What are the signs and symptoms of bacterial vaginosis, chlamydia, and gonorrhea?

Signs and Symptoms: Bacterial Vaginosis vs Chlamydia vs Gonorrhea

Bacterial vaginosis presents with homogeneous white discharge and fishy odor, while chlamydia and gonorrhea typically cause mucopurulent cervicitis—but critically, up to 50% of BV cases and the majority of chlamydial/gonococcal infections are asymptomatic.

Bacterial Vaginosis

Key Clinical Features 1

Symptomatic presentation (present in only 50% of cases):

• Homogeneous, white, noninflammatory discharge that smoothly coats vaginal walls
• Fishy odor (especially after intercourse or with menses)
• Vaginal malodor

Diagnostic signs:

• Vaginal pH >4.5
• Positive "whiff test" (fishy amine odor with 10% KOH)
• Clue cells on microscopy (>20% of epithelial cells)
• Notably absent: vulvar inflammation, vaginal erythema, or irritation

Important Clinical Pitfall

BV is noninflammatory—if you see vulvar inflammation or significant irritation, consider other diagnoses 1.

Chlamydia (Cervicitis)

Key Clinical Features 2, 3

Most commonly asymptomatic, but when symptomatic:

• Mucopurulent endocervical discharge (visible in endocervical canal)
• Abnormal vaginal discharge
• Intermenstrual vaginal bleeding (especially post-coital)
• Sustained endocervical bleeding with gentle swabbing

Associated findings:

• Leukorrhea (>10 WBC per high-power field)
• May progress to pelvic inflammatory disease with adnexal tenderness, cervical motion tenderness

Critical Distinction

Chlamydia causes cervicitis (inflammation at the cervix), not vaginitis. The discharge originates from the endocervix, not the vaginal walls 2, 3.

Gonorrhea (Cervicitis)

Key Clinical Features 2, 4

Clinical presentation overlaps significantly with chlamydia:

• Mucopurulent cervical discharge
• Endocervical inflammation and friability
• Abnormal vaginal discharge
• Intermenstrual bleeding

Distinguishing features:

• Often more purulent discharge than chlamydia
• Can cause urethritis with dysuria
• Pharyngeal infection typically asymptomatic
• Rectal infection often asymptomatic

On examination:

• Gram stain may show gram-negative intracellular diplococci (GNID) in only 50% of infected women 2

Comparative Diagnostic Algorithm

Step 1: Assess Discharge Character

• Thin, homogeneous, coating walls → Consider BV
• Mucopurulent from cervical os → Consider chlamydia/gonorrhea
• Thick, white, clumpy → Consider candidiasis (not asked but important differential)

Step 2: Check pH

• pH >4.5 → BV or trichomoniasis (not chlamydia/gonorrhea)
• pH ≤4.5 → Candidiasis or normal

Step 3: Perform Whiff Test

• Positive (fishy odor) → BV
• Negative → Does not rule out chlamydia/gonorrhea

Step 4: Microscopy

• Clue cells → BV
• Increased WBCs without organisms → Cervicitis (chlamydia/gonorrhea)

Step 5: Assess Inflammation

• No inflammation → BV
• Cervical inflammation/friability → Chlamydia/gonorrhea

Critical Clinical Pearls

Asymptomatic presentation is the rule, not the exception:

• 50% of BV cases are asymptomatic 1
• Majority of chlamydia infections are asymptomatic 3
• Gonorrhea frequently asymptomatic, especially at extragenital sites 4

Location matters:

• BV affects the vagina (noninflammatory)
• Chlamydia/gonorrhea affect the cervix (inflammatory) 2, 3

Multiple infections can coexist:

• C. trachomatis or N. gonorrhoeae can sometimes cause vaginal discharge 1
• Sexually transmitted organisms detected in 16% of women with BV or candidiasis 5
• Always test for multiple pathogens in at-risk populations 6, 5

Testing is essential:

• Clinical diagnosis alone is unreliable—symptoms and signs overlap significantly 7
• NAATs are preferred for chlamydia and gonorrhea diagnosis 6
• Clinical criteria for BV require 3 of 4 findings (discharge character, clue cells, pH >4.5, positive whiff test) 1