Field evaluation of the performance and testing costs of a rapid point-of-care test for syphilis in a red-light district of Manaus, Brazil

An evaluation of barriers and facilitators to implementing multiplex rapid antigen testing for SARS-CoV-2 and influenza A and B in congregate living settings

Introduction

Point of care multiplex rapid antigen testing (RAT) is a tool that can be used to mitigate and respond to facility-based infectious disease outbreaks. However, little is known about how to optimally implement this testing in congregate living settings (CLSs), including long term care homes (LTCHs), retirement homes (RHs), and shelters serving people experiencing homelessness. Our objective was to explore the barriers and facilitators to implementing a new device for multiplex RAT for COVID-19 and influenza across CLSs in the Greater Toronto Area, Canada.

Materials and methods

Using key informant interviews, we assessed barriers and facilitators to implementing multiplex RAT across CLSs. Qualitative coding using the framework approach was used to identify themes. We used the Theoretical Domains Framework (TDF) and the Consolidated Framework for Implementation Research (CFIR) to identify individual and contextual-level barriers and facilitators to implementation. Identified barriers were then mapped to implementation strategies using theoretically-rooted frameworks and tools.

Results

We completed 45 interviews with staff at CLSs (8 LTCHs, 4 RHs, 12 shelters) between January 2022 and March 2023. Four barriers to RAT implementation in CLSs emerged including: limited material resources for implementation; insufficient staff capacity to perform RAT testing; complexity of RAT implementation; and reluctance among staff to adopt a new testing process. Five facilitators to implementation were described including: training and implementation support for staff at the CLSs; site-level implementation champions; access to materials to support testing; perceived advantages of simultaneous testing for COVID-19 and influenza; and the usability and functionality of the RAT testing device. Twenty implementation strategies were identified through implementation strategy mapping.

Discussion

Multiplex RAT options can empower CLS staff to promptly identify and respond to viral respiratory outbreaks. The use of evidence-based implementation strategies can enhance the effectiveness of using multiplex RAT to control outbreaks in CLSs.

Facilitators and barriers to point-of-care testing for sexually transmitted infections in low- and middle-income countries: a scoping review

BACKGROUND

Sexually transmitted infections (STIs) in low- and middle-income countries (LMICs) are predominantly managed by syndromic management. However, most STIs are asymptomatic. These untreated STIs cause individual morbidity, and lead to high STI prevalences. There is increasing interest in the use of point-of-care tests (POCTs) for STIs in LMICs, which could facilitate same day testing and treatment. To best utilise these tests, we must understand the facilitators and barriers to their implementation. The aim of this review is to explore how point-of-care testing for STIs has been implemented into healthcare systems in LMIC and the facilitators and barriers to doing so.

METHODS

A scoping review was conducted by searching MEDLINE, Embase, Emcare, CINAHL, Scopus, LILACS, the Cochrane Library, and ProQuest Dissertations and Theses for studies published between 1st January 1998 and 5th June 2020. Abstracts and full articles were screened independently by two reviewers. Studies were considered for inclusion if they assessed the acceptability, feasibility, facilitators, or barriers to implementation of point-of-care testing for chlamydia, gonorrhoea, trichomoniasis or syphilis in LMICs. Thematic analysis was used to analyse and present the facilitators and barriers to point-of-care STI testing.

RESULTS

The literature search revealed 82 articles suitable for inclusion; 44 (53.7%) from sub-Saharan Africa; 21 (25.6%) from Latin American and the Caribbean; 10 (12.2%) from East Asia and the Pacific; 6 (7.3%) from South Asia; and one (1.2%) multi-regional study. Thematic analysis revealed seven overarching themes related to the implementation of POCTs in LMICs, namely (i) Ideal test characteristics, (ii) Client factors, (iii) Healthcare provision factors, (iv) Policy, infrastructure and health system factors, (v) Training, audit, and feedback, (vi) Reaching new testing environments, and (vii) Dual testing.

CONCLUSION

Implementation of POCTs in LMICs is complex, with many of the barriers due to wider health system weakness. In addition to pressing for broader structural change to facilitate basic healthcare delivery, these themes may also be used as a basis on which to develop future interventions. The literature was heavily skewed towards syphilis testing, and so more research needs to be conducted assessing chlamydia, gonorrhoea, and trichomoniasis testing, as well as home or self-testing.

Diagnostic Accuracy of Rapid Point-of-Care Tests for Detecting Active Syphilis: A Systematic Review and Meta-Analysis

BACKGROUND

Syphilis represents an important cause of morbidity and mortality. Point-of-care (POC) test offers the advantages of diagnosing the condition and the possibility of starting treatment immediately.

METHODS

MEDLINE, Embase, CENTRAL, LILACS, World Health Organization International Clinical Trials Registry Platform, Web of Science, OpenGrey, and DARE were searched without language restrictions from inception to September 30, 2020. Diagnostic test accuracy studies that enrolled men and nonpregnant women of reproductive age under field conditions were analyzed. Only studies wherein all the patients had undergone a rapid POC test and those that included the reference standard (treponemal plus nontreponemal test) were eligible for inclusion. Studies were independently assessed for inclusion, data extraction, and bias risk. The data from these studies were extracted for meta-analyses. The quality of the evidence was assessed using the GRADE approach. Registration Prospero CRD42018107532.

