Impact of Trichomonas vaginalis transcription-mediated amplification-based analyte-specific-reagent testing in a metropolitan setting of high sexually transmitted disease prevalence

Abstract

Trichomoniasis is a significant sexually transmitted disease (STD) in the spectrum of public health and primary care because of its association with agents such as human immunodeficiency virus and Neisseria gonorrhoeae. However, its true significance may be underestimated due to diagnostic modalities that exhibit poor sensitivity. A total of 1,086 genital specimens from two urban emergency departments, a suburban urgent-care facility, and a metropolitan outpatient physician group were subjected to transcription-mediated amplification-based Trichomonas vaginalis analyte-specific-reagent (ASR) testing (Gen-Probe, Inc.). The rate of positive molecular ASR results (14.5%) doubled that of direct saline preparation (7.0%; P < 0.0002). Analogous increases were observed at one emergency department and within the outpatient physician group (P < 0.0002). No significant increase in the rate of positive molecular ASR results was observed from the facilities that encountered a lower frequency of black/African American patients. While positive T. vaginalis findings via direct saline preparation did not have a significant association with concomitant Chlamydia trachomatis or N. gonorrhoeae infection overall, a positive T. vaginalis ASR result was a better predictor of concomitant C. trachomatis or N. gonorrhoeae infection (odds ratios of 2.34 and 4.46, respectively; P < 0.0001). The increased rate of positive T. vaginalis ASR results was observed in both point-of-care (P = 0.02 versus direct saline preparation) and laboratory (P = 0.003) testing. Highly sensitive T. vaginalis molecular ASR not only transcends issues of specimen integrity and microscopic acumen but also has an increased ability to predict the likelihood of additional STDs in defined populations.

FIG. 1.

Race and ethnicity distribution in rank order five-digit ZIP code tabulation areas constituting the 70th percentile of health care encounters within the metropolitan outpatient physician group (A), urban emergency department A (B), suburban urgent-care facility (C), and urban emergency department B (D). Diagonally striped sections represent blacks/African Americans; vertically striped sections represent Hispanics/Latinos; horizontally striped sections represent Asians; dotted sections represent Caucasians; and solid sections represent other races or ethnicities.

FIG. 2.

Percentage of positive Trichomonas vaginalis results determined by direct saline preparation (open bars) and molecular ASR (solid bars) and stratified by health care entity for 1,086 female genital specimens. Asterisks denote P values of <0.0002.

FIG. 3.

Direct comparisons of Trichomonas vaginalis direct saline preparation and molecular ASR results, delineated by health care entity, in a retrospective evaluation of 1,086 primary genital specimens.