Vaginal Swabs Are Appropriate Specimens for Diagnosis of Genital Tract Infection with Chlamydia trachomatis

Abstract

NAATs were performed on FCU, urethral, cervical, self-and clinician-collected VS. Sensitivity was compared to isolation using cervical and urethral swabs. Agreement of NAAT results between VS and cervical swabs or FCU was calculated. Specimens from 2,517 15-to 25-year-old asymptomatic women attending clinics at nine different centers were evaluated. Results with self-and clinician-collected VS were equivalent and were at least as good as results with FCU and cervical swabs. Across all sites, summary specificities for all specimens were >99%. Among culture-positive women, NAAT sensitivity with VS (93%) was as high as or higher than NAAT sensitivity with cervical swabs (91%) or FCU (80.6%) or culture of cervical swabs (83.5%). VS are appropriate specimens for diagnosing chlamydial genital tract infection by NAATs. That patients can efficiently collect them offers important benefits for screening programs. It would be beneficial for public health programs if the NAAT manufacturers sought FDA clearance for this specimen.

The prevalence of urogenital micro-organisms detected by a multiplex PCR–reverse line blot assay in women attending three sexual health clinics in Sydney, Australia

“…Recent studies have shown that PCR testing for Chlamydia using self-collected vaginal swabs is just as sensitive as using endocervical specimens (Garrow et al, 2002;Schachter et al, 2003). Detection rates of target organisms using self-collected vaginal swabs in this study were similar to those for endocervical specimens.…”

Genital Chlamydia trachomatis infections

“…non è mai stata una metodica di routine perché decisamente complessa, costosa e non standardizzabile. La coltura cellulare è stata per lungo tempo considerata il "gold standard" poiché ha una specificità del 100%, ma la sua sensibilità varia dal 50 al 90% secondo i diversi studi (1,8,47,101). La sensibilità è legata anche al numero di microrganismi presenti nel campione e al loro stato replicativo: la presenza di una forma persistente di C.t.…”

“…Più recentemente sono stati introdotti nella pratica diagnostica, test basati sull'amplificazione di acidi nucleici (NAATs). L'amplificazione del genoma permette di produrre un numero molto elevato di sequenze geniche identiche e di migliorare la sensibilità del test (101). Questi metodi amplificano sia un gene cromosomico, il gene omp 1 codificante per il MOMP, sia l'RNAr presente in circa 1000 copie per microrganismo, sia una sequenza del plasmide criptico specifico di C.t.…”

“…L'impiego di NAATs consente di diagnosticare un'infezione da C.t. con un elevato grado di sensibilità e specificità utilizzando anche campioni "alternativi" rispetto ai classici tamponi uretrali e cervicali come il primo getto di urine, i tamponi vaginali o vulvari (67,101). La diagnosi di infezione da C.t., basata sull'utilizzo del tampone vaginale, si attesta su livelli di efficacia pari o superiori ai più tradizionali mezzi di indagine mediante coltura ed ai più moderni metodi di indagine mediante tecniche di amplificazione su campioni di urine o tamponi cervicali.…”

Self‐administered Vaginal Swabs Are a Feasible Alternative to Physician‐assisted Cervical Swabs for Sexually Transmitted Infection Screening in the Emergency Department

“…[2][3][4] Other studies (non-ED based) have shown that vaginal swab specimens perform as well as, or better than, urine or cervical samples for STI detection. [5][6][7] To the best of our knowledge, self-administered vaginal swabs (SAVS) have only been evaluated in non-ED settings. Our objective was to examine the feasibility of SAVS in identifying C. trachomatis and N. gonorrhoeae in female ED patients.…”