RESULTS

Nine studies with 9666 participants were included. Nine POC brands were assessed. Sensitivities of the tests ranged from 0.67 to 1.00 and specificities from 0.93 to 1.00. The mean sensitivity and specificity of all the included studies was 0.86 (95% confidence interval, 0.79-0.91) and 0.98 (95% confidence interval, 0.96-0.99), respectively.

CONCLUSIONS

Based on the results of this systematic review, the POC test for syphilis showed good sensitivity and excellent specificity.

Cost-Effectiveness Analysis of Point-of-Care Rapid Testing Versus Laboratory-Based Testing for Antenatal Screening of Syphilis in Brazil

OBJECTIVES

Severe consequences of mother-to-child transmission of syphilis and high increasing incidence of congenital syphilis remains an important public health problem in Brazil. Our objective was to assess the cost-effectiveness of a rapid point-of-care test (RT) and treatment of positive mothers immediately compared with a laboratory-based standard test (ST) with treatment at next follow-up visit.

METHODS

A decision analytic model was developed to estimate the incremental cost-effectiveness ratio (ICER) between antenatal syphilis screening strategies. The model was built with lifetime horizon from Brazilian health system perspective using 3% and 5% discount rates. A hypothetical cohort of pregnant women at reproductive age were used in the model. Health outcomes: low birth weight, stillbirths, neonatal deaths and congenital syphilis were estimated in disability-adjusted life-years (DALYs) lost. Microcosting study and secondary data provided parameters of direct medical costs. Probabilistic sensitivity analysis was undertaken.

RESULTS

For base case, the mean cost per pregnant woman screened was $2.63 (RT) and $2.48 (ST), respectively. Maternal syphilis was associated with a loss of 0.0043 DALYs (RT) and 0.0048 DALYs (ST) per mother screened. Expected value of incremental cost per DALY averted was $298.08. After 10 000 probabilistic sensitivity analysis model runs, incremental cost and health benefits were $0.15 (95% credible interval -1.56 to 1.92) and 0.00042 DALYs (95% credible interval -0.0036 to 0.0044), respectively, with a mean ICER of $357.44 per DALY. Screening with RT has a 58% chance of being the optimal strategy at a threshold of $3,200 per DALY.

CONCLUSIONS

In Brazil, antenatal screening with syphilis RT and immediate treatment is likely to be cost-effective compared with standard screening and must be prioritized in local settings.

Rapid diagnostic tests for infectious diseases in the emergency department

Background

Rapid diagnostic tests (RDTs) for infectious diseases, with a turnaround time of less than 2 hours, are promising tools that could improve patient care, antimicrobial stewardship and infection prevention in the emergency department (ED) setting. Numerous RDTs have been developed, although not necessarily for the ED environment. Their successful implementation in the ED relies on their performance and impact on patient management.

Objectives

The aim of this narrative review was to provide an overview of currently available RDTs for infectious diseases in the ED.

Sources

PubMed was searched through August 2019 for available studies on RDTs for infectious diseases. Inclusion criteria included: commercial tests approved by the US Food and Drug Administration (FDA) or Conformité Européenne (CE) in vitro diagnostic devices with data on clinical samples, ability to run on fully automated systems and result delivery within 2 hours.

Content

A nonexhaustive list of representative commercially available FDA- or CE-approved assays was categorized by clinical syndrome: pharyngitis and upper respiratory tract infection, lower respiratory tract infection, gastrointestinal infection, meningitis and encephalitis, fever in returning travellers and sexually transmitted infection, including HIV. The performance of tests was described on the basis of clinical validation studies. Further, their impact on clinical outcomes and anti-infective use was discussed with a focus on ED-based studies.

Implications

Clinicians should be familiar with the distinctive features of each RDT and individual performance characteristics for each target. Their integration into ED work flow should be preplanned considering local constraints of given settings. Additional clinical studies are needed to further evaluate their clinical effectiveness and cost-effectiveness.

