The laboratory diagnosis of Syphilis

2021 ◽  
Author(s):  
Ferris Satyaputra ◽  
Stephanie Hendry ◽  
Maxwell Braddick ◽  
Pirathaban Sivabalan ◽  
Robert Norton
Keyword(s):  
Congenital Syphilis ◽  
Point Of Care ◽  
Treponema Pallidum ◽  
Laboratory Diagnosis ◽  
Nucleic Acid Amplification ◽  
Current Status ◽  
Serological Tests ◽  
Flocculation Test ◽  
The Many ◽  
Point Of Care Tests

Syphilis is a multisystem infection caused by the spirochaete Treponema pallidum. Currently, cases of possible syphilis are commonly investigated using the treponemal serological tests T. pallidum IgG chemiluminescence immunoassay (CLIA) and the T. pallidum particle agglutination (TPPA). The non-treponemal rapid plasma reagin (RPR) flocculation test is used to assess disease activity. There has been a resurgence of syphilis diagnoses in Australia. Large foci of infection have been identified in isolated communities. The remoteness of these locations, in conjunction with the particular socio-cultural characteristics of the population, pose unique challenges to the traditional diagnostic and treatment paradigms for syphilis. As a consequence of this increased incidence of syphilis, there has been interest in the utility of point of care tests (POCT), nucleic acid amplification tests (NAAT), the role of IgM testing in suspected congenital syphilis, and the laboratory investigation of possible neurosyphilis. This review looks at the current status of traditional serological assays and provides an update on more recent methods. It assesses the published literature in this area and makes recommendations for the rational use of pathology testing to aid in the diagnosis of the many facets of syphilis.

scholarly journals Microbiological Laboratory Diagnosis of Human Brucellosis: An Overview

Pathogens ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1623
Author(s):  
Giovanni Di Bonaventura ◽  
Silvia Angeletti ◽  
Andrea Ianni ◽  
Tommasangelo Petitti ◽  
Giovanni Gherardi
Keyword(s):  
Clinical Symptoms ◽  
Early Stage ◽  
Point Of Care ◽  
Laboratory Diagnosis ◽  
Cross Reactivity ◽  
Diagnostic Methods ◽  
Nucleic Acid Amplification ◽  
Human Brucellosis ◽  
Microbiological Analysis ◽  
Serological Tests

Brucella spp. are Gram-negative, non-motile, non-spore-forming, slow-growing, facultative intracellular bacteria causing brucellosis. Brucellosis is an endemic of specific geographic areas and, although underreported, represents the most common zoonotic infection, with an annual global incidence of 500,000 cases among humans. Humans represent an occasional host where the infection is mainly caused by B. melitensis, which is the most virulent; B. abortus; B. suis; and B. canis. A microbiological analysis is crucial to identifying human cases because clinical symptoms of human brucellosis are variable and aspecific. The laboratory diagnosis is based on three different microbiological approaches: (i) direct diagnosis by culture, (ii) indirect diagnosis by serological tests, and (iii) direct rapid diagnosis by molecular PCR-based methods. Despite the established experience with serological tests and highly sensitive nucleic acid amplification tests (NAATs), a culture is still considered the “gold standard” in the laboratory diagnosis of brucellosis due to its clinical and epidemiological relevance. Moreover, the automated BC systems now available have increased the sensitivity of BCs and shortened the time to detection of Brucella species. The main limitations of serological tests are the lack of common interpretative criteria, the suboptimal specificity due to interspecies cross-reactivity, and the low sensitivity during the early stage of disease. Despite that, serological tests remain the main diagnostic tool, especially in endemic areas because they are inexpensive, user friendly, and have high negative predictive value. Promising serological tests based on new synthetic antigens have been recently developed together with novel point-of-care tests without the need for dedicated equipment and expertise. NAATs are rapid tests that can help diagnose brucellosis in a few hours with high sensitivity and specificity. Nevertheless, the interpretation of NAAT-positive results requires attention because it may not necessarily indicate an active infection but rather a low bacterial inoculum, DNA from dead bacteria, or a patient that has recovered. Refined NAATs should be developed, and their performances should be compared with those of commercial and home-made molecular tests before being commercialized for the diagnosis of brucellosis. Here, we review and report the most common and updated microbiological diagnostic methods currently available for the laboratory diagnosis of brucellosis.

