Modelling-based evaluation of the costs, benefits and cost-effectiveness of multipathogen point-of-care tests for sexually transmitted infections in symptomatic genitourinary medicine clinic attendees

Point-of-care diagnostics for sexually transmitted infections among migrants in Greece

SETTING

Sexually transmitted infections (STIs) can impact individuals of any demographic. The most common pathogens causing STIs are Chlamydia trachomatis, Neisseria gonorrhea and Trichomonas vaginalis; these can be treated with specific antibiotics.

OBJECTIVE

To compare the GeneXpert CT/NG test-and-treat algorithm to the syndromic approach algorithm and their impact on antibiotic prescription for gonorrhoea and chlamydia STIs.

DESIGN

A retrospective observational study on women aged ≥18 years who accessed the Médecins Sans Frontières Day Care Centre in Athens with complaints related to urogenital infections between January 2021 and March 2022. Women with abnormal vaginal discharge, excluding clinically diagnosed candidiasis, were eligible for Xpert CT/NG testing.

RESULTS

Of the 450 women who accessed care, 84 were eligible for Xpert CT/NG testing, and only one was positive for chlamydia, therefore resulting in saving 81 doses of ceftriaxone and azithromycin, and 19 doses of metronidazole. The cost of Xpert CT/NG testing, including treatment was €4,606.37, while full antibiotic treatment would have costed €536.76.

CONCLUSION

The overall cost of the Xpert CT/NG test-and-treat algorithm was higher than the syndromic approach. However, quality of care should be weighed against the potential benefits of testing and syndromic treatment to determine the best option for each patient; we therefore advocate for decreasing the costs.

On-site testing and treatment of sexually transmitted infections among female sex workers using molecular point-of-care testing integrated into harm reduction services in Madrid, Spain

INTRODUCTION

This study aimed to evaluate the feasibility of molecular point-of-care testing for STIs, the prevalence of STIs and associated factors, and testing and treatment uptake among street-based female sex workers (FSWs) attending a mobile harm reduction unit in Madrid, Spain.

METHODS

This was a prospective, longitudinal study. From August 15th to December 6th, 2022, participants were screened for Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis using molecular testing (Xpert) on self-collected urine samples at a mobile harm reduction unit. Additionally, rapid tests were used to screen participants for HIV, hepatitis C virus (HCV), and syphilis. On-site same-day results and treatment for those infected were offered.

RESULTS

Among 77 FSWs included the median age was 40 (range, 33-48), 64 % were homeless, and 84 % reported drug use in the past six months. Four participants self-reported having HIV, of whom all were on antiretroviral therapy, and 14 (18 %) had HCV antibodies, including three with current infection. The prevalence of at least one STI was 66 %. When categorized by type of STI, the prevalences were as follows: 15 % for CT, 15 % for NG, 51 % for TV, and 21 % for syphilis. Notably, the prevalence of STIs was higher among FSW with recent drug use, with no cases of CT or NG detected among FSWs who did not recently use drugs. In adjusted analysis, drug use was associated an increased odds of having an STI (adjusted odds ratio, 10.47; 95 % CI: 1.67-65.42). All participants consented to screening, and all but one received on-site result-based linkage to treatment.

CONCLUSIONS

This study demonstrates the feasibility, high STI prevalence, and high linkage to testing and treatment following point-of-care molecular testing among street-based FSWs who have recently used drugs in Madrid, Spain.

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.

Impact of rapid near-patient STI testing on service delivery outcomes in an integrated sexual health service in the United Kingdom: a controlled interrupted time series study

OBJECTIVES

To evaluate the impact of a new clinic-based rapid sexually transmitted infection testing, diagnosis and treatment service on healthcare delivery and resource needs in an integrated sexual health service.

DESIGN

Controlled interrupted time series study.

SETTING

Two integrated sexual health services (SHS) in UK: Unity Sexual Health in Bristol, UK (intervention site) and Croydon Sexual Health in London (control site).