Association between Knowledge of Sexually Transmitted Infections and Sources of the Previous Point of Care among Nigerians: Findings from Three National HIV and AIDS Reproductive Health Surveys

Background. Adequate knowledge of sexually transmitted infections (STIs) is critical for effective control of disease. Health education/counselling at the point of care provides ample opportunities to improve knowledge of patient seeking treatment. There is no study from Nigeria that investigates association between sources of previous point of care of STI and quality of knowledge of people on STI. We hypothesised that previous treatment of STI will be associated with better knowledge of STI and HIV infection. Methods. Three consecutives nationally representative cross-sectional surveys on HIV and AIDS Reproductive Health in Nigeria, conducted in 2005, 2007, and 2012 were analysed. Outcome measures were knowledge of STI only, and a combined knowledge of STI and HIV transmission and prevention. We designed a knowledge scale of 14-item questions for STI and 41-item questions for STI and HIV. Logistic regression was used to identify risk factors at 5% significance level. Results. Knowledge of STI increased from 13.4% in 2005 to 15.0% in 2007 to 26.5% in 2012. Respondents that received treatment from pharmacy and patient medicine vendors had higher odds of good knowledge of STI than those who did not receive any treatment (aOR = 2.55) in 2005. In 2012, respondents treated at health facilities were over two times likely to have good knowledge of STI and HIV transmission and prevention (aOR = 2.35). STI positive individuals in the highest economic class were two times likely to have good knowledge of STI and HIV transmission and prevention than those in the lowest class. Conclusion. Participants that previously sought care from health facilities, pharmacy, and patient medicine vendors had better knowledge of STIs and HIV infection prevention and transmission than those who sought care from unorthodox sources. We recommend a national awareness creation on STI prevention including provision of information on safe point of care for STIs in Nigeria.

Laboratory assessment of SD Bioline HIV/Syphilis Duo Kit among pregnant women attending antenatal clinic Mayuge Health Center III, East central Uganda

OBJECTIVE

Efforts to dual eradication of mother-to-child transmission of human immune deficiency virus (HIV) and syphilis have improved in the previous decades. This has however been hindered by limited validation studies. A cross-sectional study was conducted among adult pregnant women attending antenatal care clinic at Mayuge Health Center III. Two milliliters of venous blood were collected into Ethylene di-amine tetra acetic acid vacutainers, and tested for HIV and syphilis using the SD Bioline HIV/Syphilis Duo assay, and the national HIV and syphilis testing algorithm. Sensitivity and specificity were calculated for the Duo Kit against the gold standards within 95% confidence intervals.

RESULTS

Three hundred and eighty-two (382) participants were enrolled. Their mean age was 25.8 years. The prevalence of HIV was 1.8% (95% confidence interval 1.23-2.41); while that of syphilis was 2.1% (95% confidence interval 1.81-2.54), and the dual infection was 0.52% (95% confidence interval 0.37-0.92). The sensitivity and specificity of the SD Bioline HIV/Syphilis Duo assay were all 100.0% (95% confidence interval 99.5 to 100.0 and 98.6 to 100.0, respectively). The performance of the SD Bioline HIV/Syphilis Duo Kit was optimal, reassuring its aptness for use, and favorable qualities to a limited resource setting.

Bior B, W. Dumo G, S. Katoro J, Mogga JJH, Lokore ML, G. Abias A, Y. Carter J, L. Deng L. Field evaluation of SD BIOLINE HIV/Syphilis Duo assay among pregnant women attending routine antenatal care in Juba, South Sudan

The SD BIOLINE HIV/Syphilis Duo assay is the first World Health Organization prequalified dual rapid diagnostic test for simultaneous detection of HIV and Treponema pallidum antibodies in human blood. Prior to introducing the test into antenatal clinics across South Sudan, a field evaluation of its clinical performance in diagnosing both HIV and syphilis in pregnant women was conducted. SD Bioline test performance on venous blood samples was compared with (i) Vironostika HIV1/2 Uniform II Ag/Ab reference standard and Alere Determine HIV 1/2 non-reference standard for HIV diagnosis, and (ii) Treponema pallidum hemagglutination reference standard and Rapid plasma reagin non-reference standard for syphilis. Sensitivity, specificity, positive predictive value (PPN), negative predictive value (NPV) and kappa (κ) value were calculated for each component against the reference standards within 95% confidence intervals (CIs); agreements between Determine HIV 1/2 and SD Bioline HIV tests were also calculated. Of 442 pregnant women recruited, eight (1.8%) were HIV positive, 22 (5.0%) had evidence of syphilis exposure; 14 (3.2%) had active infection. For HIV diagnosis, the sensitivity, specificity, PPV and NPV were 100% (95% CI: 63.1–100), 100% (95% CI: 99.2–100), 100% (95% CI: 63.1–100) and 100% (95% CI: 99.2–100) respectively with κ value of 1 (95% CI: 0.992–1.000). Overall agreement of the Duo HIV component and Determine test was 99.1% (95% CI: 0.977–0.998) with 66.7% (95% CI: 34.9–90.1) positive and 100% (95% CI: 0.992–1.000) negative percent agreements. For syphilis, the Duo assay sensitivity was 86.4% (95% CI: 65.1–97.1) and specificity 100% (95% CI: 99.1–100) with PPV 100% (95% CI: 82.4–100), NPV 99.2% (95% CI: 97.9–99.9) and κ value 0.92 (95% CI: 0.980–0.999). Our findings suggest the SD Bioline HIV/Syphilis Duo Assay could be suitable for HIV and syphilis testing in women attending antenatal services across South Sudan. Women with positive syphilis results should receive treatment immediately, whereas HIV positive women should undergo confirmatory testing following national HIV testing guidelines.

