Symptoms of vaginitis and vaginosis are seen frequently in clinical practice. The most common causes are bacterial vaginosis (BV), trichomoniasis, and vulvovaginal candidiasis. Because of significant clinical overlap in the symptoms, specific diagnostic testing may be required to guide appropriate antimicrobial therapy and patient management.
This test is based on pathogen detection by nucleic acid probe hybridization. The testing includes probes for the detection Gardnerella vaginalis (a marker for the disruption of the normal vaginal flora seen in BV), Candida species (for candidiasis), and Trichomonas vaginalis (for trichomoniasis).
The assessment of test accuracy depends on the populations studied, the comparator method, and other factors.
Sensitivity and specificity for detection of candidiasis in symptomatic women: 82% and 95%, respectively.
Sensitivity and specificity for detection of BV in symptomatic women: 98% and 100%, respectively.
Sensitivity and specificity for detection of trichomoniasis, compared to wet mount detection: 93% and 99%, respectively.
Turnaround time: 24 hours.
Specimen Collection and Transport Instructions
Vaginal fluid specimens should be collected only from patients with symptoms consistent with vaginosis or vaginitis.
Use only supplies provided in the Affirm VPIII transport system, sample collection set, or test kit for specimen collection.
Samples are collected from the posterior vaginal fornix, using an unlubricated (no water or jelly) speculum, ensuring that the entire circumference of the swab has been inoculated with vaginal secretions.
Place the swab into sample collection tube and snap on cap following the kit instructions.
Transport specimens according to kit instructions. Specimens may be transported at room temperature or refrigerated.
Interpretation
Expected results: Negative for all three pathogens. Negative results for a specific pathogen suggest that infection with that pathogen is unlikely.
Positive results: If one or more of the pathogens tested indicate infection when consistent signs and symptoms are present. Infection with more than one of the pathogens is not uncommon.
Limitations
Specimens must be collected, transported, tested, and interpreted using protocols described in the package insert of the kit used.
Performance of the test depends on optimal specimen collection.
Negative results do not exclude the possibility of infection with any of the specific pathogens.
Alternative testing, like pH, "amine test, " � and microscopic examination of vaginal fluid may be considered for the evaluation of patients.
The Affirm VPIII test does not detect infection by Neisseria gonorrhoeae or Chlamydia trachomatis; these pathogens and other possible causes of the patients symptoms should be considered, and ruled out as appropriate, in women presenting with vaginal discharge or other compatible symptoms.
The test cannot be used as a test of cure because DNA from nonviable pathogens may be detectable after resolution of infection.