Diagnosis:
Bacterial Vaginosis
• Bacterial vaginosis (BV) is the most prevalent vaginal infection in women of reproductive age. It is associated with significant sequelae related to an increased incidence of pelvic inflammatory disease, mucopurulent cervicitis and endometritis, and increased risk of HIV acquisition. Acquisition is associated with sexual activity, either through transmission between partners or because sexual activity adversely impacts colonization with protective lactobacilli.
• The clinical diagnosis of BV is established when three of four Amsel’s criteria are met: clue cells on vaginal microscopy, positive results on KOH amine testing, vaginal pH greater than 4.5, and a watery, “fishy” vaginal discharge. Clue cells are squamous epithelial cells densely coated with small coccobacilli.
• BV is a noninflammatory infection defined as an imbalance in normal vaginal flora as evidenced by a shift from predominately gram-positive lactobacilli to gram-negative anaerobic bacteria (e.g., Prevotella species (spp.), Mobiluncus spp., Gardnerella, and Bacteroides spp. It is hypothesized that vaginal lactobacilli play a critical protective role in the vagina by producing bactericidal and virucidal agents, including lactic acid and bacteriocins, which prevent overgrowth of pathogens and other opportunistic organisms.
• The gold standard for laboratory diagnosis of BV is the Nugent Gram stain classification. The Nugent score measures the numbers of lactobacilli, Gardnerella (gram-negative coccobacillary), and Mobiluncus (curved gram-variable bacilli) morphotypes in each oil-immersion field. A score of 0 to 3 is normal, 4 to 6 is intermediate, and 7 to 10 is consistent with BV.
• Treatment for BV includes metronidazole or clindamycin.