Laboratory Evaluation of a Commercially Available Rapid Syphilis Test

Serological diagnosis of syphilis depends on assays that detect treponemal and nontreponemal antibodies. Laboratory certification and trained personnel are needed to perform most of these tests, while high costs and long turnaround time can hinder treatment initiation or linkage to care. A rapid treponemal syphilis test (RST) that is simple to perform, accessible, and inexpensive would be ideal. The Syphilis Health Check (SHC) assay is the only Food and Drug Administration (FDA)-cleared and Clinical Laboratory Improvement Amendments (CLIA)-waived RST in the United States. In this study, 1,406 archived human serum samples were tested using SHC and traditional treponemal and nontreponemal assays. Rapid test results were compared with treponemal data alone and with a laboratory test panel consensus defined as being reactive by both treponemal and nontreponemal assays for a given specimen, or nonreactive by both types of assays. The sensitivity and specificity of the SHC assay compared with treponemal tests alone were 88.7% (95% confidence interval [CI], 86.2 to 90.0%) and 93.1% (95% CI, 90.0 to 94.9%), respectively, while comparison with the laboratory test panel consensus showed 95.7% (95% CI, 93.6 to 97.2%) sensitivity and 93.2% (95% CI, 91.0 to 95.1%) specificity. The data were further stratified based on age, sex, pregnancy, and HIV status. The sensitivity and specificity of the SHC assay ranged from 66.7% (95% CI, 46.0 to 83.5%) to 91.7% (95% CI, 87.7 to 94.7%) and 88% (95% CI, 68.8 to 97.5%) to 100% (95% CI, 47.8 to 100%), respectively, across groups compared to traditional treponemal assays, generally increasing for all groups except the HIV-positive (HIV+) population when factoring in the laboratory test panel consensus. These data contribute to current knowledge of the SHC assay performance for distinct populations and may guide use in various settings.

Systematic Review of Health Economic Evaluations of Diagnostic Tests in Brazil: How accurate are the results?

The aim of this study is to identify and characterize the health economic evaluations (HEEs) of diagnostic tests conducted in Brazil, in terms of their adherence to international guidelines for reporting economic studies and specific questions in test accuracy reports. We systematically searched multiple databases, selecting partial and full HEEs of diagnostic tests, published between 1980 and 2013. Two independent reviewers screened articles for relevance and extracted the data. We performed a qualitative narrative synthesis. Forty-three articles were reviewed. The most frequently studied diagnostic tests were laboratory tests (37.2%) and imaging tests (32.6%). Most were non-invasive tests (51.2%) and were performed in the adult population (48.8%). The intended purposes of the technologies evaluated were mostly diagnostic (69.8%), but diagnosis and treatment and screening, diagnosis, and treatment accounted for 25.6% and 4.7%, respectively. Of the reviewed studies, 12.5% described the methods used to estimate the quantities of resources, 33.3% reported the discount rate applied, and 29.2% listed the type of sensitivity analysis performed. Among the 12 cost-effectiveness analyses, only two studies (17%) referred to the application of formal methods to check the quality of the accuracy studies that provided support for the economic model. The existing Brazilian literature on the HEEs of diagnostic tests exhibited reasonably good performance. However, the following points still require improvement: 1) the methods used to estimate resource quantities and unit costs, 2) the discount rate, 3) descriptions of sensitivity analysis methods, 4) reporting of conflicts of interest, 5) evaluations of the quality of the accuracy studies considered in the cost-effectiveness models, and 6) the incorporation of accuracy measures into sensitivity analyses.

Field evaluation of Standard Diagnostics' Bioline HIV/Syphilis Duo test among female sex workers in Johannesburg, South Africa

BACKGROUND

Point-of-care tests provide immediate results with the opportunity for same-day interventions with improved public health outcomes. A dual HIV/syphilis test enables early treatment of both diseases.

METHODS

We conducted a field evaluation of the Standard Diagnostics' SD Bioline HIV/Syphilis Duo test (SD Bioline) among female sex workers. SD Bioline was conducted on finger-prick blood according to manufacturer's instructions and compared with (i) Genscreen HIV1/2 (third generation) and Vironostika Ag/Ab (fourth generation) assays for HIV, and (ii) Treponema pallidum particle agglutination (TPPA) and rapid plasma reagin (RPR) assays for syphilis. A negative TPPA test was considered negative, a TPPA-confirmed RPR titre ≤1:4 as past infection and a TPPA-confirmed RPR titre ≥1:8 as active syphilis. Sensitivity, specificity, positive and negative predictive values were calculated.

RESULTS

Of 263 women recruited, 14 (5.3%) declined an HIV test. Among the remaining 249 women, 187 (75.1%) were HIV positive, 51 (20.5%) had syphilis antibodies with seven (2.8%) active infections. For HIV, the sensitivity and specificity were 98.9% (95% CI 95.8% to 99.8%) and 100% (95% CI 92.7% to 100%). For syphilis, the sensitivity and specificity were 66.7% (95% CI 52.0% to 78.9%) and 98.0% (95% CI 94.5% to 99.3%). Sera with high TPPA titres were more likely to test positive.

