Evaluation of a rapid point-of-care test for the detection of gonococcal infection among female sex workers in Benin

Neisseria gonorrhoeae Multivalent Maxibody with a Broad Spectrum of Strain Specificity and Sensitivity for Gonorrhea Diagnosis

Gonorrhea is one of the most common, but still hidden and insidious, sexually transmitted diseases caused by Neisseria gonorrhoeae (gonococci). However, the diagnosis and treatment of gonorrhea are hampered by antigenic variability among gonococci, the lack of acquired immunity, and antimicrobial resistance. Further, strains resistant to cephalosporins, including ceftriaxone, the last line of defense, represent a growing threat, which prompted us to develop gonococci-specific diagnostic antibodies with broad-spectrum binding to gonococci strains to generate gonorrhea-detecting reagents. This study reports the identification of gonococci antibodies via bio-panning on gonococci cells using scFv-phage libraries. Reformatting the lead scFv-phage Clones 1 and 4 to a multivalent scFv1-Fc-scFv4 maxibody increased the sensitivity by up to 20-fold compared to the single scFv-Fc (maxibody) alone. Moreover, the multivalent maxibody showed broader cross-reactivity with clinical isolates and the ceftriaxone antibiotic-resistant World Health Organization (WHO) reference strain L. In contrast, the selected antibodies in the scFv-phage, maxibody, and multivalent maxibody did not bind to N. sicca, N. meningitides, and N. lactamica, suggesting the clinical and pharmaceutical diagnostic value of these selected antibodies for gonorrheal infections. The present study illustrates the advantages and potential application of multivalent maxibodies to develop rapid and sensitive diagnostic reagents for infectious diseases and cancer.

Prevalence of Neisseria gonorrhoeae infection among women of reproductive age in sub-Saharan Africa: a systematic review and meta-analysis

OBJECTIVE

Neisseria gonorrhoeae infection is a global, major public health problem. It is the second leading bacterial sexually transmitted infection (STI) in sub-Saharan Africa and worldwide. As study findings on the topic are inconsistent, we conducted a systematic review and meta-analysis to determine the pooled prevalence of N. gonorrhoeae infection in sub-Saharan Africa among reproductive-aged women.

METHODS

Published studies were systematically retrieved from PubMed, Embase, CINHAL and Science Direct. Their quality was measured using the Joanna Briggs Institute critical appraisal checklist for studies reporting prevalence data, and the score of each included study had to meet at least 4.5 out of 9 indicators of quality.

RESULTS

The meta-analysis of 35 studies showed that the pooled prevalence of N. gonorrhoeae infection among reproductive-aged women in sub-Saharan Africa was 3.28% (95% confidence interval 2.61%, 3.94%).

CONCLUSION

The prevalence of N. gonorrhoeae infection was higher than that found in other studies carried out in the region. The results suggest that greater attention should be paid to the primary prevention of N. gonorrhoeae. We recommend the implementation of STI education for reproductive-aged women and the use of specific and rapid diagnostic testing for N. gonorrhoeae infection in STI clinics. N. gonorrhoeae screening and treatment should be integrated into in- and outpatient clinics to reduce infection among reproductive-aged women.

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.

Use of the mtrR Gene for Rapid Molecular Diagnosis of Neisseria gonorrhoeae and Identification of the Reduction of Susceptibility to Antibiotics in Endocervical Swabs

BACKGROUND

Neisseria gonorrhoeae is one of the main etiological agents of sexually transmitted diseases. The asymptomatic course of the infection and its resistance to antibiotics can lead to pelvic inflammatory disease and infertility.

OBJECTIVES

We developed a polymerase chain reaction (PCR) test using the methyltetrahydrofolate homocysteine methyltransferase reductase (mtrR) gene to identify N. gonorrhoeae and detect reduced susceptibility to antibiotics.

MATERIAL AND METHODS

We analysed 250 samples of endocervical exudate from infertile women with a negative diagnosis of N. gonorrhoeae. We designed NGmtr primers to detect N. gonorrhoeae and identify the antibiotic-resistant strain.

RESULTS

Of the 250 samples, 60 (24%) tested positive for N. gonorrhoeae using real-time PCR. Our study was validated using the HO primers and the Seeplex STD6 ACE System, with a 100% correlation. Furthermore, the NGmtr primers are specific for N. gonorrhoeae and not for other species. Additionally, the curves generated by real-time PCR differed between wild and variant strains (10.93%). The dissociation temperatures for the wild and variant strains were 86.5 and 89 °C, respectively.

