Rapid and point-of-care tests for the diagnosis of Trichomonas vaginalis in women and men

Independent clinic-based evaluation of point-of-care testing for the screening of Chlamydia trachomatis, Neisseria gonorrhoea and Trichomonas vaginalis in women-at-risk in Australia, Guatemala, Morocco, and South Africa

BACKGROUND

In 2018, the World Health Organization commenced a multi-country validation study of the Cepheid GeneXpert for a range of molecular-based point-of-care (POC) tests in primary care settings. One study arm focused on the evaluation of POC tests for screening 'women at risk' for chlamydia (CT), gonorrhoea (NG) and trichomonas (TV) in four countries - Australia, Guatemala, Morocco and South Africa.

METHODS

Study participants completed a pre-test questionnaire which included demographics, clinical information and general questions on POC testing (POCT). Two vaginal swab samples (either self-collected or clinician collected) from each patient were tested on the GeneXpert at the POC and at a reference laboratory using quality-assured nucleic acid amplification tests (NAATs).

RESULTS

One thousand three hundred and eighty-three women were enrolled: 58.6% from South Africa, 29.2% from Morocco, 6.2% from Guatemala, and 6.0% from Australia. 1296 samples for CT/NG and 1380 samples for TV were tested by the GeneXpert and the reference NAAT. The rate of unsuccessful tests on the GeneXpert was 1.9% for CT, 1.5% for NG and 0.96% for TV. The prevalence of CT, NG and TV was 31%, 13% and 23%, respectively. 1.5% of samples were positive for all three infections; 7.8% were positive for CT and NG; 2.4% were positive for NG and TV; and 7.3% were positive for CT and TV. Compared to reference NAATs, pooled estimates of sensitivity for the GeneXpert tests were 83.7% (95% confidence intervals 69.2-92.1) for CT, 90.5% (85.1-94.1) for NG and 64.7% (58.1-70.7) for TV (although estimates varied considerably between countries). Estimates for specificity were ≥96% for all three tests both within- and between-countries. Pooled positive and negative likelihood ratios were: 32.7 ([CI] 21.2-50.5) and 0.17 (0.08-0.33) for CT; 95.3 (36.9-245.7) and 0.10 (0.06-0.15) for NG; and 56.5 (31.6-101.1) and 0.35 (0.27-0.47) for TV.

CONCLUSION

This multi-country evaluation is the first of its kind world-wide. Positive likelihood ratios, as well as specificity estimates, indicate the GeneXpert POC test results for CT, NG and TV were clinically acceptable for ruling in the presence of disease. However, negative likelihood ratios and variable sensitivity estimates from this study were poorer than expected for ruling out these infections, particularly for TV.

TRIAL REGISTRATION

Ethics approval to conduct the ProSPeRo study was granted by the WHO Ethics Review Committee, as well as local ethics committees from all participating countries.

On The Horizon: Novel Approaches to Sexually Transmitted Infection Prevention

Rates of sexually transmitted infections (STIs), especially cases of infectious and congenital syphilis, are increasing in the United States. Novel strategies for STI prevention are being explored and include doxycycline post-exposure prophylaxis and the potential utility of vaccines against gonorrhea. Self-collection of samples and point of care testing for STI are increasingly being employed in a variety of settings. Both can improve uptake of screening and lead to earlier detection and treatment of incident STI in target populations. Overcoming existing regulatory issues and optimizing implementation of current evidence-based strategies will be key to maximizing future STI prevention efforts. Here we provide an update for primary care providers on selected new strategies for STI prevention either currently available or under development for possible future use.

Declining Prevalence of Trichomonas vaginalis Diagnosed by Wet Mount in a Cohort of U.S. Women With and Without HIV

Background: Women living with HIV (WLWH) are often coinfected with Trichomonas vaginalis (TV), and annual screening is recommended. Our goal was to assess differences in TV prevalence at study entry and over time in enrollment cohorts of the Women's Interagency HIV Study. Methods: In a multisite study, TV was diagnosed by wet mount microscopy. Prevalence was determined across four enrollment waves: 1994-1995, 2001-2002, 2011-2012, and 2013-2015. Generalized estimating equation multivariable logistic regression models assessed changes in visit prevalence across waves after controlling for HIV disease severity and other risks. Results: At 63,824 person-visits (3,508 WLWH and 1,262 women without HIV), TV was diagnosed by wet mount at 1979 visits (3.1%). After multivariable adjustment, HIV status was not associated with TV detection, which was more common among younger women, women with multiple partners, and irregular condom use. All enrollment waves showed a decline in TV detection over time, although p-value for trend did not reach significance for most recent waves. To explore the potential utility of screening among WLWH, we assessed rates of TV detection among women without appreciable vaginal discharge on examination. Initial TV prevalence among asymptomatic women was 3.5%, and prevalence decreased to 0.5%-1% in the most recent wave (2013-2015) (p-trend <0.0001). Conclusions: In this cohort, TV rates are low among WLWH, and HIV does not increase TV risk. Screening may benefit newly diagnosed WLWH, women with risk factors, or those receiving care sporadically but is unlikely to further reduce the low rate of TV among women in care, especially older women without multiple partners. The clinical trials registration number for WIHS is NCT00000797.

The Past, Present, and Future in the Diagnosis of a Neglected Sexually Transmitted Infection: Trichomoniasis

More than one million curable sexually transmitted infections occur every day. Trichomonas vaginalis is one of the main infections responsible for these epidemiological data; however, the diagnosis of this protozoan is still mainly based on microscopic and culture identification. The commercialization of immunological tests and the development of molecular techniques have improved the sensitivity of classical methods. Nevertheless, the fact that trichomoniasis is a neglected parasitic infection hinders the development of novel techniques and their implementation in routine diagnosis. This review article shows the different methods developed to identify T. vaginalis in population and the difficulties in diagnosing male and asymptomatic patients. The importance of including this parasite in routine gynecological screening, especially in pregnant women, and the importance of considering T. vaginalis as an indicator of high-risk sexual behavior are also discussed.

Persistent Trichomonas vaginalis infections and the pseudocyst form

Recent studies have proposed that Trichomonas vaginalis, the causative agent of trichomoniasis [the most common nonviral sexually transmitted infection (STI) in humans] can establish persistent infections in the vagina. T. vaginalis infections are often asymptomatic but can have adverse consequences such as increased risk of HIV-1 infection and cervical cancer. Despite this, it remains an understudied infection. A potential agent of persistent infections is the 'pseudocyst', a spherical form of T. vaginalis identified by several laboratories and linked to persistence in related species such as the avian parasite Trichomonas gallinae and cattle parasite Tritrichomonas foetus. Additional robust and reproducible research on pseudocysts and persistent T. vaginalis infections is required, which may ultimately shed light on how to better diagnose and treat trichomoniasis.

[Urethritis-spectrum of pathogens, diagnostics and treatment]

A broad spectrum of bacteria, fungi, protozoa and viruses can cause urethritis. In particular, N. gonorrhoeae, C. trachomatis, M. genitalium and T. vaginalis are the focus of diagnostic considerations as classic pathogens associated with sexually transmitted infections (STI). A step-by-step procedure is needed to make a definitive diagnosis. Microscopy with a staining preparation provides an initial differentiation between gonoccocal and non-gonococcal urethritis in symptomatic men as a point-of-care (POC) test. Nucleic acid amplification technology (NAAT) is used for specific and sensitive pathogen detection and, as a multiplex diagnostic test, offers the possibility of detecting several organisms from the same sample. In addition, compared to culture, no vital organisms are required, which allows the collection and use of more diverse and less invasive biological samples (e.g. first stream urine in men or vaginal swabs). Susceptibility testing by culture remains essential for N. gonorrhoeae as resistance is emerging. The treatment of urethritis depends on the suspected or proven pathogen according to the current guidelines. Treatment failure can be caused by many factors (coinfection, lack of therapy adherence, reinfection or resistance of the pathogen) and requires a repeated diagnostic and therapeutic procedure and differentiated approach.