CONCLUSIONS

In field conditions, while the SD Bioline test has high sensitivity and specificity for HIV and high specificity for syphilis, the test has lower sensitivity for syphilis than reported from laboratory evaluations. As the dual test detects only two thirds of syphilis cases, it should only be used in areas with weak screening programmes.

"I Do Feel Like a Scientist at Times": A Qualitative Study of the Acceptability of Molecular Point-Of-Care Testing for Chlamydia and Gonorrhoea to Primary Care Professionals in a Remote High STI Burden Setting

Background

Point-of-care tests for chlamydia (CT) and gonorrhoea (NG) could increase the uptake and timeliness of testing and treatment, contribute to improved disease control and reduce reproductive morbidity. The GeneXpert (Xpert CT/NG assay), suited to use at the point-of-care, is being used in the TTANGO randomised controlled trial (RCT) in 12 remote Australian health services with a high burden of sexually transmissible infections (STIs). This represents the first ever routine use of a molecular point-of-care diagnostic for STIs in primary care. The purpose of this study was to explore the acceptability of the GeneXpert to primary care staff in remote Australia.

Methods

In-depth qualitative interviews were conducted with 16 staff (registered or enrolled nurses and Aboriginal Health Workers/Practitioners) trained and experienced with GeneXpert testing. Interviews were digitally-recorded and transcribed verbatim prior to content analysis.

Results

Most participants displayed positive attitudes, indicating the test was both easy to use and useful in their clinical context. Participants indicated that point-of-care testing had improved management of STIs, resulting in more timely and targeted treatment, earlier commencement of partner notification, and reduced follow up efforts associated with client recall. Staff expressed confidence in point-of-care test results and treating patients on this basis, and reported greater job satisfaction. While point-of-care testing did not negatively impact on client flow, several found the manual documentation processes time consuming, suggesting that improved electronic connectivity and test result transfer between the GeneXpert and patient management systems could overcome this. Managing positive test results in a shorter time frame was challenging for some but most found it satisfying to complete episodes of care more quickly.

Conclusions

In the context of a RCT, health professionals working in remote primary care in Australia found the GeneXpert highly acceptable. These findings have implications for use in other primary care settings around the world.

Prevalence of syphilis and associated factors in homeless people of Sao Paulo, Brazil, using a Rapid Test

INTRODUCTION

Homeless people are a vulnerable group to sexually transmitted diseases (STD) with high prevalence of syphilis and hepatitis.

OBJECTIVES

To estimate the prevalence of syphilis infection and its association with risky behaviors for STDs in a sample of homeless people, and to assess the feasibility of the use of rapid syphilis test (RST) in this population.

METHODS

Cross-sectional study, in a convenience sample of homeless people assisted in social support services of São Paulo, between 2006 and 2007. A structured questionnaire was applied and RST was performed. In addition, a blood sample for syphilis detection was also collected. The sensitivity and specificity of the RST was estimated using conventional laboratory diagnosis (VDRL + TPHA) as reference.

RESULTS

1,405 volunteers were included in the study. The prevalence rate of syphilis was 7.0%, and was associated with homosexual practices (OR(adj) 4.9; 95%CI 2.6 - 9.4), prior history of STD (OR(adj) 2.6; 95%CI 1.7 - 4.0) and with self-referred non-white race (OR(adj) 1.9; 95%CI 1.1 - 3.4). The sensitivity and specificity of the RST for syphilis were, respectively, 81.4 and 92.1%.

CONCLUSION

The high prevalence of syphilis infection among homeless people shows the need for actions for its control and the utilization of RST that can be considered an efficient strategy due to its sensitivity and specificity. Public Health policymakers must strengthen actions for syphilis control, with screening tests for syphilis and early treatment, decreasing morbidity with the improvement of sexual and reproductive health of the population in general and especially the most vulnerable.

Point-of-care screening for syphilis and HIV in the borderlands: challenges in implementation in the Brazilian Amazon

Background

Point-of-care (POC) screening for HIV and syphilis using rapid testing was implemented in indigenous communities in the triple-border area of the Brazilian Amazon. We describe the context of the early introduction of POC screening, explore hindering and enabling factors for POC implementation, and recommend strategies for feasible, viable, and sustainable syphilis and HIV screening interventions.

Methods

This was a qualitative study based on grounded theory methodology. Data were collected using in-depth interviews, semi-structured questionnaires, and field observations and were analysed using the framework approach. Qualitative information was complemented by quantitative data for descriptive purposes.

Results

An overall high score for vulnerability to acquiring HIV and syphilis was observed among the indigenous communities. Health professionals reported satisfactory rapid testing acceptance, although concerns were raised about the pain of the fingerprick. Counselling-related challenges included ensuring the accuracy of translations, collaborating with translators and communicating positive test results. Over 3 months, 86.7 % of the syphilis-positive individuals began treatment, and all of them notified their partners. Accessibility, measured as travel time via the local transportation network, was a barrier to health care access. A lack of gasoline for boats and other transportation was also a hindering factor at all levels of implementation.

