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

Syphilis in the era of re-emergence: A 6-year retrospective study from a tertiary care center in South India

Background

During the last several years, we have observed a rise in the number of patients with syphilis in our center.

Aims

To find out the trends in the presentation of syphilis to our clinic over a 6-year period and to analyze the clinicoepidemiological features of those patients.

Settings and Design

A retrospective chart review.

Subjects and Methods

We analyzed the case records of all cases of syphilis registered in our sexually transmitted infection (STI) clinic from October 1, 2012, to September 30, 2018. Syphilis was diagnosed based on clinical or serological evidence. We also evaluated these patients for any concomitant STI, including hepatitis B, hepatitis C, and HIV.

Statistical Analysis Used

The data were analyzed using SPSS software (version 20). Chi-square test was done for comparing categorical data, and P < 0.05 was considered statistically significant.

Results

During the study period, 215 patients with STI attended our clinic. Of these, 66 (31%) patients had acquired syphilis. Among them, 3 (4.5%) had primary syphilis, 23 (34.8%) had secondary syphilis, and 40 (60.6%) had latent syphilis. Fifteen (22.7%) patients had concomitant HIV infection. A statistically significant rise in the number of cases of syphilis compared with other STIs was noted in the latter half of the study period (P = 0.001). Among the 50 males with acquired syphilis, 29 (58%) were men having sex with men (MSM), including 19 bisexual persons. Among the five antenatal cases, two were detected very late in pregnancy.

Conclusions

We observed a marked increase in the number of cases of syphilis during the latter half of the study period. Primary and secondary syphilis were more frequent among MSM, suggesting a need to strengthen targeted intervention programs among them. More rigorous antenatal screening is necessary to prevent congenital syphilis.

Laboratory Evaluation of the DPP Syphilis Screen & Confirm Assay

Because syphilis is a public health concern, new strategies and tools for detecting active syphilis cases should be evaluated for future implementation. We assessed the laboratory performance of the DPP Syphilis Screen & Confirm rapid immunodiagnostic test (Chembio Diagnostics, Medford, NY, USA), using visual reading and the manufacturer's electronic test microreader, for detection of treponemal and nontreponemal antibodies in 383 fully characterized stored serum specimens. We used the Treponema pallidum particle agglutination (TPPA) test and rapid plasma reagin (RPR) test as reference tests for the DPP Syphilis Screen & Confirm assay treponemal and nontreponemal components, respectively. The sensitivity values for treponemal antibody detection by electronic reader and visual interpretation were 83.2% and 85.9%, respectively, with 100% specificity. For nontreponemal antibody detection, the sensitivity values were 65.7% and 69.0% and the specificity values were 88.7% and 89.4% for electronic reader and visual interpretation, respectively. There was excellent correlation between visual interpretation and the microreader for either component (kappa coefficient, 0.953). When restricting the analysis to RPR titers of ≥1:8, the sensitivity was 96.9% for either reading method; numerical microreader values showed good correlation with RPR titers (Spearman rho of 0.77). The DPP Syphilis Screen & Confirm assay showed good performance, compared to reference syphilis tests, using serum. Field evaluation studies should be done to validate its use for detection of active cases and for monitoring of treated syphilis patients. IMPORTANCE Syphilis remains a public health problem; therefore, health systems must incorporate screening tools that allow a rapid and accurate diagnosis to provide adequate treatment. The DPP Syphilis Screen & Confirm Assay simultaneously detects treponemal and nontreponemal antibodies, emerging as an alternative for identifying cases in situations in which there is no infrastructure to perform conventional syphilis testing, but it is necessary to generate evidence regarding the performance of this technology in various scenarios. We found that the test performs well, compared to TPPA and RPR tests, using stored samples from participants at high risk of acquiring syphilis. Additionally, when the Chembio microreader was incorporated, similar results are obtained by the device, compared to those reported by trained laboratory professionals, and correlated with the semiquantitative results of the RPR test. We think that the use of the DPP Syphilis Screen & Confirm Assay with the microreader might help in detecting active syphilis cases and perhaps in monitoring treatment responses in the field.