Flexible and Innovative Connectivity Solution to Support National Decentralized Infectious Diseases Point-of-Care Testing Programs in Primary Health Services: Descriptive Evaluation Study

BACKGROUND

Molecular point-of-care (POC) testing for Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Trichomonas vaginalis (TV) has been available in regional and remote primary health services in Australia as part of a decentralized POC testing program since 2016 and for SARS-CoV-2 from 2020. As there was no suitable existing connectivity infrastructure to capture and deliver POC test results to a range of end users, a new system needed to be established.

OBJECTIVE

The aim of the study is to design, implement, and optimize a connectivity system to meet clinical management, analytical quality management, and public health surveillance needs.

METHODS

We used commercially available e-messaging technology coupled with adapted proprietary software to integrate a decentralized molecular POC testing platform (GeneXpert) in primary health services and interface with end-user databases. This connectivity infrastructure was designed to overcome key barriers to the implementation, integration, and monitoring of these large multijurisdictional infectious disease POC testing networks. Test result messages were tailored to meet end-user needs. Using centrally captured deidentified data, we evaluated the time to receipt of test results and completeness of accompanying demographic data.

RESULTS

From January 2016 to April 2020, we operationalized the system at 31 health services across 4 jurisdictions and integrated with 5 different patient management systems to support the real-time delivery of 29,356 CT/NG and TV test results to designated recipients (patient management system and local clinical and central program databases). In 2019, 12,105 CT/NG and TV results were delivered, and the median time to receipt of results was 3.2 (IQR 2.2-4.6) hours, inclusive of test runtime. From May 2020 to August 2022, we optimized the system to support rapid scale-up of SARS-CoV-2 testing (105 services; 6 jurisdictions; 71,823 tests) and additional sexually transmissible infection testing (16,232 tests), including the electronic disease-specific notifications to jurisdictional health departments and alerts for connectivity disruption and positive results. In 2022, 19,355 results were delivered with an overall median transmission time of 2.3 (IQR 1.4-3.1) hours, 2.2 (IQR 1.2-2.3) hours for SARS-CoV-2 (n=16,066), 3.0 (IQR 2.0-4.0) hours for CT/NG (n=1843), and 2.6 (IQR 1.5-3.8) hours for TV (n=1446). Demographic data (age, sex, and ethnicity) were completed for 99.5% of test results in 2022.

CONCLUSIONS

This innovative connectivity system designed to meet end-user needs has proven to be sustainable, flexible, and scalable. It represents the first such system in Australia established independent of traditional pathology providers to support POC testing in geographically dispersed remote primary health services. The system has been optimized to deliver real-time test results and has proven critical for clinical, public health, and quality management. The system has significantly supported equitable access to rapid diagnostics for infectious diseases across Australia, and its design is suitable for onboarding other POC tests and testing platforms in the future.

Point-of-Care Testing for Sexually Transmitted Infections

Point-of-care testing for sexually transmitted infections is essential for controlling transmission and preventing sequelae in high-risk populations. Since the World Health Organization published the ASSURED criteria, point-of-care testing has improved for use in large population screening and rapid testing that prevents loss of clinical follow-up. Recent advancements have been advantageous for low-resource areas allowing testing at a minimal cost without reliable electricity or refrigeration. Point-of-care nucleic acid detection and amplification techniques are recommended, but are often inaccessible in low-resource areas. Future advancements in point-of-care diagnostic testing should focus on improving antibody-based assays, monitoring viral loads, and detecting antimicrobial resistance.

Investigating point-of-care diagnostics for sexually transmitted infections and antimicrobial resistance in antenatal care in Zimbabwe (IPSAZ): protocol for a mixed-methods study

INTRODUCTION

Sexually transmitted infections (STIs) can cause serious morbidity, including pelvic inflammatory disease, and adverse pregnancy outcomes. In low/middle-income countries, limited laboratory infrastructure has resulted in a syndrome-based approach being used for management of STIs, which has poor sensitivity and specificity, leading to considerable underdiagnosis and overtreatment. The WHO has called for development and evaluation of strategies to inform replacement of syndromic management by diagnostic testing.The aim of this project is to evaluate a strategy of point-of-care testing for six STIs in antenatal care (ANC) in Zimbabwe.

METHODS AND ANALYSIS

A prospective interventional study will be conducted in ANC clinics in Harare province, Zimbabwe. One thousand pregnant women will be recruited when registering for routine ANC. Alongside routine HIV and syphilis testing, participants will be offered an integrated screening package including testing for Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Trichomonas vaginalis (TV) and hepatitis B. All individuals with STIs will receive treatment, partner notification services, risk reduction counselling and referral if needed according to national guidelines. Gonorrhoea samples will be cultured and tested for antimicrobial resistance as per WHO enhanced gonococcal antimicrobial surveillance programme guidelines.The primary outcome measure is the composite prevalence of CT, NG, TV, syphilis and hepatitis B. A mixed-methods process evaluation and economic evaluation will be conducted to understand the acceptability, feasibility and cost-effectiveness of integrated STI testing, compared with standard of care (syndromic management).

ETHICS AND DISSEMINATION

The study protocol was approved by the Medical Research Council of Zimbabwe, the Biomedical Research and Training Institute Institutional Review Board, and the London School of Hygiene & Tropical Medicine Research Ethics Committee. Results will be submitted to open-access peer-reviewed journals, presented at academic meetings and shared with participating communities and with national and international policymaking bodies.

TRIAL REGISTRATION NUMBER

NCT05541081.

Will Antigen Testing Remain Relevant in the Point-of-Care Testing Environment?

Before the molecular age, cell culture was the gold standard for confirmatory diagnosis of viral and atypical infectious diseases. Typical cell culture methodologies are costly, require days (or weeks) for results, and require significant technical expertise. As a result, cell culture is impractical for timely diagnostic testing in most of the health care environments. Traditional bacterial culture methods, also have disadvantages due to the need for incubation, subsequent identification of pathogens, and significant technical expertise. This article discusses the general considerations of antigen and molecular assays and the merits and factors to consider when implementing diagnostic assays for several common pathogens.

Impact of Point-of-Care Testing on the Management of Sexually Transmitted Infections in South Africa: Evidence from the HVTN702 Human Immunodeficiency Virus Vaccine Trial

BACKGROUND

Alternative approaches to syndromic management are needed to reduce rates of sexually transmitted infections (STIs) in resource-limited settings. We investigated the impact of point-of-care (POC) versus central laboratory-based testing on STI treatment initiation and STI adverse event (STI-AE) reporting.

METHODS

We used Kaplan-Meier and Cox regression models to compare times to treatment initiation and STI-AE reporting among HVTN702 trial participants in South Africa. Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) were diagnosed POC at eThekwini clinic and in a central laboratory at Verulam/Isipingo clinics. All clinics used POC assays for Trichomonas vaginalis (TV) testing.