CONCLUSIONS

The NGmtr primers enabled us to identify N. gonorrhoeae strains with or without reduction of susceptibility to antibiotics. Therefore, this work constitutes a tool that will facilitate the diagnosis of this infection for a low cost and improve patient quality of life.

A paperfluidic platform to detect Neisseria gonorrhoeae in clinical samples

Globally, the microbe Neisseria gonorrhoeae (NG) causes 106 million newly documented sexually transmitted infections each year. Once appropriately diagnosed, NG infections can be readily treated with antibiotics, but high-risk patients often do not return to the clinic for treatment if results are not provided at the point of care. A rapid, sensitive molecular diagnostic would help increase NG treatment and reduce the prevalence of this sexually transmitted disease. Here, we report on the design and development of a rapid, highly sensitive, paperfluidic device for point-of-care diagnosis of NG. The device integrates patient swab sample lysis, nucleic acid extraction, thermophilic helicase-dependent amplification (tHDA), an internal amplification control (NGIC), and visual lateral flow detection within an 80 min run time. Limits of NG detection for the NG/NGIC multiplex tHDA assay were determined within the device, and clinical performance was validated retroactively against qPCR-quantified patient samples in a proof-of-concept study. This paperfluidic diagnostic has a clinically relevant limit of detection of 500 NG cells per device with analytical sensitivity down to 10 NG cells per device. In triplicate testing of 40 total urethral and vaginal swab samples, the device had 95% overall sensitivity and 100% specificity, approaching current laboratory-based molecular NG diagnostics. This diagnostic platform could increase access to accurate NG diagnoses to those most in need.

Surface enhanced Raman spectroscopy of Chlamydia trachomatis and Neisseria gonorrhoeae for diagnostics, and extra-cellular metabolomics and biochemical monitoring

SERS spectra excited at 785 nm of the bacteria Chlamydia trahomatis (elementary bodies, EB) and Neisseria gonorrheoae, the causative pathogens for the two most common sexually transmitted diseases (STD), chlamydia and gonorrhea, respectively, are reported. Although both are Gram-negative bacteria, the SERS signatures of C. trachomatis and N. gonorrheoae are completely different. N. gonorrheoae SERS spectra are due to the starvation induced nucleotide metabolites adenine and guanine, and the surface associated co-enzyme nicotinamide adenine dinucleotide and are very similar on Au and Ag although the spectrum appears more rapidly on Ag. The C. trachomatis SERS spectrum is dominated by the vibrational features of cell surface proteins. While features attributable to specific residues and the amide backbone characterize the C. trachomatis spectrum on Ag, the corresponding SERS spectrum on Au substrates displays vibrational characteristics of aggregated proteins. The prospects for the development of a SERS based platform for rapid (<one hour), low-cost bacterial STD diagnostics are promising based on these initial studies. Furthermore, this biomedical application demonstrates the potential for SERS to be a sensitive real time probe of the dynamics of biochemical activity in the cell wall and extracellular regions of microorganisms.

Performance and operational characteristics of point-of-care tests for the diagnosis of urogenital gonococcal infections

BACKGROUND

In 2012, there was an estimated 78 million new cases of gonorrhoea globally. Untreated infection may lead to reproductive and neonatal morbidity and facilitate HIV transmission. Diagnosis and treatment are a priority for control and prevention, yet use of point-of-care tests (POCTs) for Neisseria gonorrhoeae (NG) is limited.

OBJECTIVES

To review the performance and operational characteristics of NG POCTs for diagnosis of urogenital gonorrhoea.

METHODS

We compiled and synthesised findings from two separate systematic reviews which included evaluations published until August 2015.

RESULTS

Six tests were included: five were immunochromatographic tests (ICTs) or optical immunoassay (OIAs) based on antigen detection; with 5-7 steps and results in 25-40 min, and one (GeneXpert CT/NG) was a 'near-patient test' based on nucleic acid amplification technique (NAAT); with three steps, electricity required, and results in 90 min. When compared with laboratory-based NAATs as the reference tests, sensitivities of ICT and OIA-based POCTs ranged from 12.5% to 70% when cervical/vaginal swabs were tested. Specificities ranged from 89% to 99.8%. The near-patient NAAT had sensitivities of >95% and specificities of >99.8% consistently across all specimen types (urine, cervical and vaginal swabs).