Characteristics of Pregnant Women with Syphilis and Factors Associated with Congenital Syphilis at a Chicago Hospital

Background

Congenital syphilis incidence has more than tripled in recent years, in parallel with the resurgence of syphilis among reproductive-aged women. An understanding of risk factors associated with maternal syphilis infection can guide prevention of congenital syphilis through prenatal diagnosis and treatment. We aimed to describe factors associated with maternal syphilis and congenital syphilis at a public medical center in Chicago, Illinois.

Methods

Maternal syphilis diagnoses were identified using a database for local health department reporting. Medical records were reviewed for infant congenital syphilis diagnoses, sociodemographic information, medical history, and other behavioral factors. Maternal characteristics associated with congenital syphilis were assessed using logistic regression.

Results

Of 106 maternal syphilis diagnoses between 2014 and 2018, 76 (72%) had a known pregnancy outcome; of these, 8 (11%) delivered an infant with congenital syphilis. Women with psychiatric illness and noninjection substance use each had a >5-fold increased odds of having an infant with congenital syphilis. Cases with congenital syphilis were more likely to have late or scant prenatal care and initiated treatment nearly 3 months later in pregnancy. None were human immunodeficiency virus positive or reported incarceration, intravenous substance use, sex work, or having sex with men who have sex with men.

Conclusions

Maternal psychiatric illness and substance use may have complicated prenatal care and delayed syphilis treatment, describing a population in need of public health intervention. Women experiencing such barriers to care may benefit from closer follow-up after a prenatal syphilis diagnosis to prevent congenital transmission.

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

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

Scaling up sexually transmissible infections point-of-care testing in remote Aboriginal and Torres Strait Islander communities: healthcare workers' perceptions of the barriers and facilitators

Background

Sexually transmissible infections (STIs), such as gonorrhoea and chlamydia, are highly prevalent, particularly in remote Aboriginal and Torres Strait Islander communities in Australia. In these settings, due to distance to centralised laboratories, the return of laboratory test results can take a week or longer, and many young people do not receive treatment, or it is considerably delayed. Point-of-care testing (POCT) provides an opportunity for same day diagnosis and treatment. Molecular POC testing for STIs was available at 31 regional or remote primary health care clinic sites through the Test-Treat-And-GO (TANGO2) program. This qualitative study sought to identify barriers and facilitators to further scaling up STI POCT in remote Aboriginal communities within Australia.

Methods

A total of 15 healthcare workers (including nurses and Aboriginal health practitioners) and five managers (including clinic coordinators and practice managers) were recruited from remote health services involved in the TTANGO2 program to participate in semi-structured in-depth interviews. Health services’ clinics were purposively selected to include those with high or low STI POCT uptake. Personnel participants were selected via a hybrid approach including nomination by clinic managers and purposive sampling to include those in roles relevant to STI testing and treatment and those who had received TTANGO2 training for POCT technology. Milat’s scaling up guide informed the coding framework and analysis.

Results

Acceptability of STI POCT technology among healthcare workers and managers was predominantly influenced by self-efficacy and perceived effectiveness of POCT technology as well as perceptions of additional workload burden associated with POCT. Barriers to integration of STI POCT included retention of trained staff to conduct POCT. Patient reach (including strategies for patient engagement) was broadly considered an enabler for STI testing scale up using POCT technology.

Conclusions

Remote healthcare clinics should be supported by both program and clinic management throughout scaling up efforts to ensure broad acceptability of STI POCT as well as addressing local health systems’ issues and identifying and enhancing opportunities for patient engagement.

Supplementary Information

The online version contains supplementary material available at 10.1186/s43058-021-00232-8.