RESULTS

Among 959 women (median age, 23 [interquartile range, 21-26] years), median days (95% confidence interval [95%CI]) to NG/CT treatment initiation and NG/CT-AE reporting were 0.20 (.16-.25) and 0.24 (.19-.27) at eThekwini versus 14.22 (14.12-15.09) and 15.12 (13.22-21.24) at Verulam/Isipingo (all P < .001). Median days (95%CI) to TV treatment initiation and TV-AE reporting were 0.17 (.12-.27) and 0.25 (.20-.99) at eThekwini versus 0.18 (.15-.2) and 0.24 (.15-.99) at Verulam/Isipingo (all P > .05). Cox regression analysis revealed that NG/CT treatment initiation (adjusted hazard ratio [aHR], 39.62 [95%CI, 15.13-103.74]) and NG/CT-AE reporting (aHR, 3.38 [95%CI, 2.23-5.13]) occurred faster at eThekwini versus Verulam/Isipingo, while times to TV treatment initiation (aHR, 0.93 [95%CI, .59-1.48]) and TV-AE reporting (aHR, 1.38 [95%CI, .86-2.21]) were similar.

CONCLUSIONS

POC testing led to prompt STI management with potential therapeutic and prevention benefits, highlighting its utility as a diagnostic tool in resource-limited settings.

Assessment of Urinary Biomarkers for Infectious Diseases Using Lateral Flow Assays: A Comprehensive Overview

Screening of biomarkers is a powerful approach for providing a holistic view of the disease spectrum and facilitating the diagnosis and prognosis of the state of infectious diseases. Unaffected by the homeostasis mechanism in the human body, urine accommodates systemic changes and reflects the pathophysiological condition of an individual. Easy availability in large volumes and non-invasive sample collection have rendered urine an ideal source of biomarkers for various diseases. Infectious diseases may be communicable, and therefore early diagnosis and treatment are of immense importance. Current diagnostic approaches preclude the timely identification of clinical conditions and also lack portability. Point-of-care (POC) testing solutions have gained attention as alternative diagnostic measures due to their ability to provide rapid and on-site results. Lateral flow assays (LFAs) are the mainstay in POC device development and have attracted interest owing to their potential to provide instantaneous results in resource-limited settings. The discovery and optimization of a definitive biomarker can render POC testing an excellent platform, thus impacting unwarranted antibiotic administration and preventing the spread of infectious diseases. This Review summarizes the importance of urine as an emerging biological fluid in infectious disease research and diagnosis in clinical settings. We review the academic research related to LFAs. Further, we also describe commercial POC devices based on the identification of urinary biomarkers as diagnostic targets for infectious diseases. We also discuss the future use of LFAs in developing more effective POC tests for urinary biomarkers of various infections.

Point-of-Care Diagnostic for Trichomonas vaginalis, the Most Prevalent, Non-Viral Sexually Transmitted Infection

A point-of-care (POC) diagnostic is needed for both women and men to establish universal screening and surveillance for the number one, non-viral sexually transmitted infection (STI) caused by Trichomonas vaginalis. We developed a POC diagnostic for this STI using the MedMira Rapid Vertical Flow (RVF^®) Technology test cartridge with a membrane that includes a Vertical procedural/reagent control line (referred to as CVL) and spotted with 1 µg of a 72.4-kDa truncated version of α-actinin called ACT::SOE3. This protein is a specific diagnostic target for antibody in sera of individuals with trichomoniasis. Serum antibody to ACT::SOE3 is a positive reaction with the test spot. Specificity of ACT::SOE3 was revealed with monoclonal antibodies (MAbs) generated to ACT::SOE3. Addition of negative control serum with MAb 67B reactive to ACT::SOE3 shows detection of both ACT::SOE3 and the CVL. Only positive sera of individuals had antibody reactive with ACT::SOE3 and detected the presence of the spot and the CVL. Negative control sera were unreactive with ACT::SOE3 and only showed the presence of the CVL. Importantly, to show proof-of-principle for POC application, ACT::SOE3 was detected with the positive patient sera spiked with whole blood. Finally, packaged cartridges stored with desiccant packs at 37 °C for one year gave identical results with the positive and negative human sera. Our results show the validity of this new POC serodiagnostic for this STI.

Cost-effectiveness analysis of different screening and diagnostic strategies for sexually transmitted infections and bacterial vaginosis in women attending primary health care facilities in Cape Town

Background

Genital inflammation associated with sexually transmitted infections (STIs) and bacterial vaginosis (BV) is considered a key driver in the HIV epidemic. A new rapid point-of-care test (POC) that detects genital inflammation in women-Genital InFlammation Test (GIFT)-was recently developed by researchers at the University of Cape Town. The objective of this study was to establish the cost-effectiveness of this novel intervention relative to other relevant screening and diagnostic strategies for the management of STIs and BV in women seeking care in the public health sector in South Africa.

Methods

A decision analysis model was developed for five different screening and diagnostic strategies for women incorporating syndromic management, screening with GIFT and using etiological diagnosis. A decision tree was constructed using Microsoft Excel Office 365, and cost and effectiveness parameters were obtained from published literature and market prices. The model incorporated all clinic-level and treatment costs associated with diagnosing and treating a single episode of disease. The effectiveness of each approach was proxied by its sensitivity. One-way and threshold sensitivity analyses were conducted to test key uncertainties and assumptions in the model.

Results

Screening with GIFT, and following with antibiotic treatment according to syndromic management guidelines for GIFT-positive cases, was the most cost-effective strategy with an incremental cost-effectiveness ratio (ICER) of USD 11.08 per women diagnosed with an STI(s) and/or BV and provided treatment. This strategy resulted in lower rates of overtreatment compared to syndromic management, but higher rates compared to etiological diagnosis using nucleic acid amplification tests and microscopy. However, following a GIFT positive test with etiological diagnosis prior to treatment did not increase the effectiveness, but dramatically increased the cost.

Conclusion

Screening with GIFT and treating positive cases according to syndromic management guidelines is the most cost-effective strategy for the management of STIs and BV. GIFT has a potential to significantly improve the management of STIs and BV in women by identifying asymptomatic women and reducing their risk of HIV infection. This analysis presents a first step in establishing the cost-effectiveness of these interventions and paves the way for further research to develop optimal context-specific implementation strategies.

Detection of Trichomonas vaginalis Infection in Chronic Prostatitis/Chronic Pelvic Pain Syndrome Patients by Rapid Immunochromatographic Test

This study aims to evaluate associations between the immunochromatographic rapid test technique and Trichomonas vaginalis (TV) infection in patients with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) in Taiwan. All patients received post-prostate massage urine (VB3) Trichomonas rapid tests. The demographic characteristics and urogenital symptoms of CP/CPPS were recorded. Routine urinalysis of VB3 was also performed, and laboratory examination results of semen were recorded if available. A total of 29 patients with TV infection and 109 without TV infection were enrolled, which reflected that the prevalence in patients with TV infection was approximately 21%. Patients with TV infection displayed a significantly higher frequency of suprapubic/lower abdominal pain (p = 0.034), semen leukocyte > 5/high-power field (HPF) (p = 0.020), and an inflammatory type (category IIIA) (p = 0.005) than patients without TV infection. A higher prevalence of TV infection was found in patients with category IIIA (47.37%). No significant difference was found in the symptom duration and other clinical symptoms. In conclusion, the high prevalence of TV infection was revealed in CP/CPPS patients using the VB3 rapid Trichomonas test, especially in CP/CPPS patients with category IIIA. Thus, rapid TV testing might be vital for CP/CPPS patients in the hospital.