CONCLUSIONS

Based on a limited number of evaluations, antigen detection POCTs for NG lacked sufficient sensitivity to be used for screening. A near-patient NAAT has acceptable performance, only involved a few steps, but needs electricity, a temperature-controlled environment and has a 90 min run time. To achieve wider scale up of NG POCTs, we need strong evidence of cost-effectiveness, which should inform guidelines and ultimately increase test development, demand and reduce costs.

Genital Chlamydia trachomatis and Neisseria gonorrhoeae infections among women in sub-Saharan Africa: A structured review

Chlamydia trachomatis and Neisseria gonorrhoeae constitute major public health problems among women, but the burden of infection in sub-Saharan Africa is poorly documented. We conducted a structured review of the prevalence and incidence of genital, oral and anal C. trachomatis and N. gonorrhoeae infection in women in sub-Saharan Africa. We searched Medline, EMBASE and Web of Science over a 10-year period for studies on epidemiology of genital, oral and anal chlamydial infection and gonorrhoea in women in all countries of sub-Saharan Africa. We assessed geographic and demographic differences in prevalence and incidence of infection; weighted mean prevalence estimates were calculated with a random-effect model. A total of 102 study results were included, with data available for 24/49 of sub-Saharan countries. The weighted prevalence of chlamydial infection was lower among women in community-based studies (3.9%; 95% CI: 2.9-5.1%) than for women recruited at primary healthcare facilities (6.0%; 95% CI: 4.2-8.4%, p < 0.001); the same was observed for gonorrhoea (2.2%; 95% CI: 1.2-4.0% vs. 4.2%; 95% CI: 3.2-5.6%, p < 0.001). Prevalence of Chlamydia among sex workers was 5.5% (95% CI: 4.2-7.3%) and gonorrhoea 7.6% (95% CI: 5.4-11%). Seven studies reported on incidence which varied between 0.75-28 and 2.8-17 per 100 person-years-at-risk for chlamydial infection and gonorrhoea, respectively. Only two studies reported on anal infections and one on oral infection. This overview underscores the considerable incidence and prevalence of genital C. trachomatis and N. gonorrhoeae in women in different settings in sub-Saharan Africa. Better control strategies are warranted to reduce the burden of infection and to prevent long-term complications of these infections.

How Reliable Is Microscopy and Culture for the Diagnosis of Gonorrhea? An 11-Year Experience from INDIA

Positivity of microscopy and culture was greater (P < 0.0001) in men with urethral discharge syndrome (65.8%) than in women with vaginal/cervical discharge (0.5%), indicating that basic diagnostic tests may not be cost-effective for diagnosis of vaginal/cervical discharge syndrome. Microscopy when compared with culture showed sensitivity, specificity, positive predictive value and negative predictive value of 95.4%, 77.6%, 84.6%, and 95.3%, in men, whereas in women, it was 77.8%, 99.9%, 92.1%, and 99.9%, respectively.

Point-of-care cardiac troponin test accurately predicts heat stroke severity in rats

Heat stroke (HS) remains a significant public health concern. Despite the substantial threat posed by HS, there is still no field or clinical test of HS severity. We suggested previously that circulating cardiac troponin (cTnI) could serve as a robust biomarker of HS severity after heating. In the present study, we hypothesized that (cTnI) point-of-care test (ctPOC) could be used to predict severity and organ damage at the onset of HS. Conscious male Fischer 344 rats (n = 16) continuously monitored for heart rate (HR), blood pressure (BP), and core temperature (Tc) (radiotelemetry) were heated to maximum Tc (Tc,Max) of 41.9 ± 0.1°C and recovered undisturbed for 24 h at an ambient temperature of 20°C. Blood samples were taken at Tc,Max and 24 h after heat via submandibular bleed and analyzed on ctPOC test. POC cTnI band intensity was ranked using a simple four-point scale via two blinded observers and compared with cTnI levels measured by a clinical blood analyzer. Blood was also analyzed for biomarkers of systemic organ damage. HS severity, as previously defined using HR, BP, and recovery Tc profile during heat exposure, correlated strongly with cTnI (R(2) = 0.69) at Tc,Max. POC cTnI band intensity ranking accurately predicted cTnI levels (R(2) = 0.64) and HS severity (R(2) = 0.83). Five markers of systemic organ damage also correlated with ctPOC score (albumin, alanine aminotransferase, blood urea nitrogen, cholesterol, and total bilirubin; R(2) > 0.4). This suggests that cTnI POC tests can accurately determine HS severity and could serve as simple, portable, cost-effective HS field tests.

