Trichomonas vaginalis Nucleic Acid Amplification Testing at an Urban HIV Clinic

Clinical Evaluation of the Alinity m STI Multiplex PCR Assay

BACKGROUND

Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are routinely tested and reported; however, Trichomonas vaginalis (TV) is the most common sexually transmitted infection (STI) in the United States and the prevalence of Mycoplasma genitalium (MG) infections is likely higher than estimated. We examined the clinical performance of the Alinity m STI assay for detection and surveillance of CT/NG/TV/MG in urine specimens from patients at a large academic medical center.

METHODS

Urine specimen from 198 patients was tested in this evaluation. Alinity m STI and Aptima Combo 2 CT/NG and TV assay (Panther System) results were compared, with discrepant results run on the cobas 6800 CT/NG, TV/MG assays. Analyzer turnaround times, time from loading the specimen on the analyzer to results reporting, were determined for Alinity m and Panther systems.

RESULTS

Overall percent agreements of the Alinity m in comparison with the Aptima and cobas assays for CT, NG, TV, and MG were 99.5% (97.2%, 99.9%), 99.5% (97.2%, 99.9%), 98.4% (95.5%, 99.5%), and 86.4% (66.7%, 95.3), respectively. There were 5 discrepant samples (CT, 1; NG, 1; TV, 3) between the Alinity m and the Aptima assays, and 3 MG discrepant samples between the Alinity m STI and cobas 6800. Two of the 5 Aptima and Alinity m discrepant samples were resolved as they yielded similar results on both Alinity m and cobas 6800. TV and MG infections comprised 54% of the positive samples and were more often asymptomatic than CT and NG infections. Analyzer turnaround time was 3 hours 25 minutes for the Aptima CT/NG, 3 hours 25 minutes for Aptima TV, and 1 hour 55 minutes for Alinity m STI assay.

CONCLUSIONS

The Alinity m STI assay allows for fast and simultaneous detection of the 4 major STI pathogens, which can facilitate surveillance and provide accurate results to help clinicians diagnose for initiation of appropriate treatment.

Construction a novel detection method for Trichomonas vaginalis based on recombinant enzyme polymerase amplification targeting the Actin gene

Trichomoniasis is a common and curable sexually transmitted disease worldwide. The rapid, convenient, and accurate diagnosis of trichomoniasis is an important link in the prevention and treatment of the disease. The current detection methods of Trichomonas vaginalis are mainly wet mount microscopy, culture, nested PCR, and loop-mediated isothermal amplification. However, these detection methods have some shortcomings. In this study, a recombinant enzyme polymerase amplification (RPA) assay had been conducted to detect T. vaginalis. The target gene and the corresponding primers were screened, and the reaction system and conditions were optimized in the assay of RPA. The sensitivity and specificity of this detection method were analyzed. The detection efficiency of wet mount microscopy, culture, nested PCR, and RPA was compared by testing 53 clinical samples from vaginal secretions. By screening, the actin gene of T. vaginalis could be used as a target gene for RPA detection of T. vaginalis, and the optimum reaction condition to amplify the actin gene by RPA was at 39°C for 30 min. The detection limit of T. vaginalis DNA using RPA was 1 pg, corresponding to a sensitivity of approximately five trophozoites. The RPA assay demonstrated high specificity for T. vaginalis, and there was no cross-reactivity with Giardia lamblia, Escherichia coli, Lactobacillus, Toxoplasma gondii, Staphylococcus aureus, and Candida albicans. Of the 53 clinical samples, the positive rates of T. vaginalis detected by wet mount microscopy, culture, nested PCR and RPA were 50.9 4% (27/53), 71.7% (38/53), 71.7% (38/53), and 69.81% (37/53), respectively. Compared with culture which was used as the gold standard for diagnosing trichomoniasis, testing clinical samples by wet mount microscopy showed 71.05% sensitivity, 100% specificity, and moderate diagnostic agreement with the culture (K = 0.581, Z = 4.661, p < 0.001). The nested PCR showed 100% sensitivity, 100% specificity, and excellent diagnostic agreement (K = 1, Z = 7.28, p < 0.001), while RPA displayed 97.37% sensitivity, 100% specificity, and excellent diagnostic agreement (K = 0.954, Z = 6.956, p < 0.001). At the present study, rapid amplification of actin gene by RPA could be used as a tool for detection of T. vaginalis. The detection method of RPA was more sensitive than wet mount microscopy and displayed excellent specificity. Moreover, RPA amplification of actin gene did not require a PCR instrument and the amplification time was shorter than that of ordinary PCR. Therefore, the RPA assay was proposed in this study as a point-of-care examination and a diagnostic method of T. vaginalis infection, which exhibited the potential value in the treatment and prevention of trichomoniasis.