British Association for Sexual Health and HIV (BASHH) United Kingdom national guideline on the management of Trichomonas vaginalis 2021

The main objective of this guideline is to assist practitioners in managing individuals diagnosed with Trichomonas vaginalis (TV). It offers recommendations on the diagnostic tests, treatment regimens and health promotion principles needed for the effective management of TV. It covers the management of the initial presentation, as well as how to prevent transmission and future re-infection. It is aimed primarily at people aged 16 years or older presenting to health care professionals, working in departments offering specialist care in sexually transmitted infection (STI) management within the United Kingdom. However, the principles of the recommendations are applicable across all levels of STI care providers (N.B. non-specialist services may need to develop, where appropriate, local care pathways).

Diagnosis and Management of Trichomonas vaginalis: Summary of Evidence Reviewed for the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infections Treatment Guidelines

Trichomonas vaginalis is likely the most prevalent nonviral sexually transmitted infection, affecting an estimated 3.7 million women and men in the United States. Health disparities are prominent in the epidemiology of trichomoniasis, as African Americans are >4 times more likely to be infected than persons of other races. Since publication of the 2015 Centers for Disease Control and Prevention sexually transmitted diseases treatment guidelines, additional data have bolstered the importance of T. vaginalis infection sequelae in women, including increased risk of human immunodeficiency virus (HIV) acquisition, cervical cancer, preterm birth, and other adverse pregnancy outcomes. Less is known about the clinical significance of infection in men. Newly available diagnostic methods, including point-of-care assays and multiple nucleic acid amplification tests, can be performed on a variety of genital specimens in women and men, including urine, allowing more accurate and convenient testing and screening of those at risk for infection. Repeat and persistent infections are common in women; thus, rescreening at 3 months after treatment is recommended. In vitro antibiotic resistance to 5-nitroimidazole in T. vaginalis remains low (4.3%) but should be monitored. High rates of T. vaginalis among sexual partners of infected persons suggest a role for expedited partner treatment. A randomized controlled trial in HIV-uninfected women demonstrated that multidose metronidazole 500 mg twice daily for 7 days reduced the proportion of women with Trichomonas infection at 1 month test of cure compared with women receiving single-dose therapy (2 g). The 2-g single-dose oral metronidazole regimen remains the preferred treatment in men.

Evaluation and Management of Vaginitis

Vaginitis is a common concern for women across the lifespan. Vaginal symptoms may impact quality of life, and clinicians are challenged in the evaluation and management of bacterial vaginosis, Candida vaginitis, trichomoniasis, desquamative inflammatory vaginitis, and genitourinary syndrome of menopause.

Bridging the gap between development of point-of-care nucleic acid testing and patient care for sexually transmitted infections

The incidence rates of sexually transmitted infections (STIs), including the four major curable STIs - chlamydia, gonorrhea, trichomoniasis and, syphilis - continue to increase globally, causing medical cost burden and morbidity especially in low and middle-income countries (LMIC). There have seen significant advances in diagnostic testing, but commercial antigen-based point-of-care tests (POCTs) are often insufficiently sensitive and specific, while near-point-of-care (POC) instruments that can perform sensitive and specific nucleic acid amplification tests (NAATs) are technically complex and expensive, especially for LMIC. Thus, there remains a critical need for NAAT-based STI POCTs that can improve diagnosis and curb the ongoing epidemic. Unfortunately, the development of such POCTs has been challenging due to the gap between researchers developing new technologies and healthcare providers using these technologies. This review aims to bridge this gap. We first present a short introduction of the four major STIs, followed by a discussion on the current landscape of commercial near-POC instruments for the detection of these STIs. We present relevant research toward addressing the gaps in developing NAAT-based STI POCT technologies and supplement this discussion with technologies for HIV and other infectious diseases, which may be adapted for STIs. Additionally, as case studies, we highlight the developmental trajectory of two different POCT technologies, including one approved by the United States Food and Drug Administration (FDA). Finally, we offer our perspectives on future development of NAAT-based STI POCT technologies.

Trichomoniasis, a new look at a common but neglected STI in African descendance population in the United States and the Black Diaspora. A review of its incidence, research prioritization, and the resulting health disparities

Structural racism plays a significant role in limited access to higher education, financial resources, employment opportunities, and high-quality healthcare for African Americans. The lack of healthcare equity and infrastructure has directly contributed to overall poor healthcare outcomes for the Black community. Studies have shown that adverse health outcomes such as sexually transmitted diseases (STDs) are more prevalent in African Americans, regardless of their socioeconomic factors and lifestyles. For example, trichomoniasis, transmitted sexually by its etiological agent, Trichomonas vaginalis (T. vaginalis), predisposes those infected to co-infections with other STDs, such as human immunodeficiency virus (HIV), herpes, and other related infections. Our review showcases the impact of trichomoniasis on the health of the Black community with an emphasis on African American women. A critical examination of the socio-demographic history of Black people in the United States (US) is vital to illustrate the origin of past and current racial health disparities. Further, we expand the complex and nuanced conversation on the intersectionality of racism, health equity, and innovative epidemiological and biomedical research strategies needed to eradicate this global public health threat.

Identifying youth at high risk for sexually transmitted infections in community-based settings using a risk prediction tool: a validation study

BACKGROUND : Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are the most common bacterial sexually transmitted infections (STIs) worldwide. In the absence of affordable point-of-care STI tests, WHO recommends STI testing based on risk factors. This study aimed to develop a prediction tool with a sensitivity of > 90% and efficiency (defined as the percentage of individuals that are eligible for diagnostic testing) of < 60%.

METHODS

This study offered CT/NG testing as part of a cluster-randomised trial of community-based delivery of sexual and reproductive health services to youth aged 16-24 years in Zimbabwe. All individuals accepting STI testing completed an STI risk factor questionnaire. The outcome was positivity for either CT or NG. Backwards-stepwise logistic regression was performed with p ≥ 0.05 as criteria for exclusion. Coefficients of variables included in the final multivariable model were multiplied by 10 to generate weights for a STI risk prediction tool. A maximum likelihood Receiver Operating Characteristics (ROC) model was fitted, with the continuous variable score divided into 15 categories of equal size. Sensitivity, efficiency and number needed to screen were calculated for different cut-points.

RESULTS

From 3 December 2019 to 5 February 2020, 1007 individuals opted for STI testing, of whom 1003 (99.6%) completed the questionnaire. CT/NG prevalence was 17.5% (95% CI 15.1, 19.8) (n = 175). CT/NG positivity was independently associated with being female, number of lifetime sexual partners, relationship status, HIV status, self-assessed STI risk and past or current pregnancy. The STI risk prediction score including those variables ranged from 2 to 46 with an area under the ROC curve of 0.72 (95% CI 0.68, 0.76). Two cut-points were chosen: (i) 23 for optimised sensitivity (75.9%) and specificity (59.3%) and (ii) 19 to maximise sensitivity (82.4%) while keeping efficiency at < 60% (59.4%).

CONCLUSIONS

The high prevalence of STIs among youth, even in those with no or one reported risk factor, may preclude the use of risk prediction tools for selective STI testing. At a cut-point of 19 one in six young people with STIs would be missed.

How Could POCT be a Useful Tool for Migrant and Refugee Health?