scholarly journals Molecular detection of Treponema pallidum sp. pallidum in blood samples of VDRL-seroreactive women with lethal pregnancy outcomes: a retrospective observational study in northern Brazil

2011 ◽  
Vol 44 (4) ◽  
pp. 451-456 ◽  
Author(s):  
Charliana Aragão Damasceno Casal ◽  
Mayra Oliveira da Silva ◽  
Igor Brasil Costa ◽  
Eliete da Cunha Araújo ◽  
Tereza Cristina de Oliveira Corvelo
Keyword(s):  
Pregnancy Outcomes ◽  
Congenital Syphilis ◽  
Treponema Pallidum ◽  
Laboratory Diagnosis ◽  
Control Measures ◽  
Prenatal Period ◽  
Serum Samples ◽  
Significant Difference ◽  
Northern Brazil ◽  
Maternal Syphilis

INTRODUCTION: Although control measures of maternal and congenital syphilis are available in Brazil, difficulties exist within the healthcare network in providing a laboratory diagnosis of the infection during the prenatal period. The objective of this study was to confirm the presence of Treponema pallidum by PCR in women with positive VDRL serology and lethal pregnancy outcomes, i.e., abortion, stillbirth and neonatal death. METHODS: A retrospective study was conducted on VDRLseroreactive women with lethal pregnancy outcomes admitted to the Fundação Santa Casa de Misericórdia do Pará (FSCM-PA) between January and July 2004. Serum samples and DNA from whole blood were obtained at the time of screening by the VDRL test. These samples were analyzed by IgG ELISA, IgM FTA-Abs and simple PCR (polA). RESULTS: During the study period, 0.7% (36/4,912) of women with lethal pregnancy outcomes presented a positive VDRL test. The polAgene was amplified in 72.7% (24/33) of these women, with 55.6% (20/36) and 94.4% (34/36) presenting IgM and IgG antibodies against T. pallidum, respectively. Comparison of these results showed a significant difference, with agreement between the PCR and IgM FTA-Abs results, suggesting that maternal syphilis was an active infection. No basic cause of death of the conceptus was reported in 97.2% (35/36) of cases. Among women who were submitted to the VDRL test during the prenatal period, only four of the nine seroreactive patients underwent treatment. CONCLUSIONS: The high frequency of syphilis in the group studied indicates the fragility of the service of infection diagnosis, treatment and monitoring, compromising epidemiological control.

scholarly journals Are Treponema pallidum Specific Rapid and Point-of-Care Tests for Syphilis Accurate Enough for Screening in Resource Limited Settings? Evidence from a Meta-Analysis

PLoS ONE ◽  
2013 ◽  
Vol 8 (2) ◽  
pp. e54695 ◽  
Author(s):  
Yalda Jafari ◽  
Rosanna W. Peeling ◽  
Sushmita Shivkumar ◽  
Christiane Claessens ◽  
Lawrence Joseph ◽  
...  
Keyword(s):  
Point Of Care ◽  
Meta Analysis ◽  
Treponema Pallidum ◽  
Resource Limited Settings ◽  
Resource Limited ◽  
Point Of Care Tests

scholarly journals Point-of-Care Diagnostic Tools for Surveillance of SARS-CoV-2 Infections

2021 ◽  
Vol 9 ◽  
Author(s):  
Dhanasekaran Sakthivel ◽  
David Delgado-Diaz ◽  
Laura McArthur ◽  
William Hopper ◽  
Jack S. Richards ◽  
...  
Keyword(s):  
Large Scale ◽  
Clinical Symptoms ◽  
Point Of Care ◽  
Cost Effective ◽  
Nucleic Acid Amplification ◽  
Diagnostic Tools ◽  
Rt Pcr ◽  
Serological Tests ◽  
Polymerase Chain ◽  
Effective Public Health