Conclusions

The recommendations address the preparation phase at the coordination level as well as at the training level. Tools such as strengths, weaknesses, opportunities, and threats (SWOT) analyses; checklists; context-adapted protocols; and fact sheets are very simple methods to facilitate implementation. The findings of this study are important because they may inform the implementation of new health technologies in low-resource national disease control programmes in remote communities.

HIV/AIDS epidemic in the State of Amazonas: characteristics and trends from 2001 to 2012

A scoping review was conducted to describe the epidemiological characteristics of the human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) epidemic in the State of Amazonas, Brazil, from 2001 to 2012, and temporary patterns were estimated from surveillance data. The results suggest that in its third decade, the Amazon HIV/AIDS epidemic is far from being stabilized and displays rising AIDS incidence and mortality rates and late diagnoses. The data suggest that AIDS cases are hitting mostly young adults and have recently shifted toward men, both homosexual and heterosexual. AIDS cases among the indigenous people have remained stable and low. However, the epidemic has disseminated to the interior of the state, which adds difficulties to its control, given the geographical isolation, logistical barriers, and culturally and ethnically diverse population. Antiretroviral (ARV) therapy has been decentralized, but peripheral ARV services are still insufficient and too distant from people who need them. Recently, the expansion of point-of-care (POC) rapid HIV testing has been contributing to overcoming logistical barriers. Other new POC devices, such as the PIMA CD4 analyzer, will bring the laboratory to the patient. AIDS uniquely coexists with other tropical infections, sharing their epidemiological profiles. The increased demand for HIV/AIDS care services can only be satisfied through increased decentralization to peripheral health units, which can also naturally integrate care with other tropical infections and can promote a shift from vertical to integrated programming. Future challenges involve building surveillance data on HIV case notification and covering the spectrum of engagement in care, including adherence to treatment and follow-up loss.

Diagnostic accuracy of rapid tests for sexually transmitted infections in symptomatic women

OBJECTIVE

To determine the diagnostic accuracy of tests developed for use at the point of care for Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and syphilis in women having symptoms of lower urinary tract infection.

METHODS

Cross-sectional study involving sexually active 14-49-year-old women with lower urinary tract infection symptoms consulting during 2010 at a private health clinic and at two public hospitals in Bogotá, Colombia. Pregnant women, those with a previous hysterectomy or those who received antibiotics during the previous 7 days were excluded. Sequential sampling was used; sample size: 1500 women. The ACON NG and CT duo test combo and the ACON individual test plates for NG and separately for CT were used. The QuickVue Chlamydia rapid test (RT) was also used. All of them were compared with nucleic acid amplification methods. The SD Bioline 3.0 and ACON test for syphilis were evaluated and compared with serological tests. Sensitivity and specificity were estimated.

RESULTS

CT RTs had a sensitivity that ranged between 22.7% and 37.7% and specificity between 99.3% and 100%. Sensitivity for NG with ACON Duo was 12.5% and specificity 99.8%. Tests for syphilis had a sensitivity of 91.6-100% and a specificity of 99.7-97.8%.

CONCLUSIONS

The RTs studied are not useful for screening for NG at the point of care. In case of CT a recommendation about their use in routine care should be supported by a cost-effectiveness analysis. In screening populations at high risk of sexually transmitted infections or pregnant women, the RTs for syphilis should be used.

Canadian Public Health Laboratory Network laboratory guidelines for the use of point-of-care tests for the diagnosis of syphilis in Canada

Syphilis point-of-care tests (POCT) are widely available in developing countries enabling early diagnosis, treatment and support. The majority of commercially available tests use treponemal antigens and the presence of antibodies does not distinguish between current and past infection, which may lead to unnecessary antibiotic use and stigmatization of having a current STI. In hard-to-reach populations, the benefits may outweigh the risks. Available studies show reasonable performance of POCT with median sensitivity of 86%, specificity of 99% and positive predictive values >80% when prevalence was >0.3%. Although no syphilis POCT are approved in Canada at this time, a single study in an outreach setting in Alberta showed limited benefit due to a high prevalence of previous infection but more studies are needed. Newer dual tests employing treponemal and nontreponemal antigens look promising.