The performance of non-NAAT point-of-care (POC) tests and rapid NAAT tests for chlamydia and gonorrhoea infections. An assessment of currently available assays

OBJECTIVES

To identify point-of-care (POC) and rapid nucleic acid amplification techniques (NAATs) for the diagnosis of chlamydia and gonorrhoea and assess their utility.

METHODS

Literature search for available POC and rapid NAATs. The performance from the best-performing assays were applied hypothetically to patients in the clinic in which 100 consecutive patients with chlamydia and 100 with gonorrhoea were diagnosed in 1737 and 4575 patients respectively, with 44/100 and 54/100 treated at first attendance, respectively.

RESULTS

11 POC and 1 rapid NAAT were identified. Published performances for the best POC for chlamydia (CRT) were: sensitivity 41%-87%, specificity 89%-99.6%. Our data suggest that if this assay was used instead of our current NAAT, for every 100 patients diagnosed currently, 23-46 extra patients would be treated at first attendance; 10-35 would go undiagnosed with 7-191 false-positives. Best chlamydia rapid NAAT (GeneXpert): sensitivity 97.5%-98.7%, specificity 99.4%-99.9%. Anticipated performance for every 100 patients diagnosed currently: 0 extra patients treated at first attendance, 1-3 undiagnosed, 0-2 false-positives. Best POC for gonorrhoea (GC Check): sensitivity 54%-70%, specificity 97%-98%. Anticipated performance for every 100 patients diagnosed currently: 14-18 extra patients treated at first attendance, 28-32 undiagnosed, 92-137 false-positives. Best rapid NAAT for gonorrhoea (GeneXpert): sensitivity 96%-100%, specificity 99.9%-100%. Anticipated performance for every 100 patients diagnosed currently: 0 extra patients treated at first attendance, 0-4 undiagnosed, 0-5 false-positives. Rapid NAAT would reduce time to treatment by 4 days for initially untreated patients.

CONCLUSIONS

POC assays would need to be used in conjunction with a NAAT, increasing early treatment rates expense and false-positive results. The rapid NAAT could be used alone, with a reduction in average time-to-treat and a small reduction in sensitivity and specificity.

Diagnosis of Neisseria gonorrhoeae using molecular beacon

Neisseria gonorrhoeae is an important sexually transmitted diseases (STD) causing pathogen worldwide. Due to absence of an affordable diagnostic assay, routine screening of gonococcal infection becomes impossible in developing countries where infection rates are maximum. Treatment is given on the basis of symptoms alone which leads to spread of infection. Thus, development of a rapid, sensitive, specific, and PCR based visual diagnostic assay suitable for developing countries, required for better disease management, is aimed at in present study. Endocervical swabs were collected from patients visiting gynecology department of various hospitals in Delhi. In-house PCR based assay was developed and modified to visual assay using molecular beacon for end-point detection. It was evaluated against Roche AMPLICOR NG kit and rmp gene. Specificity of beacon was confirmed by competition experiments. Diagnostic test was 98.21% specific and 99.59% sensitive whereas negative and positive predicted value were 99.40% and 98.78%, respectively. We also observed that twice the concentration (2X) of premix was stable at 4°C for 4 months and dry swab samples gave concordant results with that of wet swabs. These features make the test best suitable for routine diagnosis of genital infections in developing countries.

A field evaluation of a new molecular-based point-of-care test for chlamydia and gonorrhoea in remote Aboriginal health services in Australia

Background Point-of-care (POC) tests could be important public health tools in settings with treatment delays and high rates of sexually transmissible infections (STIs). Use is limited due to suboptimal performance. The performance and ease-of-use of a new molecular-based POC test for simultaneous detection of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) was assessed, alongside two single-organism immunochromatographic tests (ICT).

METHODS

The evaluation occurred between May 2012 and March 2013 during community STI screens in two remote Aboriginal health services. Urine was tested with the GeneXpert(®)CT/NG and if sufficient volume, also with Diaquick CT and Gonorrhoea Card. The gold standard comparison was laboratory nucleic acid amplification testing (NAAT). Operational characteristics were also assessed.