PARTICIPANTS

Electronic patient records for all 58 418 attendances during the period 1 year before and 1 year after the intervention.

INTERVENTION

Introduction of an in-clinic rapid testing system for gonorrhoea and chlamydia in combination with revised treatment pathways.

OUTCOME MEASURES

Time-to-test notification, staff capacity, cost per episode of care and overall service costs. We also assessed rates of gonorrhoea culture swabs, follow-up attendances and examinations.

RESULTS

Time-to-notification and the rate of gonorrhoea swabs significantly decreased following implementation of the new system. There was no evidence of change in follow-up visits or examination rates for patients seen in clinic related to the new system. Staff capacity in clinics appeared to be maintained across the study period. Overall, the number of episodes per week was unchanged in the intervention site, and the mean cost per episode decreased by 7.5% (95% CI 5.7% to 9.3%).

CONCLUSIONS

The clear improvement in time-to-notification, while maintaining activity at a lower overall cost, suggests that the implementation of clinic-based testing had the intended impact, which bolsters the case for more widespread rollout in sexual health services.

Utilization of point-of-care tests among general practitioners, a cross-sectional study

Background

Point-of-care testing (POCT) has numerous potential benefits to improve health care service, especially in resource-limited settings. We aim to identify which POC-tests (POCTs) of laboratory parameters are known, employed, and rated as useful by general practitioners (GPs).

Methods

A questionnaire with 27 POCTs was posted to a random selection of GPs (n = 451) in Saxony, Germany.

Results

A total of 208 GPs replied (response rate 46.1%). Out of 27 POCTs, each GP knew an average of 20.3 as laboratory parameters and 9.2 as POCTs. Urine test strips (99.0%), blood glucose test (98.1%), and Troponin I/T (86.4%) were the best-known, followed by INR/Quick (82.5%), Microalbumin (79.1%), and D-dimer (78.6%) POCTs. Yet, solely 0 to 13 POC tests were actually used (mean value 4.6). Urine test strips were employed most frequently (97.6%), followed by blood glucose test (94.7%), Troponin I/T (57.8%), Microalbumin (57.3%), and INR/Quick POCTs (41.7%). Heart fatty binding protein (H-FABP), Syphilis, Coeliac disease, and Malaria appeared as the least frequently used POCTs. The majority of the GPs declared 14 of the 27 POCTs to be useful.

Discussion/conclusion

The most recurrently employed POCTs are those for diagnosing or monitoring diabetes mellitus, ensued by POCTs addressing acute cardiovascular diseases (Troponin I/T, D-dimer) or monitoring the therapy of infectious diseases or the anticoagulant therapy. POCTs most often rated as useful by GPs are also widely known and frequently used. Nonetheless, the majority of GPs rate only a very limited number of POCTs as useful. Frequent concerns might be low economic benefit, over-reliance, and test accuracy coming along with the complex implementation of the tests requiring technical skills, accurate storage, and the correct interpretation of test results.

Trial registration

In accordance with the (Model) Professional Code for Physicians in Germany, neither human body materials nor data that can be assigned to a specific human being are used in our study. A declaration of no objection from the Ethics Committee of the Martin-Luther University Halle-Wittenberg (Medical Faculty) confirms no professional or ethical concerns due to completely anonymized data collection and analysis. Our study was therefore not registered in a corresponding registry.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12875-022-01643-9.

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.

Assessing the clinical impact and resource use of a 30-minute chlamydia and gonorrhoea point-of-care test at three sexual health services

Objectives

To assess clinical metrics and resource use of a 30-minute point-of-care test (POCT) for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) compared to laboratory-based testing.

Methods

Three English sexual health services (SHSs) were recruited as part of a study. Existing processes for CT/NG testing and treatment were assessed, and adaptions to incorporate the CT/NG POCT were developed during semi-structured interviews. Staff time and consumables data were collected by clinic staff prior to and following introduction of the POCT.

