault and Abuse and STIs – Adolescents and Adults[5]