Recent trends in the serologic diagnosis of syphilis

Complexities in the diagnosis of syphilis continue to challenge clinicians. While direct tests (e.g., microscopy or PCR) are helpful in early syphilis, the mainstay of diagnosis remains serologic tests. The traditional algorithm using a nontreponemal test (NTT) followed by a treponemal test (TT) remains the standard in many parts of the world. More recently, the ability to automate the TT has led to the increasingly widespread use of reverse algorithms using treponemal enzyme immunoassays (EIAs). Rapid, point-of-care TTs are in widespread use in developing countries because of low cost, ease of use, and reasonable performance. However, none of the current diagnostic algorithms are able to distinguish current from previously treated infections. In addition, the reversal of traditional syphilis algorithms has led to uncertainty in the clinical management of patients. The interpretation of syphilis tests is further complicated by the lack of a reliable gold standard for syphilis diagnostics, and the newer tests can result in false-positive reactions similar to those seen with older tests. Little progress has been made in the area of serologic diagnostics for congenital syphilis, which requires assessment of maternal treatment and serologic response as well as clinical and laboratory investigation of the neonate for appropriate management. The diagnosis of neurosyphilis continues to require the collection of cerebrospinal fluid for a combination of NTT and TT, and, while newer treponemal EIAs look promising, more studies are needed to confirm their utility. This article reviews current tests and discusses current controversies in syphilis diagnosis, with a focus on serologic tests.

Poor Reporting of Outcomes Beyond Accuracy in Point-of-Care Tests for Syphilis: A Call for a Framework

Background. Point-of-care (POC) diagnostics for syphilis can contribute to epidemic control by offering a timely knowledge of serostatus. Although accuracy data on POC syphilis tests have been widely published, few studies have evaluated broader outcomes beyond accuracy that impact patients and health systems. We comprehensively reviewed evidence and reporting of these implementation research outcomes (IROs), and proposed a framework to improve their quality. Methods. Three reviewers systematically searched 6 electronic databases from 1980 to 2014 for syphilis POC studies reporting IROs. Data were abstracted and findings synthesised narratively. Results. Of 71 studies identified, 38 documented IROs. IROs were subclassified into preference (7), acceptability (15), feasibility (15), barriers and challenges (15), impact (13), and prevalence (23). Using our framework and definitions, a pattern of incomplete documentation, inconsistent definitions, and lack of clarity was identified across all IROs. Conclusion. Although POC screening tests for syphilis were generally favourably evaluated across a range of outcomes, the quality of evidence was compromised by inconsistent definitions, poor methodology, and documentation of outcomes. A framework for standardized reporting of outcomes beyond accuracy was proposed and considered a necessary first step towards an effective implementation of these metrics in POC diagnostics research.

The endemic treponematoses

The agents of human treponematoses include four closely related members of the genus Treponema: three subspecies of Treponema pallidum plus Treponema carateum. T. pallidum subsp. pallidum causes venereal syphilis, while T. pallidum subsp. pertenue, T. pallidum subsp. endemicum, and T. carateum are the agents of the endemic treponematoses yaws, bejel (or endemic syphilis), and pinta, respectively. All human treponematoses share remarkable similarities in pathogenesis and clinical manifestations, consistent with the high genetic and antigenic relatedness of their etiological agents. Distinctive features have been identified in terms of age of acquisition, most common mode of transmission, and capacity for invasion of the central nervous system and fetus, although the accuracy of these purported differences is debated among investigators and no biological basis for these differences has been identified to date. In 2012, the World Health Organization (WHO) officially set a goal for yaws eradication by 2020. This challenging but potentially feasible endeavor is favored by the adoption of oral azithromycin for mass treatment and the currently focused distribution of yaws and endemic treponematoses and has revived global interest in these fascinating diseases and their causative agents.

Diagnostic point-of-care tests in resource-limited settings

The aim of diagnostic point-of-care testing is to minimise the time to obtain a test result, thereby allowing clinicians and patients to make a quick clinical decision. Because point-of-care tests are used in resource-limited settings, the benefits need to outweigh the costs. To optimise point-of-care testing in resource-limited settings, diagnostic tests need rigorous assessments focused on relevant clinical outcomes and operational costs, which differ from assessments of conventional diagnostic tests. We reviewed published studies on point-of-care testing in resource-limited settings, and found no clearly defined metric for the clinical usefulness of point-of-care testing. Therefore, we propose a framework for the assessment of point-of-care tests, and suggest and define the term test efficacy to describe the ability of a diagnostic test to support a clinical decision within its operational context. We also propose revised criteria for an ideal diagnostic point-of-care test in resource-limited settings. Through systematic assessments, comparisons between centralised testing and novel point-of-care technologies can be more formalised, and health officials can better establish which point-of-care technologies represent valuable additions to their clinical programmes.

State of the art syphilis diagnostics: rapid point-of-care tests

Syphilis remains an important and entirely preventable cause of stillbirth and neonatal mortality. More than 1 million women with active syphilis become pregnant each year. Without treatment, 25% of them will deliver a stillborn baby, 33% will deliver a live low-birth weight baby with an increased chance of dying in the first month of life. Adverse pregnancy outcomes due to syphilis can be prevented by screening pregnant women, and treating those who test positive with a single dose of penicillin before 28 weeks gestation. Until recently access to screening in low- and middle-income countries has been limited, since screening tests have been laboratory based, requiring equipment, electricity and trained laboratory staff. Now a number of rapid, cheap, simple and accurate screening tests are available and can give a result in 15-20 min, enabling those who require treatment to be treated at their first visit.