RESULTS

Among 198 samples, GeneXpert CT sensitivity and specificity was 100% [95% confidence intervals (CI): 75.9-100] and 99.5% (95% CI: 96.5-100), and NG was 100% (95% CI: 96.5-100) and 100% (95% CI: 97.5-100), respectively. Among a sample subset, Diaquick CT (n=104) sensitivity and specificity was 27.3% (95% CI: 7.3-60.7) and 66.7% (95% CI: 12.5-98.2), and Gonorrhoea Card (n=29), was 66.7% (95% CI: 12.5-98.2) and 76.9% (95% CI: 56.0-90.2), respectively. GeneXpert required 1mL of urine, four steps, 1min specimen preparation and 90min to result. ICTs required 15mL of urine, eight steps, 18min preparation and 10-15min to result.

CONCLUSION

The accuracy and operational benefits of GeneXpert CT/NG make it very suitable in these settings where delays to treatment are encountered.

Point-of-care testing for chlamydia and gonorrhoea: implications for clinical practice

OBJECTIVES

Point-of-care (POC) testing for chlamydia (CT) and gonorrhoea (NG) offers a new approach to the diagnosis and management of these sexually transmitted infections (STIs) in remote Australian communities and other similar settings. Diagnosis of STIs in remote communities is typically symptom driven, and for those who are asymptomatic, treatment is generally delayed until specimens can be transported to the reference laboratory, results returned and the patient recalled. The objective of this study was to explore the clinical implications of using CT/NG POC tests in routine clinical care in remote settings.

METHODS

In-depth qualitative interviews were conducted with a purposively selected group of 18 key informants with a range of sexual health and laboratory expertise.

RESULTS

Participants highlighted the potential impact POC testing would have on different stages of the current STI management pathway in remote Aboriginal communities and how the pathway would change. They identified implications for offering a POC test, specimen collection, conducting the POC test, syndromic management of STIs, pelvic inflammatory disease diagnosis and management, interpretation and delivery of POC results, provision of treatment, contact tracing, management of client flow and wait time, and re-testing at 3 months after infection.

CONCLUSIONS

The introduction of POC testing to improve STI service delivery requires careful consideration of both its advantages and limitations. The findings of this study will inform protocols for the implementation of CT/NG POC testing, and also STI testing and management guidelines.

Point of care diagnostics for sexually transmitted infections: perspectives and advances

Accurate and inexpensive point-of-care (POC) tests are urgently needed to control sexually transmitted infection epidemics, so that patients can receive immediate diagnoses and treatment. Current POC assays for Chlamydia trachomatis and Neisseria gonorrhoeae perform inadequately and require better assays. Diagnostics for Trichomonas vaginalis rely on wet preparation, with some notable advances. Serological POC assays for syphilis can impact resource-poor settings, with many assays available, but only one available in the U.S. HIV POC diagnostics demonstrate the best performance, with excellent assays available. There is a rapid assay for HSV lesion detection; but no POC serological assays are available. Despite the inadequacy of POC assays for treatable bacterial infections, application of technological advances offers the promise of advancing POC diagnostics for all sexually transmitted infections.

Recommendations for the laboratory-based detection of Chlamydia trachomatis and Neisseria gonorrhoeae--2014

This report updates CDC's 2002 recommendations regarding screening tests to detect Chlamydia trachomatis and Neisseria gonorrhoeae infections (CDC. Screening tests to detect Chlamydia trachomatis and Neisseria gonorrhoeae infections-2002. MMWR 2002;51[No. RR-15]) and provides new recommendations regarding optimal specimen types, the use of tests to detect rectal and oropharyngeal C. trachomatis and N. gonorrhoeae infections, and circumstances when supplemental testing is indicated. The recommendations in this report are intended for use by clinical laboratory directors, laboratory staff, clinicians, and disease control personnel who must choose among the multiple available tests, establish standard operating procedures for collecting and processing specimens, interpret test results for laboratory reporting, and counsel and treat patients. The performance of nucleic acid amplification tests (NAATs) with respect to overall sensitivity, specificity, and ease of specimen transport is better than that of any of the other tests available for the diagnosis of chlamydial and gonococcal infections. Laboratories should use NAATs to detect chlamydia and gonorrhea except in cases of child sexual assault involving boys and rectal and oropharyngeal infections in prepubescent girls and when evaluating a potential gonorrhea treatment failure, in which case culture and susceptibility testing might be required. NAATs that have been cleared by the Food and Drug Administration (FDA) for the detection of C. trachomatis and N. gonorrhoeae infections are recommended as screening or diagnostic tests because they have been evaluated in patients with and without symptoms. Maintaining the capability to culture for both N. gonorrhoeae and C. trachomatis in laboratories throughout the country is important because data are insufficient to recommend nonculture tests in cases of sexual assault in prepubescent boys and extragenital anatomic site exposure in prepubescent girls. N. gonorrhoeae culture is required to evaluate suspected cases of gonorrhea treatment failure and to monitor developing resistance to current treatment regimens. Chlamydia culture also should be maintained in some laboratories to monitor future changes in antibiotic susceptibility and to support surveillance and research activities such as detection of lymphogranuloma venereum or rare infections caused by variant or mutated C. trachomatis.