Diagnostic tests for detecting Chlamydia trachomatis and Neisseria gonorrhoeae in rectal and pharyngeal specimens

Chlamydia trachomatis and Neisseria gonorrhoeae are two of the most often reported bacterial infections in the United States. The rectum and oropharynx are important anatomic sites of infection and can contribute to ongoing transmission. Nucleic acid amplification tests (NAATs) are the mainstays for the detection of C. trachomatis and N. gonorrhoeae infections owing to their high sensitivity and specificity. Several NAATs have been evaluated for testing in rectal and pharyngeal infections. A few assays recently received clearance by the Food and Drug Administration, including one point-of-care test. Those assays can be used for testing in symptomatic individuals, as well as for asymptomatic screening in certain patient populations. Routine screening for C. trachomatis in pharyngeal specimens is not recommended by the Centers for Disease Control and Prevention, though is often performed due to the use of multiplex assays. While expanding the types of settings for screening and using self-collected rectal and pharyngeal specimens can help to increase access and uptake of testing, additional research is needed to determine the potential benefits and costs associated with increased screening for rectal and pharyngeal C. trachomatis and N. gonorrhoeae infections on a population level.

Multiplexed technologies for sexually transmitted infections: global evidence on patient-centered and clinical health outcomes

Introduction

Conventional care packages around screening for sexually transmitted infections (STIs) entail multiple clinic visits and precipitate losses to follow-up. To prevent these losses, multiplexed technologies for STIs (immunochromatographic tests/devices/assays and molecular assays that can screen multiple pathogens or multiple strains of one STI) can yield same-day results in a single visit. Research evidence of patient-centred (preference, satisfaction) and clinical health outcomes (feasibility, case positivity, uptake, impact) has not been synthesised. We conducted a systematic review to fill this gap.

Methods

For the period 2009–2020, two independent reviewers searched PubMed and Embase, retrieved 4440 citations and abstracted data from 42 relevant studies.

Results

Of 42 studies, 10 (23.8%) evaluated multiplexed immunochromatographic and 32 (76.2%) molecular assays. Outcomes were reported as follows: preference (n=3), satisfaction (n=2), uptake (n=1), feasibility (n=2), case positivity (n=42) and impact (n=11). Screened populations included various at-risk groups. A majority (86.1%–92.4%) of participants preferred (60.2%–97.2%) multiplexed technologies (over conventional testing). Compared with conventional lab-based testing, test uptake improved by 99.4% (hepatitis C), 99.6% (Trichomonas vaginalis), 78.6% (hepatitis B) and 42.0% (HIV). Varying case positivities were documented depending on populations screened: HIV (1.8%–29.3%), hepatitis B (1.1%–23.9%), hepatitis C (0.5%–42.2%), Chlamydia trachomatis (2.8%–30.2%), Neisseria gonorrhoeae (0.0%–30.3%) and T. vaginalis (0.0%–32.7%). Regarding impact, 70.0%–100.0% of screened participants were linked to care, with result turnaround times ranging from 14 min (immunochromatographic assays) to 300 min (molecular assays).

Conclusions

Compared with conventional lab-based testing, rapid multiplexed technologies were preferred by testees and led to quicker turnaround times for many STIs yielding same-day results thereby allowing to initiate rapid linkages to care. They were further shown to be highly feasible and impactful for detection and treatment facilitation. Based on these promising results, multiplexed technologies offer potential to screen at-risk populations to reduce onward STI transmission worldwide.

Performance of Sexually Transmitted Disease Laboratories for Chlamydia trachomatis Detection in Guangdong, China

BACKGROUND

Chlamydia trachomatis detection plays a crucial role in early diagnosis and treatment of C. trachomatis infection. In the current study, the capability of sexually transmitted disease (STD) laboratories to detect C. trachomatis was investigated in Guangdong, China.