Results

SHSs selected patient groups for whom the CT/NG POCT would be used. Testing and treatment process data were collected for 225 patients (n = 118 POC; n = 107 standard). The percentage of patients receiving unnecessary CT treatment was 5% (5/95) and 13% (12/93) for POC and standard care respectively. The average CT/NG pathway cost varied and was on average £61.55 for POC and £50.88 for standard care. For the two SHSs where the POCT was used during a patient's visit, for standard and POC respectively, the average time to CT treatment was 10.0 and 0.0 days and to NG treatment, 0.3 and 0.0 days.

Conclusion

Use of a 30-minute POCT at three SHSs yielded clinical benefits by reducing time to treatment and unnecessary CT treatment.

What can be learnt from a qualitative evaluation of implementing a rapid sexual health testing, diagnosis and treatment service?

OBJECTIVES

To investigate experiences of implementing a new rapid sexual health testing, diagnosis and treatment service.

DESIGN

A theory-based qualitative evaluation with a focused ethnographic approach using non-participant observations and interviews with patient and clinic staff. Normalisation process theory was used to structure interview questions and thematic analysis.

SETTING

A sexual health centre in Bristol, UK.

PARTICIPANTS

26 patients and 21 staff involved in the rapid sexually transmitted infection (STI) service were interviewed. Purposive sampling was aimed for a range of views and experiences and sociodemographics and STI results for patients, job grades and roles for staff. 40 hours of observations were conducted.

RESULTS

Implementation of the new service required co-ordinated changes in practice across multiple staff teams. Patients also needed to make changes to how they accessed the service. Multiple small 'pilots' of process changes were necessary to find workable options. For example, the service was introduced in phases beginning with male patients. This responsive operating mode created challenges for delivering comprehensive training and communication in advance to all staff. However, staff worked together to adjust and improve the new service, and morale was buoyed through observing positive impacts on patient care. Patients valued faster results and avoiding unnecessary treatment. Patients reported that they were willing to drop-off self-samples and return for a follow-up appointment, enabling infection-specific treatment in accordance with test results, thus improving antimicrobial stewardship.

CONCLUSIONS

The new service was acceptable to staff and patients. Implementation of service changes to improve access and delivery of care in the context of stretched resources can pose challenges for staff at all levels. Early evaluation of pilots of process changes played an important role in the success of the service by rapidly feeding back issues for adjustment. Visibility to staff of positive impacts on patient care is important in maintaining morale.

A profile of the binx health io® molecular point-of-care test for chlamydia and gonorrhea in women and men

Introduction: Point-of-care (POC) tests for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are urgently needed to control the STI epidemic in order to offer patients an immediate diagnoses and accurate treatment before they leave a clinical encounter and thus reduce transmission and sequelae. Nucleic acid amplification tests (NAATs) have increased sensitivity and specificity, but very few POC assays can provide results of such tests within the usual time of the patient visit.Areas covered: This review describes the technology and performance characteristics of the binx health io® [Boston, MA] (binx io) CT/NG assay, a new rapid molecular POC assay. The assay is compared to other available molecular POC tests. We also describe the importance of time to results and assay performance for this POC assay.Expert opinion: The binx io CT/NG assay offers the ability to incorporate the use of POC tests to identify and immediately treat chlamydia and gonococcal infections into the clinical visit, which will provide improved outcomes for patients. Additional implementation studies are needed to optimize the adoption of this new test.

Prevalence and correlates of Mycoplasma genitalium infection among patients attending a sexually transmitted infection clinic in Guangdong, China: a cross-sectional study

Background

Mycoplasma genitalium (MG) causes urogenital tract infections and is associated with reproductive morbidity. Although MG has been reported across many regions and population groups, it is not yet routinely tested for in China. Our study contributes to current research by reporting the prevalence and correlates of MG infection in patients attending a sexually transmitted infection (STI) clinic in Guangdong from Jan 2017-May 2018.