Epidemiology, natural history, diagnosis, and treatment of Trichomonas vaginalis in men

Trichomonas vaginalis infections in men are traditionally considered to be benign and consequently have been overlooked. However, men with this common sexually transmitted infection can experience urethritis, prostatitis, reduced fertility, and amplified HIV risk. In addition, men are often asymptomatic and can unknowingly spread the infection to their female sexual partners. With advances in T. vaginalis diagnostics, more men are being diagnosed, yet the optimal method of treatment in men remains unknown. The purpose of this review is to discuss the epidemiology, natural history, diagnosis, and treatment of T. vaginalis among men.

Prevalence of Sexually Transmitted Infections and Human Immunodeficiency Virus in Transgender Persons: A Systematic Review

Purpose: Despite reportedly high rates of human immunodeficiency virus (HIV) and other sexually transmitted infections (STIs) among transgender people, laboratory-proven prevalence of these infections in this population has not been systematically reviewed. We performed a systematic review and meta-analysis of the medical literature involving laboratory-proven HIV and STI diagnoses among transgender people.

Methods: A systematic review of the English literature regarding laboratory-proven HIV and/or STI testing in transgender populations within the last 50 years was performed. Preliminary meta-analyses assessing the prevalence of HIV and STIs among both transgender men and transgender women were performed. Given the heterogeneity of included studies, these analyses were difficult to interpret and not included in our results.

Results: Our literature review identified 25 studies, representing 11 countries. All of these studies included transgender women, with 9 (36%) including data on transgender men. HIV was the most commonly studied STI, with prevalence ranging from 0% to 49.6% in transgender women and 0% to 8.3% in transgender men. For syphilis, gonorrhea, and chlamydia, respectively, prevalence ranged from 1.4% to 50.4%, 2.1% to 19.1%, and 2.7% to 24.7% in transgender women and from 0% to 4.2%, 0% to 10.5%, and 1.2% to 11.1% in transgender men. Site-specific testing practices for gonorrhea and chlamydia were variable. No studies reported prevalence data on trichomoniasis.

Conclusion: The literature describing STIs and transgender people primarily focuses on transgender women and HIV. Data involving HIV and STIs among transgender men are lacking. These findings highlight opportunities for the future study of epidemiology of HIV/STIs in transgender men and the relevance of STIs in transgender people.

Development of a convenient detection method for Trichomonas vaginalis based on loop-mediated isothermal amplification targeting adhesion protein 65

BACKGROUND

Trichomoniasis resulting from Trichomonas vaginalis (T. vaginalis) has been considered as a commonly seen disease with the transmission way of sex. At present, the detection methods of T. vaginalis mainly include wet mount microscopy, culture, PCR, immunofluorescence and ELISA. However, all of these detection methods exist shortcomings.

METHODS

In this study, a loop-mediated isothermal amplification (LAMP) assay that targeted the species-specific sequence of adhesion protein 65 (AP65) gene had been conducted to detect T. vaginalis. The optimum reaction system and conditions were optimized in this rapid detection method.

RESULTS

The results of sensitivity analysis showed that the LAMP assay targeting the AP65 gene was 1000 times more sensitive than the nested PCR targeting the actin gene commonly used for detection of T. vaginalis, and the detecting limitation of the former was 10 trichomonad. Moreover, the amplification of the target gene AP65 by LAMP assay exhibited high specificity and the product was exclusively from T. vaginalis. The detection technique of LAMP did not exhibit cross-reactivity with the common pathogens of Trichinella spiralis, Toxoplasma gondii, Escherichia coli, Candida albicans, Staphylococcus aureus, Haemophilus.

CONCLUSIONS

According to the present study, the LAMP assay with the target of AP65 gene, was suitable for the early diagnosis of T. vaginalis infections. Consequently, the LAMP assay was proposed by the current study as a point-of-care examination and an alternative molecular tool which exhibited the potential value in the treatment, control and prevention of trichomoniasis transmission and relevant complication.

Recent advances in the epidemiology, diagnosis, and management of Trichomonas vaginalis infection

Trichomonas vaginalis is the most common, curable non-viral sexually transmitted infection (STI) worldwide. Despite this burden of disease, it is not currently a reportable disease in the United States. Recent advances in the epidemiology, diagnosis, and management of T. vaginalis infection are described in this article. This includes updated global and U.S. prevalence data in women and men as well as recent epidemiological data in HIV-infected individuals and pregnant women. Advances in molecular diagnostics are also reviewed, as are data from recent clinical trials regarding the treatment of trichomonas in women.

Trichomonas vaginalis infection and the diagnostic significance of detection tests among Ghanaian outpatients

Background

There is little data on Trichomonas vaginalis infection in Ghana. This study evaluated the prevalence of trichomoniasis using different diagnostic methods and determined the risk factors for infection in patients.