Point of care testing (POCT) represents an important step forward in the clinical management of patients. POC assays are easy to use and do not require skilled personnel; therefore they are particularly useful in low resource settings where diagnostics laboratories equipped with complex instruments that require well trained technicians are not available. Samples can be processed immediately overcoming the problems related to the stability of the sample, storage and shipping to a centralized laboratory hospital based. Furthermore, results are delivered in real-time, usually less than 1 hr; thus, a clinical decision can be taken earlier. A prompt diagnosis is crucial in the case of contagious diseases allowing a rapid isolation of the infected patient and treatment; thus, reducing the risk of transmission of the pathogen. In this report, we address the use of POC assays in the diagnosis of infectious pathogens including hepatitis B and C viruses, human immunodeficiency virus-type 1, human papillomavirus, chlamydia trachomatis, neisseria gonorrhea, trichomonas vaginalis, mycobacterium tuberculosis and the parasite plasmodium. These pathogens are commonly detected among vulnerable people such as refugees and migrants. The described POC assays are based on nuclei acid amplification technology (NAAT) that is generally characterized by a high sensitivity and specificity.

Global prevalence of Trichomonas vaginalis among female sex workers: a systematic review and meta-analysis

Trichomoniasis is a sexually transmitted infection (STI), caused by the protozoan parasite, Trichomonas vaginalis. Female sex workers are intensely affected by the infection, since they have frequent direct physical contact. The current systematic review and meta-analysis represents the global prevalence of T. vaginalis in female sex workers. Five databases (Science Direct, Scopus, PubMed, Web of Science, and Google Scholar) were explored for literatures that published from July 1985 to June 2020. Totally, 85 studies (54,515 participants) from 46 countries met the inclusion criteria. The global pooled prevalence of T. vaginalis was 16% (95% CI 13-19%). The estimated pooled prevalence based on methods including wet mount, culture, and molecular techniques was 15% (95% CI 12-19%), 16% (95% CI 10-24%), and 22% (95% CI 13-32%), respectively. Moreover, the infection was most prevalent at the mean age of 30-36 (20%, 95% CI 11-30%). Regarding the World Health Organization (WHO) regions, the highest pooled prevalence was estimated to be in the African region (23%, 95% CI 7-46%). In addition, we indicated that countries with low-income level have the highest pooled prevalence (23%, 95% CI 14-34%). Our results revealed that the worldwide prevalence of T. vaginalis was significant in female sex workers. Therefore, considering a precise strategy such as a health education program with regard to safe intercourse is needed to increase knowledge and prevent T. vaginalis infection in sex workers.

HIV susceptibility in women: The roles of genital inflammation, sexually transmitted infections and the genital microbiome

Given that heterosexual transmission of HIV across the genital mucosa is the most common route of infection in women, an in-depth understanding of the biological mechanisms associated with HIV risk in the female genital tract (FGT) is essential for effective control of the epidemic. Genital pro-inflammatory cytokines are well-described biological co-factors to HIV risk. Increased levels of pro-inflammatory cytokines in the FGT have been associated with a 3-fold higher-risk of acquiring HIV, presumably through involvement in barrier compromise and the recruitment of highly activated HIV target cells to the site of initial viral infection and replication. Sexually transmitted infections (STIs) and bacterial vaginosis (BV) are suggested possible contributors to genital inflammation in the FGT, and this, coupled with the relationship between genital inflammation and HIV risk, underscores the importance of effective treatment of STI and BV in the promotion of women's health. In most low- and middle-income countries, STIs are treated syndromically, a practice providing rapid treatment without identifying the infection source. However, this approach has been associated with over-diagnosis and the overuse of drugs. Further, because many women with STIs are asymptomatic, syndromic management also fails to treat a vast proportion of infected women. Although several studies have explored the role of STIs and the vaginal microbiome on genital inflammation and HIV risk, the impact of STI and BV management on genital inflammation remains poorly understood. This review aimed to collate the evidence on how BV and STI management efforts affect genital inflammation and the genital microbiome in women.

Current and Future Trends in the Laboratory Diagnosis of Sexually Transmitted Infections

Sexually transmitted infections (STIs) continue to exert a considerable public health and social burden globally, particularly for developing countries. Due to the high prevalence of asymptomatic infections and the limitations of symptom-based (syndromic) diagnosis, confirmation of infection using laboratory tools is essential to choose the most appropriate course of treatment and to screen at-risk groups. Numerous laboratory tests and platforms have been developed for gonorrhea, chlamydia, syphilis, trichomoniasis, genital mycoplasmas, herpesviruses, and human papillomavirus. Point-of-care testing is now a possibility, and microfluidic and high-throughput omics technologies promise to revolutionize the diagnosis of STIs. The scope of this paper is to provide an updated overview of the current laboratory diagnostic tools for these infections, highlighting their advantages, limitations, and point-of-care adaptability. The diagnostic applicability of the latest molecular and biochemical approaches is also discussed.

Point-of-Care Testing for Sexually Transmitted Infections: A Review of Recent Developments

CONTEXT.—

Sexually transmitted infections (STIs) are among the most common communicable diseases globally and are associated with significant morbidity and mortality worldwide. Point-of-care tests have the potential to revolutionize the prevention and control of STIs by enabling rapid diagnosis and early treatment of infections, thus interrupting transmission and preventing the sequelae of untreated infections. Currently, there are several point-of-care (POC) tests available for the diagnosis of Treponema pallidum, Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis infections, although these tests differ with regard to their performance, turnaround time, and cost.

OBJECTIVE.—

To provide an updated review of the POC tests available and under development for the diagnosis of T pallidum, C trachomatis, N gonorrhoeae, and T vaginalis infections, to discuss the context for which these tests might be used, and to highlight future directions for test development.

DATA SOURCES.—

We reviewed the literature pertaining to the recent development and performance evaluations of POC tests for the diagnosis of syphilis, chlamydia, gonorrhea, and trichomonas.

CONCLUSIONS.—

Recently, there has been rapid development of new POC tests for STIs. Although there are inexpensive, rapid, and accurate POC tests available for syphilis, there are few such tests available for the diagnosis of chlamydia, gonorrhea, or trichomonas, and currently none with the ability to detect antimicrobial resistance in N gonorrhoeae. Research evaluating implementation strategies for the currently available tests and the development of additional POC tests that are rapid, accurate, and affordable are urgently needed to address the rising number of STIs worldwide.

Sexually Transmitted Infections Part 2: Discharge Syndromes and Pelvic Inflammatory Disease

Sexually transmitted infections (STIs) disproportionately affect young people, with more than half of the infections occurring in youth aged 15 to 25 years. (1)(2) This review, the second in a 2-part series on STIs, focuses on infections that may cause abnormal vaginal or penile discharge, including trichomonas, chlamydia, gonorrhea, and pelvic inflammatory disease (PID). Most infected persons, however, are asymptomatic. Nucleic acid amplification tests are the most sensitive and specific for the detection of chlamydia, gonorrhea, and trichomoniasis, and they can be performed on provider- or patient-collected swabs. Providers should have a low threshold for diagnosing and treating PID because untreated PID can have serious long-term complications for young women. Indications for hospitalization for PID include the presence of a tubo-ovarian abscess, severe illness with systemic symptoms, pregnancy, human immunodeficiency virus infection, and failure to respond to outpatient oral treatment (within 48-72 hours) or inability to tolerate the oral treatment.