Methods

Urethral (from 489 men) and endo-cervical (from 189 women) samples, blood samples, and patient histories (via questionnaires) were collected. Doctors clinically diagnosed anogenital warts (GW) during the examination (n = 678). The presence of MG was evaluated using an in-house via polymerase chain reaction protocol. We also tested all participants for herpes simplex virus-2 (HSV-2), Neisseria gonorrhoeae (NG), Chlamydia trachomatis (CT), syphilis and HIV. Univariate and multivariate logistic regression were used to evaluate factors associated with MG.

Results

MG was detected in 7.2% (49/678) of the patients (men, 7.4%; women, 6.9%). The MG positivity rate was 14.2% among symptomatic patients, and 5.6% for asymptomatic patients, respectively. Only 36.7% (18/49) Mg positive patients were symptomatic. Among the MG-infected patients, 10.2% were co-infected with CT, 6.1% with NG, 8.2% with HSV-2, 4.1% with syphilis and 22.4% with GW. Presentation with clinical symptoms was significantly associated with MG infection [OR = 2.52 (2.03–3.13)]. In our analysis, MG was not associated with other STIs.

Conclusions

MG is a relatively common infection among individuals attending an STI clinic in Guangdong Province. Routine testing of symptomatic patients may be necessary, and more epidemiological studies are needed to provide evidence for future testing guidelines.

The Estimated Lifetime Medical Cost of Chlamydia, Gonorrhea, and Trichomoniasis in the United States, 2018

BACKGROUND

The purpose of this study was to provide updated estimates of the average lifetime medical cost per infection for chlamydia, gonorrhea, and trichomoniasis.

METHODS

We adapted a published decision tree model that allowed for 7 possible outcomes of infection: (1) symptomatic infection, treated, no sequelae; (2) symptomatic infection, not treated, sequelae; (3) symptomatic infection, not treated, no sequelae; (4) asymptomatic infection, treated, sequelae; (5) asymptomatic infection, treated, no sequelae; (6) asymptomatic infection, not treated, sequelae; and (7) asymptomatic infection, not treated, no sequelae. The base case values and ranges we applied for the model inputs (i.e., the probability and cost assumptions) were based on published studies.

RESULTS

The estimated lifetime medical costs per infection for men and women, respectively, were $46 (95% credibility interval, $32-$62) and $262 ($127-$483) for chlamydia, $78 ($36-$145) and $254 ($96-$518) for gonorrhea, and $5 ($1-$14) and $36 ($17-$58) for trichomoniasis. Cost estimates for men were most sensitive to assumptions regarding the probability that the infection is symptomatic, the probability of treatment if asymptomatic, and the cost of treatment of infection. Cost estimates for chlamydia and gonorrhea in women were most sensitive to assumptions regarding the probability and cost of subsequent pelvic inflammatory disease.

CONCLUSIONS

These estimates of the lifetime medical cost per infection can inform updated estimates of the total annual cost of sexually transmitted infections in the United States, as well as analyses of the value and cost-effectiveness of sexually transmitted infection prevention interventions.

Antimicrobial resistance point-of-care testing for gonorrhoea treatment regimens: cost-effectiveness and impact on ceftriaxone use of five hypothetical strategies compared with standard care in England sexual health clinics

Background

Widespread ceftriaxone antimicrobial resistance (AMR) threatens Neisseria gonorrhoeae (NG) treatment, with few alternatives available. AMR point-of-care tests (AMR POCT) may enable alternative treatments, including abandoned regimens, sparing ceftriaxone use. We assessed cost-effectiveness of five hypothetical AMR POCT strategies: A-C included a second antibiotic alongside ceftriaxone; and D and E consisted of a single antibiotic alternative, compared with standard care (SC: ceftriaxone and azithromycin).

Aim

Assess costs and effectiveness of AMR POCT strategies that optimise NG treatment and reduce ceftriaxone use.

Methods

The five AMR POCT treatment strategies were compared using a decision tree model simulating 38,870 NG-diagnosed England sexual health clinic (SHC) attendees; A micro-costing approach, representing cost to the SHC (for 2015/16), was employed. Primary outcomes were: total costs; percentage of patients given optimal treatment (regimens curing NG, without AMR); percentage of patients given non-ceftriaxone optimal treatment; cost-effectiveness (cost per optimal treatment gained).

