What diagnostic tests should be ordered to check for Sexually Transmitted Infections (STI), bacterial vaginosis, and vaginal candidiasis (yeast infection)?

From the Guidelines

To check for sexually transmitted infections (STIs), bacterial vaginosis (BV), and vaginal yeast infections, a comprehensive approach including nucleic acid amplification tests (NAATs) for chlamydia and gonorrhea, blood tests for HIV and syphilis, and specific tests for trichomoniasis, BV, and yeast infections should be ordered.

Recommended Tests

• For STIs:
  • NAATs for chlamydia and gonorrhea using urine samples or vaginal/cervical swabs 1
  • Blood tests for HIV, syphilis (RPR or VDRL with confirmatory treponemal test), hepatitis B, and herpes simplex virus (if symptomatic) 1
• For trichomoniasis:
  • NAAT testing or microscopic examination of vaginal secretions can be performed 1
• For bacterial vaginosis:
  • Vaginal pH test (BV typically shows pH >4.5) 1
  • Microscopic examination of vaginal discharge for clue cells 1
  • Amsel's criteria assessment (which includes whiff test with potassium hydroxide) 1
• For vaginal yeast infections:
  • Microscopic examination with potassium hydroxide (KOH) preparation to visualize yeast cells and pseudohyphae 1
  • Vaginal culture for Candida species 1

Importance of Testing

These tests are essential for accurate diagnosis as symptoms of different vaginal infections can overlap. Early detection allows for prompt treatment, preventing complications such as pelvic inflammatory disease, infertility, or transmission to partners in the case of STIs. Testing should be conducted before starting any antimicrobial treatment to ensure accurate results 1.

Recent Guidelines

Recent guidelines from the Infectious Diseases Society of America and the American Society for Microbiology emphasize the importance of utilizing the microbiology laboratory for diagnosis of infectious diseases, including STIs, BV, and vaginal yeast infections 1.

Key Considerations

When ordering tests, it is crucial to consider the patient's symptoms, medical history, and risk factors for STIs. The choice of tests may vary depending on the patient's specific needs and the availability of testing methods in the healthcare setting 1.

From the Research

Diagnostic Tests for STI, Bacterial Vaginosis, and Vaginal Yeast Infection

To diagnose STI, bacterial vaginosis, and vaginal yeast infection, the following tests can be ordered:

• Nucleic acid amplification tests for gonorrhea, chlamydia, trichomoniasis, and Mycoplasma genitalium 2
• Serology for syphilis, typically using sequential testing to detect treponemal and nontreponemal antibodies 2
• Amsel criteria, Gram stain, or newer laboratory tests that detect Gardnerella vaginalis DNA or vaginal fluid sialidase activity for bacterial vaginosis 3
• Potassium hydroxide microscopy or DNA probe testing for vulvovaginal candidiasis 3
• Culture for complicated vulvovaginal candidiasis to identify nonalbicans strains of Candida 3

Additional Tests

Additional tests that may be useful in certain cases include:

• Wet mount or vaginal smear for the diagnosis of trichomoniasis or bacterial vaginosis 4
• Testing for other STIs, such as herpes simplex virus type 1 and 2, depending on the patient's symptoms and risk factors 2

Considerations for Testing

When ordering tests, it is essential to consider the patient's symptoms, medical history, and risk factors for STIs and other infections 2, 5, 4, 6. The choice of tests should be guided by the most likely causes of the patient's symptoms and the need to rule out other potential diagnoses.