When performing an Aptima vaginal swab, which test(s) should be ordered?

Aptima Vaginal Swab Testing

When performing an Aptima vaginal swab, you should order the Aptima BV (Bacterial Vaginosis) assay and/or the Aptima CV/TV (Candida/Trichomonas Vaginitis) assay, depending on the clinical presentation—these are nucleic acid amplification tests (NAATs) that detect the three most common causes of infectious vaginitis. 1

Understanding the Aptima Platform

The Aptima system uses transcription-mediated amplification (TMA) technology to diagnose vaginitis. There are two separate assays available:

1. Aptima BV Assay

• Detects bacterial vaginosis by measuring the loads of:
  • Gardnerella vaginalis
  • Atopobium vaginae
  • Lactobacillus species (in relation to overall bacterial load)
• Demonstrates 95.0% sensitivity and 89.6% specificity compared to Nugent scoring 2
• Shows 98.8% sensitivity and 77.7% specificity against Hay/Ison criteria 3

2. Aptima CV/TV Assay

• Combined test detecting:
  • Candida species (C. albicans and resistant species like C. glabrata/krusei)
  • Trichomonas vaginalis
• For Candida: 91.7% sensitivity and 94.9% specificity 2
• For T. vaginalis: 96.5% sensitivity and 95.1% specificity 2

Clinical Decision Algorithm

Order based on symptoms:

• Abnormal vaginal discharge with pH >4.5 and/or fishy odor → Order Aptima BV
• Abnormal vaginal discharge with pH <4.5 and/or vulvar symptoms → Order Aptima CV/TV
• Undifferentiated vaginal symptoms or mixed presentation → Order both assays

The Aptima assays significantly outperform traditional methods (wet mount sensitivity 40-80%, culture for Trichomonas ~70%) 1, 4.

Specimen Collection

The vaginal swab should be:

• Collected from vaginal discharge or vaginal epithelium
• Placed in laboratory-provided transport medium specific to the Aptima system
• Stored at room temperature for up to 7 days (or per manufacturer's recommendations) 1

Important note: The same specimen collection device is often used for Chlamydia trachomatis/Neisseria gonorrhoeae NAAT testing, allowing simultaneous STI screening 1.

Key Advantages Over Traditional Methods

The Aptima assays demonstrate higher sensitivity and specificity than clinicians' diagnoses and in-clinic assessments (wet mount, pH testing, whiff test) 2. This is particularly important because:

• Wet mount microscopy requires live organisms and has poor sensitivity (40-70%) 1
• Traditional culture methods miss many infections
• Point-of-care tests have widely variable performance 1

Common Pitfalls to Avoid

1. Don't rely solely on clinical criteria (Amsel criteria, pH testing)—molecular testing is superior 1
2. Be aware of increased detection rates: Aptima assays may identify asymptomatic colonization, potentially leading to higher treatment rates 5
3. For intermediate Nugent scores: Aptima BV testing is particularly useful for clarifying diagnosis 6
4. In recurrent cases: Consider adding antifungal susceptibility testing if Candida is detected 1, 7

The Aptima platform represents the current standard for molecular diagnosis of vaginitis, with FDA clearance for symptomatic females and validated performance across multiple clinical studies 1, 3, 2.