Results

All strategies cost more than SC. Strategy B (azithromycin and ciprofloxacin (azithromycin preferred); dual therapy) avoided most suboptimal treatments (n = 48) but cost most to implement (GBP 4,093,844 (EUR 5,474,656)). Strategy D (azithromycin AMR POCT; monotherapy) was most cost-effective for both cost per optimal treatments gained (GBP 414.67 (EUR 554.53)) and per ceftriaxone-sparing treatment (GBP 11.29 (EUR 15.09)) but with treatment failures (n = 34) and suboptimal treatments (n = 706).

Conclusions

AMR POCT may enable improved antibiotic stewardship, but require net health system investment. A small reduction in test cost would enable monotherapy AMR POCT strategies to be cost-saving.

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.

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.

Point-of-Care Testing in Microbiology: A Mechanism for Improving Patient Outcomes

BACKGROUND

Increasingly, demands for improved health and quality of life conflict with the realities of delivering healthcare in an environment of higher expenditures, adherence to test utilization, and patient-centered experience. Patient-centered care is commonly identified as a goal of healthcare delivery, and yet healthcare systems struggle with delivery of care to patients, often failing to identify the seriously ill and capitalize on the predictive qualities of diagnostic testing. Point-of-care (POC) testing provides access to rapid diagnosis and predictive value key to realizing patient outcomes. An evaluation of cost-effective models and the clinical impact of POC testing for clinical microbiology is needed.

CONTENT

Accurate and rapid diagnostics have the potential to affect healthcare decisions to a degree well out of proportion to their cost. Contemporary healthcare models increasingly view POC testing as a mechanism for efficient deployment of healthcare. POC testing can deliver rapid diagnosis in environments where testing results can be used to direct management during patient visits and in areas where centralized laboratory testing may limit access to care. Nucleic acid assays, designed for POC testing, can match, or exceed, the sensitivity of conventional laboratory-based testing, eliminating the need for confirmation testing. Here, the goals of POC testing for microbiology, applications, and technologies, as well as outcomes and value propositions, are discussed.

SUMMARY

The combination of rapid reporting, an increasing array of organisms capable of causing disease, actionable resulting, and improved patient outcomes is key in the evolution of POC testing in clinical microbiology.

Modelling patient flows and resource use within a sexual health clinic through discrete event simulation to inform service redesign

OBJECTIVES

Continuous improvement in the delivery of health services is increasingly being demanded in the UK at a time when budgets are being cut. Simulation is one approach used for understanding and assessing the likely impact of changes to the delivery of health services. However, little is known about the usefulness of simulation for analysing the delivery of sexual health services (SHSs). We propose a simulation method to model and evaluate patient flows and resource use within an SHS to inform service redesign.

METHODS

We developed a discrete event simulation (DES) model to identify the bottlenecks within the Unity SHS (Bristol, UK) and find possible routes for service improvement. Using the example of the introduction of an online service for sexually transmitted infection (STI) and HIV self-sampling for asymptomatic patients, the impact on patient waiting times was examined as the main outcome measure. The model included data such as patient arrival time, staff availability and duration of consultation, examination and treatment. We performed several sensitivity analyses to assess uncertainty in the model parameters.

RESULTS

We identified some bottlenecks under the current system, particularly in the consultation and treatment queues for male and female walk-in patients. Introducing the provision of STI and HIV self-sampling alongside existing services decreased the average waiting time (88 vs 128 min) for all patients and reduced the cost of staff time for managing each patient (£72.64 vs £88.74) compared with the current system without online-based self-sampling.

CONCLUSIONS

The provision of online-based STI and HIV self-sampling for asymptomatic patients could be beneficial in reducing patient waiting times and the model highlights the complexities of using this to cut costs. Attributing recognition for any improvement requires care, but DES modelling can provide valuable insights into the design of SHSs ensuing in quantifiable improvements. Extension of this method with the collection of additional data and the construction of more informed models seems worthwhile.

