What triggers bacterial vaginosis?

Triggers of Bacterial Vaginosis

Bacterial vaginosis (BV) is primarily triggered by a disruption of normal vaginal flora, specifically associated with having multiple sexual partners, douching, and lack of vaginal lactobacilli. 1, 2, 3

Pathophysiology

• BV results from replacement of normal H₂O₂-producing Lactobacillus species in the vagina with high concentrations of anaerobic bacteria (e.g., Prevotella sp. and Mobiluncus sp.), Gardnerella vaginalis, and Mycoplasma hominis 1, 3
• This microbial alteration leads to a shift in vaginal ecology that creates an environment favorable for pathogenic bacteria 4
• The protective role of H₂O₂-producing Lactobacillus species is diminished, allowing overgrowth of anaerobic bacteria 4

Risk Factors and Triggers

• Sexual activity related factors:

  • Having multiple sexual partners is strongly associated with BV development 1, 2
  • Women who have never been sexually active are rarely affected 1
  • Despite the association with sexual activity, BV is not clearly defined as a sexually transmitted infection 1, 3

• Hygiene practices:

  • Douching disrupts normal vaginal flora and is associated with increased BV risk 1, 2
  • Use of certain vaginal products that alter vaginal pH can contribute to BV development 5

• Microbiome disruption:

  • Depletion of protective Lactobacillus species, particularly those producing H₂O₂ 2, 3
  • Antibiotic use can sometimes trigger BV by eliminating beneficial bacteria 6

Important Clinical Considerations

• BV is the most prevalent cause of vaginal discharge or malodor, affecting approximately 29.2% of women worldwide 5
• Up to 50% of women with BV may be asymptomatic despite having the clinical condition 1, 3
• BV has a high recurrence rate, with 50-80% of women experiencing recurrence within a year after antibiotic treatment 6, 3
• Treatment of male sexual partners has not been beneficial in preventing BV recurrence 1, 3

Clinical Implications

• BV is associated with serious reproductive health complications:
  • Increased risk of preterm birth and adverse pregnancy outcomes 1, 7
  • Higher susceptibility to sexually transmitted infections 3, 6
  • Increased risk of pelvic inflammatory disease 3, 7
  • Postoperative infections following gynecological procedures 8

Prevention Strategies

• Limiting number of sexual partners may reduce risk 2, 3
• Avoiding douching and other practices that disrupt vaginal flora 1, 2
• Using condoms may provide some protection 6
• Maintaining vaginal pH in the normal acidic range (below 4.5) 2, 5
• Smoking cessation may help reduce risk 6

Understanding these triggers is essential for both prevention and management of BV, particularly given its high recurrence rate and potential complications for reproductive health.