Methods

A structured questionnaire was administered. Vaginal swabs, urethral swabs and urine specimens were obtained from consenting patients; and the samples processed following standard protocols. The presence of T. vaginalis was determined using wet mount microscopy and polymerase chain reaction (PCR) as gold standard. We also assessed the diagnostic performance the JD’s Trichomonas V® rapid antigen test to inform clinical practice.

Results

The PCR assay detected T. vaginalis positivity in 64 of 150 patients (42.6, 95%CI:35.0, 50.6) including all positive samples of wet mount microscopy and JD’s Trichomonas V® test. Wet mount microscopy showed low sensitivity (31.6%), high specificity (100%), moderate positive predictive value (75.0%), moderate positive likelihood ratio (3.0), and weak agreement (Cohen’s kappa, 0.283) with PCR assay. The JD’s Trichomonas V® test displayed lower sensitivity (25.0%), specificity (83.3%), and weaker measure of agreement (Cohen’s kappa, 0.233) with PCR. In multivariate analysis, the strongest independent predictor for T. vaginalis was female gender [adjusted odds ratio (AOR), 24.89; 95% confidence interval (CI): 10.58, 51.21; P-value< 0.001]. Knowledge of STI showed a protective effect against infection with the parasite (AOR, 0.13; 95%CI: 0.07, 0.29; P-value< 0.017).

Conclusion

The sensitivity of wet mount microscopy was low for T. vaginalis screening in our region. The JD’s Trichomonas V® test should not be considered as an alternative test. We recommend mandatory PCR assay for confirmation of negative wet mount results.

Incidence and predictors of reinfection with trichomoniasis based on nucleic acid amplification testing results in HIV-infected patients

Trichomonas vaginalis infection contributes to HIV transmission. The study objective was to determine the incidence and predictors of T. vaginalis reinfection among HIV-infected women in Birmingham, Alabama. A retrospective cohort study of women at an urban HIV clinic from August 2014 to March 2016 with T. vaginalis by nucleic acid amplification test (NAAT) was conducted. Time to first episode of reinfection was evaluated using Kaplan-Meier survival curves. The association of various predictors was evaluated by univariate and multivariable Cox proportional hazards analyses. Of 612 HIV-infected women at the UAB HIV clinic tested for T. vaginalis by the Aptima TV assay, 110 (18.0%) were identified with prevalent T. vaginalis infection. Overall, 25/110 (22.7%) had a first episode of T. vaginalis reinfection by NAAT with a rate of 3.7 reinfections per 100 person-months (95% confidence interval [CI]: 2.3, 5.2). In univariate analysis, only an HIV viral load (VL) ≥200 copies/ml approached statistical significance (hazard ratio = 2.26; 95% CI: 0.97, 5.29, p = 0.06). After adjusting for age and race, the association of HIV VL ≥200 copies/ml remained strong (adjusted hazard ratio = 2.49; 95% CI: 0.99, 6.27, p = 0.05). T. vaginalis reinfection was high among HIV-infected women in this sample, necessitating enhanced disease control efforts in this high-risk population.

Sexually Transmitted Infection Prevalence in Women With HIV: Is There a Role for Targeted Screening?

BACKGROUND

Rates of sexually transmitted infections (STIs) and HIV are highest in the southern United States but vary widely by sex, age, and risk behavior. Current guidelines recommend annual screening for chlamydia, gonorrhea, syphilis, and trichomoniasis in all sexually active women with HIV.

METHODS

Screening rates and test positivity for chlamydia, gonorrhea, syphilis, and trichomoniasis were determined per calendar year in this retrospective cohort study of women in care at an urban HIV clinic in Birmingham, Alabama, from 2013 to 2015. Chlamydia, gonorrhea, and trichomonas infections were detected by molecular diagnostics and syphilis by serology. A combined end point for chlamydia/gonorrhea/syphilis (STI-3) was created based on similar test positivity and predictors. Predictors of STI-3 were identified using logistic regression and generalized estimating equations.

RESULTS

Among 745 women with HIV, median age was 46.8 years, 78.8% were black, and 61% were sexually active. In 2015, 83.7% of women were tested for STI. Test positivity was 1.0% for chlamydia, 0.5% for gonorrhea, 1.6% for syphilis, and 13.3% for trichomoniasis. Independent predictors of STI-3 were recent chlamydia or gonorrhea (odds ratio [OR], 3.7; 95% confidence interval [CI], 1-13.4; P = 0.047), public insurance compared with private (OR, 3.5; CI, 1-11.8; P = 0.048), and sex after drugs/alcohol (OR, 3.0; CI, 1.2-8.0; P = 0.025). Women 50 years or older were less likely to have STI (OR, 0.3; CI, 0.1-1; P = 0.040).

