Evaluation of the utility of a rapid test for syphilis at a sexually transmitted disease clinic in Buenos Aires, Argentina

Treponema Pallidum rapid syphilis compared diagnostic algorithm syphilis in men who have sex with men (MSM)

BACKGROUND

Syphilis infection can be asymptomatic and difficult to diagnose based on clinical symptoms. Early detection and treatment are critical for preventing and controlling syphilis as well as long-term serious complications. A serological examination based on the diagnostic algorithm was used to confirm the diagnosis of syphilis. Syphilis is frequent in high-risk groups, such as men who have sex with men (MSM). Treponema pallidum (TP) rapid can be used for early syphilis detection. The diagnostic value of TP rapid with diagnostic algorithm (RPR-TPHA) utilizing whole blood in MSM should be studied.

OBJECTIVES

To determine the diagnostic value of TP rapid syphilis test compared to a diagnostic algorithm (RPR-TPHA) among MSM.

METHODS

A diagnostic test with a cross-sectional design at Dr Mohammad Hoesin Palembang General Hospital from November 2022 to January 2023. The sampling method was consecutive sampling with a total sample of 83 MSM based on inclusion and exclusion criteria. All samples were tested for RPR, TPHA, and TP rapid. The diagnostic value of TP rapid was evaluated with RPR-TPHA as a diagnostic algorithm for syphilis.

RESULTS

The sensitivity and specificity value of the TP rapid compare diagnostic algorithm as gold standard were 95.8% and 96.6% respectively. Other metrics: positive predictive value (PPV) 92%, negative predictive value (NPV) 98%, positive likelihood ratio (PLR) 28.27, negative likelihood ratio (NLR) 0.04, accuracy 96% and AUC 0.962.

CONCLUSION

The TP rapid test has a high diagnostic value and can be used to establish an early diagnosis of syphilis in MSM.

Diagnostic performance of two rapid tests for syphilis screening in people living with HIV in Cali, Colombia

INTRODUCTION

There is insufficient evidence supporting the use of rapid diagnostic tests (RDTs) for syphilis in people living with HIV (PLWH). We evaluated the diagnostic performance of two commercially available RDTs (Bioline and Determine) in PLWH in Cali, Colombia.

METHODS

A cross-sectional field validation study on consecutive adults with confirmed HIV diagnosis attending three outpatient clinics. Both RDTs were performed on capillary blood (CB), obtained by finger prick, and sera, by venipuncture. A combination of treponemal enzyme linked immunosorbent assay (ELISA) and Treponema pallidum haemagglutination assay (TPHA) on serum samples was the reference standard. Rapid plasma reagin (RPR) and clinical criteria were added to define active syphilis. Sensitivity and specificity, predictive values and likelihood ratios (LR) of RDTs were estimated with their corresponding 95% confidence interval (95% CI). Stratified analyses by sample type, patient characteristics, non-treponemal titers, operator and re-training were performed.

RESULTS

244 PLWH were enrolled, of whom 112 (46%) had positive treponemal reference tests and 26/234 (11.1%) had active syphilis. The sensitivities of Bioline on CB and sera were similar (96.4% vs 94.6%, p = 0.6). In contrast, Determine had a lower sensitivity on CB than sera (87.5% vs 99.1%, p<0.001). Sensitivities were lower in PLWH not receiving ART (Bioline 87.1% and Determine 64.5%, p<0.001) and for one of the operators (Bioline 85% and Determine 60%, p<0.001). Specificities of the RDTs were > 95% in most analyses. Predictive values were 90% or higher. For active syphilis, the RDTs showed a similar performance pattern but with decreased specificities.

CONCLUSION

The studied RDTs have an excellent performance in PLWH to screen for syphilis and potentially for active syphilis, yet Determine performs better on sera than CB. Patient characteristics and potential difficulties operators may face in acquiring enough blood volume from finger pricks should be considered for the implementation and the interpretation of RDTs.

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.

Acceptability of dual HIV/syphilis rapid test in community- and home-based testing strategy among transgender women in Buenos Aires, Argentina

BACKGROUND

Little is known of acceptability and feasibility of dual HIV and syphilis rapid tests in community- and home-based provider-initiated strategies among transgender women (TGW), in Latin America. Objectives were (1) to assess the acceptability of this strategy and, (2) to determine the percentage of positive results of HIV and syphilis, analyze the correlates of HIV or syphilis positive results, and measure the rates of effective referral and treatment completion among TGW.

METHODS

A multidisciplinary team tested 89 TGW in Buenos Aires. An acceptability survey was administered after the HIV/syphilis Duo test was used. All confirmed cases were referred for treatment initiation.

RESULTS

We found high levels of acceptability (98.8%) of this strategy among TGW. However, only 60.7% preferred simultaneous HIV and syphilis diagnosis test. Moreover, we found 9% of positive results of HIV, 51.7% of syphilis, and 3.4% of positive results for both infections. Only not being tested before was associated with an HIV positive result, and only low level of education was associated with a positive syphilis result. Among 8 TGW who tested positive for HIV, 37.5% (n = 3) started antiretroviral therapy. Of 46 who tested positive for syphilis, only 73.9% (n = 34) were effectively referred and from 23 who started treatment, only 39.1% completed it.

CONCLUSIONS

Community- and home-based dual HIV and syphilis rapid test is a feasible and highly acceptable approach for this hard-to-reach population. Implementing similar strategies could improve screening uptake and accessibility. However, these results highlight the need to improve strategies for treatment uptake, in order to reduce morbidity and risk of onward transmission.

Estimating syphilis seroprevalence among patients in a sexually transmitted infections clinic in Lilongwe, Malawi

The syndromic management of genital ulcer disease (GUD) misses asymptomatic syphilis cases but is widely utilized in limited resource settings without diagnostic capabilities, to ensure treatment for the most common etiologies of GUD. We used rapid serology tests for syphilis screening at a Malawian sexually transmitted infections clinic. The estimated seroprevalence was 9% and was highest among patients with genital ulcers (26%) and newly diagnosed HIV infection (19%). Rapid syphilis screening has the potential to increase syphilis detection, but accurate patient histories regarding syphilis diagnosis and prior treatment are needed.