METHODS

An external quality assessment panel, including 5 positive samples with different C. trachomatis loads and 2 negative samples was distributed to 654 participating laboratories in October 2019, and the test results were analyzed by Guangdong Central STD Laboratory. The use of various C. trachomatis detection methods in Guangdong from 2015 to 2019 was also retrospectively investigated.

RESULTS

Of the 654 participating STD laboratories, 559 (85.47%) used immune chromatographic-rapid diagnostic tests (IC-RDTs) to detect C. trachomatis in 2019, and 95 (14.53%) used nucleic acid amplification tests (NAATs). The rate of NAATs use increased approximately 4-fold from 2015 to 2019. The sensitivity of IC-RDTs decreased markedly from 97.32% to 30.89% with decreasing C. trachomatis load, whereas that of NAATs was 97.62% to 100% in all positive samples. With respect to negative samples the specificity of IC-RDTs was 97.13% to 97.30% and that of NAATs was 98.95% to 100%. Laboratories using IC-RDTs were less likely to detect C. trachomatis than those using NAATs in samples with C. trachomatis loads of 20000 copies/mL or less (P < 0.0001). Further analysis indicated no significant difference (P > 0.05) in detection rate among the 4 IC-RDT assays commonly used by the participating laboratories.

CONCLUSIONS

Immune chromatographic-rapid diagnostic tests are commonly used for C. trachomatis detection by many laboratories in Guangdong, but their low sensitivity may lead to missed diagnoses. Nucleic acid amplification tests exhibit high sensitivity and specificity and should be recommended for C. trachomatis detection in STD laboratories.

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

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

Point-of-care testing for sexually transmitted infections in low-resource settings

BACKGROUND

Both the global incidence and prevalence of sexually transmitted infections continue to increase, affecting hundreds of millions of individuals, particularly in low-to middle-income countries. While a definitive diagnosis is desirable to inform STI treatment, syndromic management is the most widely used strategy in resource-limited settings. With the development of point-of-care (POC) tests, it is important to discuss how laboratories will need to adapt to new training and supervisory roles in support of testing which will largely be performed by peripheral clinical staff.

OBJECTIVES

To discuss potential applications of STI POC tests, how they could improve existing STI control strategies and the role of clinical and reference laboratories in support of initiatives to improve STI management and control activities.

SOURCES

Narrative literature review and expert opinion.

CONTENT

The paper outlines the current status of the STI epidemic worldwide and discusses the problems associated with current approaches to control these infections, particularly in low resource settings. The roles of clinical and reference laboratories will need to change in order to provide support for POC and near-patient STI testing as these technologies are introduced into clinical as well as laboratory settings.

IMPLICATIONS

Laboratories will be expected to play a leading role in the introduction and implementation of POC and near-patient STI testing. They will be required to facilitate training and provide technical and supervisory support to clinical staff on the use of these technologies to augment existing STI management and surveillance programs. In order to provide quality service, they will need to develop, introduce and maintain sustainable local QC and EQA systems. Evidence from implementation research for introduction and scale up of STI POCTs in different STI epidemic and laboratory infrastructure settings is required.

Ectopic pregnancies and endometrial microbiota

PURPOSE OF THE REVIEW

In recent years there has been significant progress in the study of endometrial microbiota. This line of investigation has not been free of controversy and discussion. It is a key for clinicians involved to remain updated with the most recent findings in microbiome and its clinical implications to be able to offer patients all possible treatments.

RECENT FINDINGS

The existence of endometrial microbiota now seems undisputed. Current lines of work are centered on dysbiosis and its connection to other pathologies. It is in the field of assisted reproductive technology where this research plays an even more crucial role. In this case, we are focusing our attention toward the study of ectopic pregnancies, searching for similarities in their etiopathogenesis and alterations in the endometrial microbiota.

SUMMARY

Ectopic pregnancy has great repercussions for patients and for the healthcare system. We must continue researching to offer patients techniques and behaviors that can prevent it. The increase in its incidence makes ectopic pregnancy an entity that we must study.

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

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