Evaluation of the Performance of a Point-of-Care Test for Chlamydia and Gonorrhea

IMPORTANCE

Rates of chlamydial and gonococcal infection continue to increase in the United States, as do the associated costs of untreated infections. Improved diagnostic technologies that support testing and treating in 1 clinical visit are critical to advancing efforts to control the rates of chlamydial and gonococcal infection.

OBJECTIVE

To evaluate the clinical performance of a point-of-care (POC) molecular diagnostic assay for the detection of chlamydia and gonorrhea.

DESIGN, SETTING, AND PARTICIPANTS

A noninterventional, cross-sectional clinical study was conducted from September 18, 2018, through March 13, 2019, at sexually transmitted infection (STI), HIV, family planning, and obstetrics and gynecology clinics where STI screening is routine, using a convenience sample and comparing commercially available assays with a new 30-minute POC assay. Patients included were those eligible for STI screening or diagnostic testing who had not taken antibiotics effective against chlamydia or gonorrhea within the previous 28 days. Four vaginal swab samples were collected from women and a first-catch urine sample was obtained from men.

MAIN OUTCOMES AND MEASURES

A composite infection status was used to classify participants as infected if 2 or more comparator results were positive, as not infected if 2 or more comparator samples were negative, and as unevaluable if 1 result was invalid and the other 2 results did not agree with each other.

RESULTS

Swab samples from 1523 women (median age, 27 years [interquartile range, 17-37 years]), 817 (53.6%) of whom presented with symptoms, and 922 men (median age, 29 years [interquartile range, 17-41 years]), 308 (33.4%) of whom were symptomatic, were tested. For chlamydia, sensitivity of the new POC assay was 96.1% (95% CI, 91.2%-98.3%) for women and 92.5% (95% CI, 86.4%-96.0%) for men. For gonorrhea, sensitivity estimates were 100.0% (95% CI, 92.1%-100.0%) for women and 97.3% (95% CI, 90.7%-99.3%) for men. For chlamydia, specificity of the new POC assay was 99.1% (95% CI, 98.4%-99.5%) for women and 99.3% (95% CI, 98.4%-99.7%) for men. For gonorrhea, specificity estimates were 99.9% (95% CI, 99.5%-100%) for women and 100% (95% CI, 95.5%-100%) for men. Non-laboratory-trained personnel performed 94.8% of all tests (2318 of 2445) during the study.

CONCLUSIONS AND RELEVANCE

This study suggests that self-obtained vaginal swab samples were associated with performance equivalent to laboratory-based molecular diagnostics, which can support use of this POC assay in many settings. The availability of an easy-to-use, rapid (30-minute) molecular test for accurate detection of chlamydia and gonorrhea has the power to facilitate testing and treatment in a single patient visit for these STIs.

Diagnosis of some genital-tract infections: part 2. Molecular tests and the new challenges

Promptly and accurately diagnosing genital-tract infections is key to instituting appropriate treatment and control of sexually transmitted infections (STIs). Ano-genital tract testing for STIs in the last two decades has not entirely moved away from insensitive methods but it is now at least dominated by highly sensitive molecular methods. These tests can be ordered through the internet for use at home, with self-taken specimens then returned, usually by post, to a clinic or laboratory for testing. The increasing ease of access of the public to this situation, together with increasing on-line health-seeking behaviour, has resulted in a gap between commercial and NHS management pathways for STIs. Crucially, patients who order multiplex test kits on-line for use at home, and other non-specialists, may not realize that it is worthwhile testing only for Neisseria gonorrhoeae, Chlamydia trachomatis, and possibly Trichomonas vaginalis, and Mycoplasma genitalium if the person is symptomatic or their current partner is infected. The detection and recommended treatment of micro-organisms which to some extent are part of the genital-tract microbiome, such as Mycoplasma hominis, Ureaplasma spp. or Gardnerella vaginalis, which do not cause symptoms in the majority of those infected, cannot be recommended. We argue that a shift from specialist-led to patient- and non-specialist-led STI management, in the presence of a clinical leadership vacuum, has increased the risk of inappropriate and unnecessary treatment which will drive macrolide, tetracycline and metronidazole antimicrobial resistance. However, in the past 5–6 years several groups have been able to show the value of on-line testing as a consequence of targeting the most important micro-organisms and using molecular tests to allow rapid and appropriately informed treatment. This should herald a brighter future, although there is still a need for leadership to expertly guide commercial and NHS sectors alike. In turn, this requires dedicated genito-urinary medicine commissioning to be maintained at a time when it appears to be most under threat.