Performance evaluation and acceptability of point-of-care Trichomonas vaginalis testing in adult female emergency department patients

We evaluated the accuracy and perception of a patient self-administered, tablet-facilitated rapid Trichomonas vaginalis (TV) point-of-care (POC) test in adult female emergency department (ED) patients.ED patients undergoing gynecologic examination were eligible. Each consented participant self-collected a vaginal swab, performed a tablet-facilitated TV rapid test using the OSOM® Trichomonas Rapid Test, and completed pre- and post-test self-surveys. After the self-test, the clinician collected one standard-of-care (SOC) vaginal swab for wet-mount testing and two for research. The research coordinator performed the TV rapid test using the clinician-collected swab, and reported the results to the clinician and patient. If the self- and coordinator-performed results were discordant, a TV nucleic acid amplification test (NAAT) was performed in a clinical laboratory. A survey was later administered to providers to assess their perceptions of the utility of the POC TV test.Of the 136 participants, 134 (98.5%) completed self-testing; two had invalid results. Comparing coordinator-performed TV rapid test adjudicated with NAAT, the sensitivity and specificity of self-administered test was 96.0% and 100%, respectively. The wet mount had a sensitivity of 52.0% and specificity of 100%. TV detection increased from 9.6% with wet mount to 18.4% with the TV rapid test. Most women (82.0%) stated self-testing was "not at all hard" (versus 66.2% before testing, p < 0.001). Clinicians indicated the TV rapid test affected their clinical management in 48.5% of cases, including 82.6% of positive cases and 41.6% of negative cases.ED patients were able to reliably collect, perform, and interpret their own POC TV test using tablet instructions. Both participants and providers reported high levels of acceptability of POC TV testing, which nearly doubled rates of TV detection.

Overcoming Challenges with the Adoption of Point-of-Care Testing: From Technology Push and Clinical Needs to Value Propositions

Major technical challenges often prevent developers from producing new point-of-care technologies that deliver the required clinical performance in the intended settings of use. But even when devices meet clinical requirements, they can fail to be adopted and successfully implemented. Adoption barriers occur when decision makers do not understand the "value proposition" of new technologies. Current discussions of value in the context of point-of-care testing focus predominantly on the intended use and performance of the device from the manufacturer's point-of-view. However, the perspective of potential adopters in determining whether new devices provide value is also important, as is the opinion of all stakeholders who will be impacted. Incorporating value concepts into decisions made across the full development-to-adoption continuum can increase the likelihood that point-of-care testing will have the desired impact on health care delivery and patient outcomes. This article discusses how various approaches to technology development impact adoption and compares the characteristics of these approaches to emerging value concepts. It also provides an overview of value initiatives and tools that are being developed to support the evaluation of value propositions. These are presented for a range of technology adoption decision contexts, with particular applicability to point-of-care testing. Expanding the focus of research to address gaps in both the creation and evaluation of value propositions is imperative in order for value concepts to positively influence the adoption of point-of-care testing.

Call to action for health systems integration of point-of-care testing to mitigate the transmission and burden of sexually transmitted infections

Objectives

In 2016, WHO estimated 376 million new cases of the four main curable STIs: gonorrhoea, chlamydia, trichomoniasis and syphilis. Further, an estimated 290 million women are infected with human papillomavirus. STIs may lead to severe reproductive health sequelae. Low-income and middle-income countries carry the highest global burden of STIs. A large proportion of urogenital and the vast majority of extragenital non-viral STI cases are asymptomatic. Screening key populations and early and accurate diagnosis are important to provide correct treatment and to control the spread of STIs. This article paints a picture of the state of technology of STI point-of-care testing (POCT) and its implications for health system integration.

Methods

The material for the STI POCT landscape was gathered from publicly available information, published and unpublished reports and prospectuses, and interviews with developers and manufacturers.

Results

The development of STI POCT is moving rapidly, and there are much more tests in the pipeline than in 2014, when the first STI POCT landscape analysis was published on the website of WHO. Several of the available tests need to be evaluated independently both in the laboratory and, of particular importance, in different points of care.

Conclusion

This article reiterates the importance of accurate, rapid and affordable POCT to reach universal health coverage. While highlighting the rapid technical advances in this area, we argue that insufficient attention is being paid to health systems capacity and conditions to ensure the swift and rapid integration of current and future STI POCT. Unless the complexity of health systems, including context, institutions, adoption systems and problem perception, are recognised and mapped, simplistic approaches to policy design and programme implementation will result in poor realisation of intended outcomes and impact.

Retrospective Chart Analysis of Child and Adolescent Trichomonas vaginalis Infection in Houston, Texas

BACKGROUND

Trichomonas vaginalis infection causes significant morbidity in the United States. Despite its high national disease burden, the epidemiologic characteristics of child and adolescent cases are not well understood. In this study, we aimed to describe the socioeconomic, transmission risk factors, clinical manifestations, and geospatial variables associated with cases of T vaginalis infection in the Houston, Texas, metropolitan area.

METHODS

We performed a retrospective chart abstraction of all T vaginalis cases at 2 large pediatric hospitals in Houston between 2008 and 2016.

RESULTS

We identified 87 patients (mean age, 16 years; range, 4-18 years); 30% of them were asymptomatic, and 39% were coinfected with another sexually transmitted infection(s). Almost all T vaginalis infections in sexually assaulted patients were diagnosed incidentally. Geospatial analysis identified clustering of cases in areas of high poverty and in minority populations.

CONCLUSIONS

Our findings indicate that children and adolescents are at risk for T vaginalis infection; however, their risk factors might differ from those in adults. In addition, our geospatial analysis revealed the need for dedicated resources in neighborhoods associated with health disparities to prevent future incident cases.

Rapid electrostatic DNA enrichment for sensitive detection of Trichomonas vaginalis in clinical urinary samples

Estimated to be the most common non-viral sexually transmitted infection globally, Trichomonas vaginalis (TV) can lead to pelvic inflammatory disease, pregnancy complications, and increased risk of acquiring and transmitting HIV. Once diagnosed, TV infection can be treated with oral antibiotics; however, infected individuals are often asymptomatic and do not seek treatment. The WHO and others have identified a need for point-of-care tests to expand access to TV testing and screening; ideal test characteristics include high sensitivity and specificity and the ability to use urine as a sample type, rather than invasively collected swab samples. Here, we report on a proof-of-concept prototype for rapid, electrostatic enrichment of DNA from urine samples and demonstrate the use of large volumes of urine to increase sensitivity of downstream nucleic acid amplification testing. We developed an internally controlled thermophilic helicase-dependent amplification (tHDA) assay with lateral flow immunoassay readout and demonstrate that this tHDA assay can be performed directly on our DNA capture filter. We validated our method using clinical urine samples with qPCR-quantified TV loads. Using 62 clinical urine samples and a simple sample processing device, our tHDA assay displayed 96.6% sensitivity and 100% specificity. Our analytical limit of detection was found to be approximately 7 genomic equivalents of TV DNA per mL of sample when 1 mL of sample was tested, comparable to existing isothermal tests for TV. Using large-volume simulated samples (40 mL of buffered urine with spiked-in TV DNA), we also demonstrated that sensitivity could be improved 28-fold to 0.25 genomic equivalents of TV DNA per mL, with a sample processing time of only 2 minutes.