A randomised trial of point-of-care tests for chlamydia and gonorrhoea infections in remote Aboriginal communities: Test, Treat ANd GO- the "TTANGO" trial protocol

BACKGROUND

High prevalence rates of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) have been reported in Aboriginal people in remote and regional areas of Australia for well over two decades, and repeat positivity rates are high. To interrupt disease transmission and reduce the risk of complications, early diagnosis and treatment is important. However in many remote and regional areas there are long delays between testing for these curable sexually transmissible infections and providing treatment, due to both physical distance from laboratories and difficulties when recalling patients for subsequent management once results are available. Point-of-care (POC) tests have the potential to provide more timely diagnosis, to increase treatment and contact tracing, and in turn reduce CT and NG infection rates.

METHODS/DESIGN

TTANGO (Test, Treat, ANd GO) is a cross-over cluster randomised controlled trial in 12 regional or remote Australian health services, which predominantly provide clinical services to Aboriginal people. The overall aim of TTANGO is to measure the clinical effectiveness, cost-effectiveness and cultural and operational acceptability of molecular POC testing for CT and NG infection. The primary outcome is repeat positivity at three months after treatment of an initial CT or NG infection. Participating health services will undertake the clinical management of CT and NG under two different modalities for one year each. In the first year, six health services will be randomly assigned to manage these infections under current diagnostic guidelines. The other six will supplement current diagnostic guidelines with POC testing, whereby diagnosis is made and subsequent treatment for those with positive POC tests is offered at the initial consultation. In the second year, the health services will cross over to the opposite management modality. TTANGO will be conducted over four years; 1.5 years of trial initiation and community consultation, 2 years of trial conditions and evaluation, and 6 months of data analysis and feedback.

DISCUSSION

TTANGO is the first cluster randomised trial of POC testing for CT and NG internationally. The results of this trial will provide crucial information to guide sexual health clinical practice in remote Aboriginal communities and other high prevalence settings.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry ACTRN12613000808741.

Point-of-care testing improves accuracy of STI care in an emergency department

OBJECTIVES

We aimed to examine the impact of a point-of-care (POC) test on overtreatment and undertreatment of sexually transmitted infections (STIs) by comparing treatment patterns for gonorrhoea (detected with nucleic acid amplification testing (NAAT)) with trichomoniasis (detected by POC test) for young women seen in an emergency department (ED).

METHODS

We reviewed the database of a quality improvement (QI) project that aims to improve follow-up care for STIs in the ED. Data included the test result and antibiotic given (if any) during visits by women age 14-21 for whom an STI test was ordered. We generated Shewhart control charts and compared overtreatment and undertreatment rates for gonorrhoea and trichomoniasis using χ(2) testing.

RESULTS

Of 1877 visits over 18 months, 8.8% of women had gonorrhoea and 16.5% had trichomoniasis. Overtreatment was higher for women with gonorrhoea than trichomoniasis (54% vs 23%, p<0.001). Overtreatment for gonorrhoea decreased from 58% to 47% (p<0.01) and overtreatment for trichomoniasis decreased from 24% to 18% (p<0.01), which corresponded to improvements in patient follow-up for the QI project. Undertreatment was higher for women with gonorrhoea than trichomoniasis (29% vs 21%, p=0.03), and did not change over time.