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.

Simultaneous detection of Salmonella enterica, Escherichia coli and Listeria monocytogenes in food using a light scattering sensor

AIM

To investigate the use of a light scattering sensor, BActerial Rapid Detection using Optical scattering Technology (BARDOT) coupled with a multipathogen selective medium, Salmonella, Escherichia and Listeria (SEL), for concurrent detection of the three major foodborne pathogens in a single assay.

METHODS AND RESULTS

BARDOT was used to detect and distinguish the three major pathogens, Salmonella enterica, Shiga toxin-producing Escherichia coli (STEC) and Listeria monocytogenes from food based on colony scatter signature patterns on SEL agar (SELA). Multiple strains of three test pathogens were grown on SELA, and BARDOT was used to generate colony scatter image libraries for inclusive (SEL Library) and exclusive (non-SEL Library) bacterial group. These pathogens were further differentiated using the SEL scatter image library. Raw chicken and hotdog samples were artificially inoculated with pathogens (100 CFU per 25 g each), and enriched in SEL broth at 37°C for 18 h and colonies were grown on SELA for 11-22 h before screening with BARDOT. The BARDOT sensor successfully detected and differentiated Salmonella, STEC and Listeria on SELA with high classification accuracy 92-98%, 91-98% and 83-98% positive predictive values (PPV) respectively; whereas the nontarget strains showed only 0-13% PPV. BARDOT-identified colonies were further confirmed by multiplex PCR targeting inlB gene of L. monocytogenes, stx2 of STEC and sefA of S. enterica serovar Enteritidis.

CONCLUSIONS

The results show that BARDOT coupled with SELA can efficiently screen for the presence of three major pathogens simultaneously in a test sample within 29-40 h.

SIGNIFICANCE AND IMPACT OF THE STUDY

This innovative SELA-BARDOT detection platform can reduce turnaround time and economic burden on food industries by offering a label-free, noninvasive on-plate multipathogen screening technology for reducing microbial food safety and public health concerns.

Infections caused by Chlamydia trachomatis (including lymphogranuloma venereum) and Mycoplasma genitalium

Sexually transmitted infections caused by Chlamydia trachomatis, including lymphogranuloma venereum and Mycoplasma genitalium have increased in last decade. This epidemiological scenario presents new challenges in order to improve and strengthen our control and prevention strategies. The routine clinical diagnosis of urethritis and cervicitis must be combined with the active search for the causal agent in men with symptoms of dysuria or proctitis, and in women with pelvic inflammatory disease. We should also include sexually transmitted infections screening in asymptomatic patients with sexual risk behaviours or sexual contact with patients diagnosed with an sexually transmitted infection. The microbiological diagnosis must be based on molecular techniques capable of detecting Chlamydia trachomatis (discriminating between L genotypes associated with lymphogranuloma venereum and other genotypes) and Mycoplasma genitalium (ideally including the identification of macrolide-resistant strains). A faster and specific diagnosis will allow for a targeted treatment with a suitable antibiotic regimen. We also recommend including contact tracing of sexual partners and, occasionally, a cure test. Finally, sexually transmitted infection screening must be widely implemented in those population groups with a high prevalence of sexually transmitted infections.