Emerging Designs of Electronic Devices in Biomedicine

A long-standing goal of nanoelectronics is the development of integrated systems to be used in medicine as sensor, therapeutic, or theranostic devices. In this review, we examine the phenomena of transport and the interaction between electro-active charges and the material at the nanoscale. We then demonstrate how these mechanisms can be exploited to design and fabricate devices for applications in biomedicine and bioengineering. Specifically, we present and discuss electrochemical devices based on the interaction between ions and conductive polymers, such as organic electrochemical transistors (OFETs), electrolyte gated field-effect transistors (FETs), fin field-effect transistor (FinFETs), tunnelling field-effect transistors (TFETs), electrochemical lab-on-chips (LOCs). For these systems, we comment on their use in medicine.

School suspension predicts trichomoniasis five years later in a matched sample

BACKGROUND

Young adults who were suspended from school during adolescence are more likely than matched non-suspended youth to be arrested, on probation, or not graduate from high school, which are STI risk factors. This study evaluates whether suspension is a marker for STI risk among young adults who avoid subsequent negative effects.

METHODS

This study evaluated whether suspension predicts a positive test for chlamydia, gonorrhea, or trichomoniasis in a urine sample using matched sampling in the National Longitudinal Study of Adolescent and Adult Health (Add Health), and evaluated potential mediators between suspension and STI status using causal mediation analysis. We used Mahalanobis and exact matched sampling within propensity score calipers to compare 381 youth suspended for the first time in a 1-year period with 980 non-suspended youth. The suspended and non-suspended youth were similar on 67 pre-suspension variables. We evaluated STI outcomes 5 years after suspension.

RESULTS

Before matching, suspended youth were more likely to test positive for trichomoniasis and gonorrhea, but not chlamydia, than non-suspended youth. Suspended youth were more likely to test positive for trichomoniasis 5 years after suspension than matched non-suspended youth (OR = 2.87 (1.40, 5.99)). Below-median household income before suspension explained 9% of the suspension-trichomoniasis association (p = 0.02), but criminal justice involvement and educational attainment were not statistically significantly mediators.

CONCLUSIONS

School suspension is a marker for STI risk. Punishing adolescents for initial deviance may cause them to associate with riskier sexual networks even if they graduate high school and avoid criminal justice system involvement. Suspension may compound disadvantages for youth from below-median-income families, who have fewer resources for recovering from setbacks.

Loop mediated isothermal amplification assay for detection of Trichomonas vaginalis in vaginal swabs among symptomatic women from North India

Trichomonas vaginalis is one of the most common curable sexually transmitted pathogens infecting both men and women worldwide. Unlike traditional methods such as microscopy and culture, nucleic acid amplification tests rapidly detect this agent, assisting in treatment. Conventional polymerase chain reaction (PCR), the loop-mediated isothermal amplification (LAMP), and the Xpert TV assay were evaluated using 28 microscopy positive T. vaginalis samples and 125 microscopy negative samples from symptomatic females of reproductive age. The sensitivity of all tests was 100% and the specificity was 100%, 100%, and 99·2% for PCR, Xpert TV, and LAMP, respectively. The inter-rater reliability was excellent for PCR: Xpert TV (kappa-coefficient = 1) and good for LAMP assay: Xpert TV/PCR (kappa-coefficient = 0·98) and conventional PCR: LAMP (kappa-coefficient = 0·98). The study highlights the importance of PCR for screening T. vaginalis in women, particularly in laboratories where the Xpert-TV assay is not available or not affordable. The LAMP assay showed a lower positive predictive value which merits further evaluation. SIGNIFICANCE AND IMPACT OF THE STUDY: Trichomonas vaginalis is a common sexually transmitted pathogen associated with considerable morbidity and risk of complications. Due to the limitations of traditional diagnostic modalities, three molecular assays were compared: conventional polymerase chain reaction (PCR), Xpert TV assay, and loop mediated isothermal amplification (LAMP) assay for detecting T. vaginalis in symptomatic females. All tests had a sensitivity of 100% and the inter-rater reliability was excellent for PCR: Xpert TV, and good for LAMP assay: Xpert TV/PCR. The translational impact of this study lies in the possible use of conventional PCR and LAMP in laboratories where the Xpert TV assay is not available or not affordable.

The Use of Motion Analysis as Particle Biomarkers in Lensless Optofluidic Projection Imaging for Point of Care Urine Analysis

Urine testing is an essential clinical diagnostic tool. The presence of urine sediments, typically analyzed through microscopic urinalysis or cell culture, can be indicative of many diseases, including bacterial, parasitic, and yeast infections, as well as more serious conditions like bladder cancer. Current urine analysis diagnostic methods are usually centralized and limited by high cost, inconvenience, and poor sensitivity. Here, we developed a lensless projection imaging optofluidic platform with motion-based particle analysis to rapidly detect urinary constituents without the need for concentration or amplification through culture. A removable microfluidics channel ensures that urine samples do not cross contaminate and the lens-free projection video is captured and processed by a low-cost integrated microcomputer. A motion tracking and analysis algorithm is developed to identify and track moving objects in the flow. Their motion characteristics are used as biomarkers to detect different urine species in near real-time. The results show that this technology is capable of detection of red and white blood cells, Trichomonas vaginalis, crystals, casts, yeast and bacteria. This cost-effective device has the potential to be implemented for timely, point-of-care detection of a wide range of disorders in hospitals, clinics, long-term care homes, and in resource-limited regions.

Sexually Transmitted Infections: Prevention, Diagnosis, and Treatment in Primary Care

Most adolescents are cared for by general pediatricians, family practitioners, and mid-level providers. As a result, primary care practitioners need to be prepared to answer questions from adolescent patients and their parents about sexually transmitted infections (STIs), to practice good preventive medicine through screening and vaccination, and to provide treatment of STIs when needed. Although the topic of STIs is broad, there are common scenarios that arise in adolescent care. This review takes a pragmatic look at some of the most routine topics in adolescent health care regarding STIs, including the provision of confidential care, discussions with adolescent patients and their parents about human papillomavirus vaccination, the diagnosis and treatment of urethritis and cervicitis, and STI screening recommendations. [Pediatr Ann. 2019;48(9):e370-e375.].

Diagnosing sexually transmitted infections in resource-constrained settings: challenges and ways forward

INTRODUCTION

Sexually transmitted infections (STIs) remain prevalent and are increasing in several populations. Appropriate STI diagnosis is crucial to prevent the transmission and sequelae of untreated infection. We reviewed the diagnostic accuracy of syndromic case management and existing point-of-care tests (POCTs), including those in the pipeline, to diagnose STIs in resource-constrained settings.

METHODS

We prioritized updating the systematic review and meta-analysis of the diagnostic accuracy of vaginal discharge from 2001 to 2015 to include studies until 2018. We calculated the absolute effects of different vaginal flowcharts and the diagnostic performance of POCTs on important outcomes. We searched the peer-reviewed literature for previously conducted systematic reviews and articles from 1990 to 2018 on the diagnostic accuracy of syndromic management of vaginal and urethral discharge, genital ulcer and anorectal infections. We conducted literature reviews from 2000 to 2018 on the existing POCTs and those in the pipeline.