CONCLUSIONS

A POC test improves the accuracy of STI care in an ED compared with NAAT testing. An unanticipated benefit of QI efforts to improve patient follow-up is the observed decrease in antibiotic use in the ED. Given the ability of gonorrhoea to develop antibiotic resistance, future efforts should focus on development of an accurate POC test for gonorrhoea.

Priority interventions to reduce HIV transmission in sex work settings in sub-Saharan Africa and delivery of these services

Introduction

Virtually no African country provides HIV prevention services in sex work settings with an adequate scale and intensity. Uncertainty remains about the optimal set of interventions and mode of delivery.

Methods

We systematically reviewed studies reporting interventions for reducing HIV transmission among female sex workers in sub-Saharan Africa between January 2000 and July 2011. Medline (PubMed) and non-indexed journals were searched for studies with quantitative study outcomes.

Results

We located 26 studies, including seven randomized trials. Evidence supports implementation of the following interventions to reduce unprotected sex among female sex workers: peer-mediated condom promotion, risk-reduction counselling and skills-building for safer sex. One study found that interventions to counter hazardous alcohol-use lowered unprotected sex. Data also show effectiveness of screening for sexually transmitted infections (STIs) and syndromic STI treatment, but experience with periodic presumptive treatment is limited. HIV testing and counselling is essential for facilitating sex workers’ access to care and antiretroviral treatment (ART), but testing models for sex workers and indeed for ART access are little studied, as are structural interventions, which create conditions conducive for risk reduction. With the exception of Senegal, persistent criminalization of sex work across Africa reduces sex workers’ control over working conditions and impedes their access to health services. It also obstructs health-service provision and legal protection.

Conclusions

There is sufficient evidence of effectiveness of targeted interventions with female sex workers in Africa to inform delivery of services for this population. With improved planning and political will, services – including peer interventions, condom promotion and STI screening – would act at multiple levels to reduce HIV exposure and transmission efficiency among sex workers. Initiatives are required to enhance access to HIV testing and ART for sex workers, using current CD4 thresholds, or possibly earlier for prevention. Services implemented at sufficient scale and intensity also serve as a platform for subsequent community mobilization and sex worker empowerment, and alleviate a major source of incident infection sustaining even generalized HIV epidemics. Ultimately, structural and legal changes that align public health and human rights are needed to ensure that sex workers on the continent are adequately protected from HIV.

Point-of-care tests for the diagnosis of Neisseria gonorrhoeae infection: a systematic review of operational and performance characteristics

OBJECTIVES

Systematic review of the performance and operational characteristics of point-of-care (POC) tests for the diagnosis of Neisseria gonorrhoeae.

METHODS

We searched PubMed and Embase until August 2010 using variations of the terms: 'rapid test', 'Neisseria gonorrhoeae' and 'evaluation'.

RESULTS

We identified 100 papers, 14 studies were included; nine evaluated leucocyte esterase (LE) dipsticks and three immunochromatographic strips, and two clinical audits of microscopy were identified. Of the field evaluations the gold standard was nucleic acid amplification technology in six studies and bacterial culture in the other six. In four studies, 50% or more of the patients were symptomatic. The median sensitivity of LE dipsticks was 71% (range 23-85%), median specificity was 70% (33-99%), median positive predictive value (PPV) was 19% (5-40%) and median negative predictive value (NPV) was 95% (56-99%). One LE study found a sensitivity of 23% overall, increasing to 75% in symptomatic women. LE dipsticks mostly involved three steps and took under 2 min. The median sensitivity of immunochromatographic tests (ICT) was 70% (60-94%), median specificity was 96% (89-97%), median PPV was 56% (55-97%) and median NPV was 93% (92-99%). Immunochromatic strips involved five to seven steps and took 15-30 min. Specificity of microscopy ranged from 38% to 89%.

CONCLUSIONS

ICT and LE tests had similar sensitivities, but sensitivity results may be overestimated as largely symptomatic patients were included in some studies. ICT had a higher specificity in women than LE tests. The findings highlight the need for improved POC tests for diagnosis of N gonorrhoeae and more standardised evaluations.