Modern immunochromatographic methods for determination of anti-treponema pallidum antigenantibodies

The authors present a review of research publications about clinical significance of using modern immunochromatographic methods for determination of anti-immunodominant antigen antibodies of syphilis pathogen Treponema pallidum. Immunochromatographic sets of chemicals proved to be convenient in use, can be used with a small amount of biological materials, do not demand any specialized medical equipment, have high sensitivity and specificity, in particular, for tests with blood serum or plasma samples; when whole blood samples are used, this reduces the method sensitivity. Immunochromatographic tests are intended for prompt express examination of the population to reveal syphilis patients under field conditions or at medical institutions consulting primary patients and not having their own clinical laboratories.

Field performance of a rapid point-of-care diagnostic test for antenatal syphilis screening in the Amazon region, Brazil

We evaluated an immunochromatographic point-of-care (POC) syphilis test in 712 pregnant women under field conditions in remote communities of the Amazon region (Brazil), and identified risk factors for syphilis. Women were screened by POC test using whole blood obtained by fingerprick, the fluorescent treponemal antibody absorption (FTA-Abs) test as the gold standard and the Venereal Diseases Research Laboratory (VDRL) test to determine test performance in active syphilis. Multivariate analysis was conducted to identify factors associated with syphilis infection. Among women, 2.2% had syphilis (positive FTA-Abs) and 0.8% active syphilis (FTA-Abs and VDRL positive). In all, 2.2% of samples were positive by the POC test. The sensitivity, specificity, positive and negative predictive values were 62.5% (95% confidence interval [CI]: 38.6-81.5), 99.1% (95% CI: 98.1-99.6), 62.5% (95% CI: 38.6-81.5) and 99.1% (95% CI: 98.1-99.6), respectively. The POC test identified 62.5% (10/16) of syphilis cases, 66.7% (4/6) of active syphilis cases and all high-titre syphilis cases (VDRL > 1:8). Older age was associated with syphilis infection. The rapid test performed moderately well as a screening tool for low-risk populations. This combined with on-site testing and same day treatment could expand antenatal syphilis screening programmes in distant communities characterized by difficult access to antenatal services and infrequent clinical follow-up visits.

HIV prevalence among female sex workers, drug users and men who have sex with men in Brazil: a systematic review and meta-analysis

Background

The Brazilian response towards AIDS epidemic is well known, but the absence of a systematic review of vulnerable populations ─ men who have sex with men (MSM), female sex workers (FSW), and drug users (DU) remains a main gap in the available literature. Our goal was to conduct a systematic review and meta-analysis of studies assessing HIV prevalence among MSM, FSW and DU, calculating a combined pooled prevalence and summarizing factors associated the pooled prevalence for each group.

Methods

Nine electronic databases (MEDLINE via PubMed, EMBASE, Cochrane CENTRAL, AIDSLINE, AMED, CINAHL, TOXNET, SciELO, and ISI-Web of Science) were searched for peer-reviewed papers published in English, French, Spanish or Portuguese, from 1999 to 2009. To be included in the review, studies had to measure HIV prevalence and/or incidence as the primary outcome among at least one specific population under analysis.

Results

The studies targeting the three populations analyzed mostly young participants aged 30 years or less. Among FSW, eight studies were selected (3,625 participants), consistently identifying higher condom use with sexual clients than with occasional and stable partners. The combined HIV prevalence for FSW was 6.2 (95% CI: 4.4-8.3). Ten studies targeting MSM were identified (6,475 participants). Unprotected anal intercourse was commonly reported on those studies, but with great variability according to the nature of the relationship - stable vs. occasional sex partners - and sexual practice - receptive vs. insertive anal sex. Pooled HIV prevalence for MSM was 13.6 (95% CI: 8.2-20.2). Twenty nine studies targeting DU were identified (13,063 participants). Those studies consistently identified injection drug use and syringe/needle sharing as key predictors of HIV-infection, as well as engagement in sex work and male-to-male sex. The combined HIV prevalence across studies targeting DU was 23.1 (95% CI: 16.7-30.2).

Conclusions

FSW, MSM and DU from Brazil have a much risk of acquiring HIV infection compared to the general population, among which HIV prevalence has been relatively low (~0.6%). Those vulnerable populations should be targeted by focused prevention strategies that provide accurate information, counseling and testing, as well as concrete means to foster behavior change (e.g. access to condoms, drug abuse treatment, and clean syringes in the case of active injecting drug users), tailored to gender and culture-specific needs. Programs that provide these services need to be implemented on public health services throughout the country, in order to decrease the vulnerability of those populations to HIV infection.

Rapid point-of-care diagnostic test for syphilis in high-risk populations, Manaus, Brazil

We assessed the acceptability and operational suitability of a rapid point-of-care syphilis test and identified barriers to testing among high-risk groups and healthcare professionals in a sexually transmitted infections clinic in Manaus, Brazil. Use of this test could considerably alleviate the impact of syphilis in hard-to-reach populations in the Amazon region of Brazil.