RESULTS AND DISCUSSIONS

The diagnostic accuracy of urethral discharge and genital ulcer disease syndromes is relatively adequate. Asymptomatic Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections limit the use of vaginal discharge and anorectal syndromes. The pooled diagnostic accuracy of vaginal syndromic case management for CT/NG is low, resulting in high numbers of overtreatment and missed treatment. The absolute effect of POCTs was reduced overtreatment and missed treatment. Findings of the reviews on syndromic case management underscored the need for low-cost and accurate POCTs for the identification, first, of CT/NG, and, second, of Mycoplasma genitalium (MG) and Trichomonas vaginalis (TV) and NG and MG resistance/susceptibility testing. Near-patient POCT molecular assays for CT/NG/TV are commercially available. The prices of these POCTs remain the barrier for uptake in resource-constrained settings. This is driving the development of lower cost solutions.

CONCLUSIONS

The WHO syndromic case management guidelines should be updated to raise the quality of STI management through the integration of laboratory tests. STI screening strategies are needed to address asymptomatic STIs. POCTs that are accurate, rapid, simple and affordable are urgently needed in resource-constrained settings to support the uptake of aetiological diagnosis and treatment.

Self-collection of samples as an additional approach to deliver testing services for sexually transmitted infections: a systematic review and meta-analysis

BACKGROUND

Self-collection of samples for diagnostic testing offers the advantages of patient autonomy, confidentiality and convenience. Despite data showing their feasibility and accuracy, there is a need to better understand how to implement such interventions for sexually transmitted infections (STIs). To support WHO guidelines on self-care interventions, we conducted a systematic review to investigate whether self-collection of samples should be made available as an additional approach to deliver STI testing services.

METHODS

Peer-reviewed studies were included if they compared individuals who self-collected samples for chlamydia, gonorrhoea, syphilis and/or trichomonas testing to individuals who had samples collected by clinicians on the following outcomes: uptake/frequency of STI testing, social harms/adverse events, positive yield (case finding), linkage to clinical assessment/treatment and reported sexual risk behaviour. We searched PubMed, CINAHL, LILACS and EMBASE for articles published through July 2018. Risk of bias was assessed using the Cochrane tool for randomised controlled trials (RCTs) and the Evidence Project tool for non-RCTs. Meta-analysis was conducted using random effects models to generate pooled estimates of relative risk (RR).

RESULTS

Eleven studies, including five RCTs and six observational studies with a total of 202 745 participants, met inclusion criteria. Studies were conducted in Australia, Denmark and the USA. Meta-analysis found that programmes offering self-collection of samples increased overall uptake of STI testing services (RR: 2.941, 95% CI 1.188 to 7.281) and case finding (RR: 2.166, 95% CI 1.043 to 4.498). No studies reported measuring STI testing frequency, social harms/adverse events, linkage to care or sexual risk behaviour.

DISCUSSION

While greater diversity in study designs, outcomes and settings would strengthen the evidence base, findings from this review suggest that self-collection of STI samples could be an effective additional strategy to increase STI testing uptake.

PROSPERO REGISTRATION NUMBER

PROSPERO CRD42018114866.

WHO laboratory validation of Xpert® CT/NG and Xpert® TV on the GeneXpert system verifies high performances

Effective tests for diagnosis of sexually transmitted infections (STIs), used point of care to inform treatment and management decisions, are urgently needed. We evaluated the analytical sensitivity and specificity of the Xpert^® CT/NG and Xpert^® TV tests, examining 339 samples spiked with phenotypically and/or genetically diverse strains of Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis, and other related species that may cross-react. The APTIMA Combo 2 test and APTIMA TV test were used as reference tests. The analytical sensitivity for all three agents in the Xpert^® CT/NG and Xpert^® TV tests was ≤10² genome equivalents/reaction. The analytical specificity of both tests was high. False-positive results were identified in the Xpert^® TV test when challenging with high concentrations of Trichomonas tenax, Trichomonas gallinae, Trichomonas stableri, and Trichomonas aotus. However, the clinical relevance of these cross-reactions can likely be neglected, because these species have not been identified in urogenital samples from humans. In conclusion, the analytical sensitivity and specificity of the user-friendly Xpert^® CT/NG and Xpert^® TV tests on the GeneXpert system were high. The results support the use of specimens from also extra-genital sites, for example, pharynx and rectum. However, appropriate clinical validations are additionally required.

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.

Beyond syndromic management: Opportunities for diagnosis-based treatment of sexually transmitted infections in low- and middle-income countries

Introduction

In light of the limited impact the syndromic management approach has had on the global sexually transmitted infection (STI) epidemic, we assessed a care model comprising point-of-care (POC) STI testing, immediate treatment, and expedited partner therapy (EPT) among a cohort of young women at high HIV risk in South Africa.

Methods and findings

HIV negative women presenting for STI care underwent POC testing for Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Trichomonas vaginalis (TV), and swabs were sent for NG culture and susceptibility testing. Results were available within 2 hours and women with STIs were immediately treated and offered EPT packs, including medication, condoms, and information for sexual partners. An EPT questionnaire was administered after one week, and women retested for STIs after 6 and 12 weeks. 267 women, median age 23 (IQR 21–26), were recruited and 88.4% (236/267) reported genital symptoms. STI prevalence was CT 18.4% (95%CI 13.7–23.0), NG 5.2% (95%CI 2.6–7.9) and TV 3.0% (95%CI 1.0–5.0). After 12 weeks, all but one NG and two CT infections were cleared. No cephalosporin-resistant NG was detected. Of 63/267 women (23.6%) diagnosed with STIs, 98.4% (62/63) were offered and 87.1% (54/62) accepted EPT. At one week 88.9% (48/54) stated that their partner had taken the medication. No allergic reactions or social harms were reported. Of 51 women completing 6-week follow up, detection rates were lower amongst women receiving EPT (2.2%, 1/46) compared to those who did not (40.0%, 2/5), p = 0.023. During focus group discussions women supported the care model, because they received a rapid, specific diagnosis, and could facilitate their partners’ treatment.

Conclusions

POC STI testing and EPT were acceptable to young South African women and their partners, and could play an important role in reducing STI reinfection rates and HIV risk. Larger studies should evaluate the feasibility and cost-effectiveness of implementing this strategy at population level.

Sexually transmitted infections: challenges ahead

WHO estimated that nearly 1 million people become infected every day with any of four curable sexually transmitted infections (STIs): chlamydia, gonorrhoea, syphilis, and trichomoniasis. Despite their high global incidence, STIs remain a neglected area of research. In this Commission, we have prioritised five areas that represent particular challenges in STI treatment and control. Chlamydia remains the most commonly diagnosed bacterial STI in high-income countries despite widespread testing recommendations, sensitive and specific non-invasive testing techniques, and cheap effective therapy. We discuss the challenges for chlamydia control and evidence to support a shift from the current focus on infection-based screening to improved management of diagnosed cases and of chlamydial morbidity, such as pelvic inflammatory disease. The emergence and spread of antimicrobial resistance in Neisseria gonorrhoeae is globally recognised. We review current and potential future control and treatment strategies, with a focus on novel antimicrobials. Bacterial vaginosis is the most common vaginal disorder in women, but current treatments are associated with frequent recurrence. Recurrence after treatment might relate to evidence that suggests sexual transmission is integral to the pathogenesis of bacterial vaginosis, which has substantial implications for the development of effective management approaches. STIs disproportionately affect low-income and middle-income countries. We review strategies for case management, focusing on point-of-care tests that hold considerable potential for improving STI control. Lastly, STIs in men who have sex with men have increased since the late 1990s. We discuss the contribution of new biomedical HIV prevention strategies and risk compensation. Overall, this Commission aims to enhance the understanding of some of the key challenges facing the field of STIs, and outlines new approaches to improve the clinical management of STIs and public health.