A laboratory-based evaluation of the BioStar Optical ImmunoAssay point-of-care test for diagnosing Neisseria gonorrhoeae infection

The development of gonococcal point-of-care tests (POCTs) has been challenging due to the relatively monomorphic nature of the Neisseria genus. The BioStar Optical ImmunoAssay (OIA) POCT for diagnosing Neisseria gonorrhoeae infection detects a specific epitope on the L7/L12 ribosomal protein, which reduces cross-reactivity with other neisseriae, and produces a highly specific test. A laboratory-based evaluation of this POCT was performed to determine its analytical sensitivity and specificity. A panel of N. gonorrhoeae (n=158) and non-gonococcal Neisseria (n=62) isolates were examined. The OIA GC POCT positively reacted with 99.4% of N. gonorrhoeae isolates and produced no reaction with 88.7% of non-gonococcal Neisseria isolates. It cross-reacted with six strains of N. meningitidis and one non-speciated Neisseria sp., but failed to produce a positive result with one isolate of N. gonorrhoeae. The OIA GC POCT required a bacterial suspension of ~6.4×10(5) c.f.u. N. gonorrhoeae ml(-1) and ~6.2×10(6) c.f.u. N. meningitidis ml(-1) to produce a reactive result. The OIA POCT detected the majority of N. gonorrhoeae (99.4%) isolates examined.

What's the Point? How Point-of-Care STI Tests Can Impact Infected Patients

Point-of-care (POC) tests are an important strategy to address the epidemic of sexually transmitted infections (STIs) among both adolescents and young adults. While access to care and confidentiality are major barriers to STI care, POC tests allow the clinician to provide immediate and confidential test results and treatment. In addition, POC test results constitute a "teachable moment"; that is, an opportunity to provide immediate feedback to the patient that may impact his/her risk behaviors. This paper reviews published data and manufacturer's product literature describing current point-of-care STI tests, including studies of test performance as well as impact on treatment intervals and disease spread. It presents theoretical and proposed pitfalls and solutions of implementing POC tests in clinical settings, non-traditional settings, and home care venues. We reviewed the available STI tests according to the World Health Organization (WHO) criteria for judging POC tests: the "ASSURRED" criteria (Affordable, Sensitive, Specific, User-friendly, Rapid and Robust, Equipment-free, Delivered).

Diagnostic challenges of sexually transmitted infections in resource-limited settings

The global burden of sexually transmitted infections (STIs) is highest in the developing world where access to laboratory services is limited. Sophisticated laboratory diagnostic tests using noninvasive specimens have enabled developed countries to screen and diagnose curable STIs in a variety of settings, but control programs in resource-limited settings continue to struggle to find simple rapid tests that can provide adequate performance in the absence of laboratory services. While recent technological advances and investments in research and development may soon yield improved STI tests that can make an impact, these tests will need to be deployed within a health system that includes: regulatory oversight, quality assurance, good supply-chain management, effective training, information systems and a sound surveillance system to monitor disease trends, inform policy decisions and assess the impact of interventions.

Rapid diagnostic methods in sexually transmitted infections

Sexually transmitted infections (STIs) are common infections throughout the developed and the developing world. It is estimated that worldwide there are 1 million new cases per day of curable bacterial STIs. As part of the World Health Organization 2001 Sexually Transmitted Diseases Diagnostics Initiative, the organization explored the need for simple, affordable, point-of-care STI testing for curable bacterial STIs. This article reviews the evidence supporting the implementation of currently available rapid tests for five common STIs: syphilis, gonorrhea, chlamydia, HIV, and herpes.

Rapid tests for sexually transmitted infections (STIs): the way forward

In the developing world, laboratory services for sexually transmitted infections (STIs) are either not available, or where limited services are available, patients may not be able to pay for or physically access those services. Despite the existence of national policy for antenatal screening to prevent congenital syphilis and substantial evidence that antenatal screening is cost-effective, implementation of syphilis screening programmes remains unacceptably low because of lack of screening tools that can be used in primary health care settings. The World Health Organization Sexually Transmitted Diseases Diagnostics Initiative (SDI) has developed the ASSURED criteria as a benchmark to decide if tests address disease control needs: Affordable, Sensitive, Specific, User-friendly, Rapid and robust, Equipment-free and Deliverable to end-users. Rapid syphilis tests that can be used with whole blood approach the ASSURED criteria and can now be deployed in areas where no previous screening has been possible. Although rapid tests for chlamydia and gonorrhoea lack sensitivity, more tests are in development. The way forward for STI diagnostics requires a continuing quest for ASSURED tests, the development of a road map for test introduction, sustainable programmes for quality assurance, and the creation of a robust infrastructure linked to HIV prevention that ensures sustainability of STI control efforts that includes viral STIs.