CONCLUSIONS

In a cohort of women engaged in HIV care in the southern United States, detection of chlamydia, gonorrhea, and syphilis was infrequent but trichomoniasis was common. Many women screened for STI were low risk and universal testing strategies warrant evaluation.

Aptamer Selection against a Trichomonas vaginalis Adhesion Protein for Diagnostic Applications

Trichomoniasis, caused by Trichomonas vaginalis, is the leading nonviral sexually transmitted infection worldwide. We report the selection of a DNA aptamer against a T. vaginalis adhesion protein, AP65, using a microtiter plate-based in vitro combinatorial chemistry process termed systematic evolution of ligands by exponential enrichment. The enriched library pool was sequenced by next-generation sequencing, and several aptamer candidates with high affinity and specificity were identified. The aptamer with the highest affinity and specificity had a K_D in the low nanomolar range, as confirmed by three different techniques: surface plasmon resonance, enzyme-linked aptamer assay, and biolayer interferometry. The selected aptamer was demonstrated to have a high specificity to the AP65 protein and to T. vaginalis cells with no cross-reactivity to other enteric and urogenital microorganisms. Current work is focused on the development of inexpensive and easy-to-use aptamer-based diagnostic assays for the reliable and rapid detection of T. vaginalis in vaginal swabs.

Prevalence and Correlates of Trichomonas vaginalis Infection Among Men and Women in the United States

Background

The epidemiology of Trichomonas vaginalis (TV) infection in the United States is poorly defined.

Methods

Males and females aged 18-59 years who participated in the 2013-2014 National Health and Nutrition Examination Survey and provided a urine specimen were tested for TV infection (n = 4057). Participants were also examined for Chlamydia trachomatis (CT) infection, genital human papillomavirus (HPV) infection, and herpes simplex virus type 2 serostatus. Weighted adjusted prevalence ratios (aPRs) were estimated by multivariable Poisson regression.

Results

TV infection prevalence was 0.5% and 1.8% among males and females, respectively. TV infection prevalence was 4.2% among black males, 8.9% among black females, and 0.03% and 0.8%, respectively, among males and females of other races/ethnicities. TV infection prevalence (aPR [95% confidence interval]) was positively associated with female sex (6.1 [3.3-11.3]), black race (vs other races/ethnicities; 7.9 [3.9-16.1]), older age (vs 18-24 years; 3.0 [1.2-7.1] for 25- to 39-year-olds and 3.5 [1.3-9.4] for 40- to 59-year-olds), having less than a high school education (vs completing high school or more; 2.0 [1.0-4.1]), being below the poverty level (vs at or above the poverty level; 4.0 [2.1-7.7]), and having ≥2 sexual partners in the past year (vs 0-1 sexual partners; 3.6 [2.0-6.6]). There were no TV and CT coinfections. Genital HPV detection was not independently associated with TV infection. Among persons aged 18-39 years, there was a significant racial disparity in all sexually transmitted infections examined, and this disparity was greatest for TV infection.

Conclusions

There is a high and disproportionate burden of urinary TV infection in the adult civilian, noninstitutionalized black population in the United States that warrants intervention.

Budgetary Impact of Compliance With STI Screening Guidelines in Persons Living With HIV

INTRODUCTION

The 2015 Centers for Disease Control Sexually Transmitted Diseases Treatment Guidelines recommend annual screening of all people living with HIV (PLWH) for Neisseria gonorrhoeae, Chlamydia trachomatis, and syphilis; annual Trichomonas vaginalis screening is recommended for HIV-infected women. The study objective was to evaluate the budgetary impact of sexually transmitted infection (STI) screening. We hypothesized that recommended STI screening is costly and would not be covered in full by insurers.

METHODS

This cost analysis evaluates charges and reimbursement for recommended screening for the above 4 STIs. This study projects the net yield (reimbursement minus expenditures) of providing tests to eligible PLWH receiving care at an urban HIV clinic in Birmingham, AL. Four scenarios evaluated the net yield when different laboratory providers, rates of compliance, and Ryan White Program fund availability were examined.

RESULTS

The number of patients receiving care at our HIV clinic from August 2014 to August 2015 was 3163 (768 female and 2395 male patients). Annual screening for N. gonorrhoeae, C. trachomatis, syphilis, and T. vaginalis would lead to a mean net loss of $129,416, $118,304, $72,625, and $13,523, respectively. Most costly scenarios for a health system include the use of a regional laboratory (-$1,241,101) and lack of Ryan White HIV/AIDS Program funding (-$85,148).

DISCUSSION

Compliance with STI screening practices is costly. Sustainability will require critical analysis of true costs and cost-effectiveness of STI screening tests in PLWH. Providers, policy makers, and insurers each have a role in ensuring the provision of these evidence-based services to PLWH.