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a recently emerged and highly contagious virus that causes coronavirus disease 2019 (COVID-19). As of August 24, 2021, there were more than 212 million confirmed COVID-19 cases and nearly 4.4 million deaths reported globally. Early diagnosis and isolation of infected individuals remains one of the most effective public health interventions to control SARS-CoV-2 spread and for effective clinical management of COVID-19 cases. Currently, SARS-CoV-2 infection is diagnosed presumptively based on clinical symptoms and confirmed by detecting the viral RNA in respiratory samples using reverse transcription polymerase chain reaction (RT-PCR). Standard RT-PCR protocols are time consuming, expensive, and technically demanding, which makes them a poor choice for large scale and point-of-care screening in resource-poor settings. Recently developed isothermal nucleic acid amplification tests (iNAAT), antigen and/or serological tests are cost-effective to scale COVID-19 testing at the point-of-care (PoC) and for surveillance activities. This review discusses the development of rapid PoC molecular tools for the detection and surveillance of SARS-CoV-2 infections.

RECENT DEVELOPMENTS IN LABORATORY DIAGNOSIS OF COVID-19 INFECTION- AN UPDATE

2021 ◽  
pp. 58-60
Author(s):  
Ivneet Kour ◽  
Lipika Singhal ◽  
Varsha Gupta
Keyword(s):  
Point Of Care ◽  
Laboratory Diagnosis ◽  
Public Health Emergency ◽  
World Health ◽  
Global Public Health ◽  
Rt Pcr ◽  
Testing Strategies ◽  
Recent Developments ◽  
Health Organization ◽  
Point Of Care Tests

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This new virus and disease were unknown before the outbreak began in Wuhan, Hubei Province of China, in December 2019. The World Health Organization (WHO) initially declared COVID19 as the global public health emergency on 30th January 2020 and subsequently a pandemic on March 11, 2020. Besides availability of RT-PCR there is need for development of rapid point of care tests with better sensitivity and specicity which helps in early and accurate diagnosis and also aids in containing the spread . This review summarizes various molecular diagnostics methods, technical guidelines, and advanced testing strategies adopted in India for laboratory diagnosis of COVID-19.

Investigations and microscopy

2019 ◽  
pp. 63-80
Keyword(s):  
Nucleic Acid ◽  
Laboratory Testing ◽  
Trichomonas Vaginalis ◽  
Point Of Care ◽  
Rapid Test ◽  
The Other ◽  
Nucleic Acid Amplification ◽  
Blood Samples ◽  
Dark Ground ◽  
Point Of Care Tests

This chapter covers investigations and tests commonly used in sexual health. Some investigations can be performed on-site as the patient waits, such as urinalysis, pregnancy tests, and increasingly available point of care tests for infections such as HIV and, less commonly, the other blood-borne viruses, syphilis, Trichomonas vaginalis. On-site microscopy helps with diagnosis of genital candidiasis, bacterial vaginosis, N. gonorrhoeae infection, and T. vaginalis. Other investigations require sending samples away for laboratory testing of genital or ulcer swab, urine, or blood samples for STI and blood-borne viruses. This chapter explains the use of light and dark ground microscopy, near patient rapid test technologies, molecular methods such as nucleic acid amplification, culture and serology. Sensitivities and specificities of commonly available test kits are included.

scholarly journals An Update on Advances in COVID-19 Laboratory Diagnosis and Testing Guidelines in India

2021 ◽  
Vol 9 ◽  
Author(s):  
K. S. Rajesh Kumar ◽  
Suhail Sayeed Mufti ◽  
Vinu Sarathy ◽  
Diganta Hazarika ◽  
Radheshyam Naik
Keyword(s):  
Large Scale ◽  
Vaccine Development ◽  
Point Of Care ◽  
Diagnostic Testing ◽  
Public Health Intervention ◽  
Laboratory Diagnosis ◽  
Accurate Diagnosis ◽  
Nucleic Acid Amplification ◽  
Rt Pcr ◽  
Outbreak Management

The declaration of COVID-19 as a global pandemic has warranted the urgent need for technologies and tools to be deployed for confirming diagnosis of suspected cases. Diagnostic testing for COVID-19 is critical for understanding epidemiology, contract-tracing, case management, and to repress the transmission of the SARS-CoV-2. Currently, the Nucleic Acid Amplification Test (NAAT)-based RT-PCR technique is a gold standard test used for routine diagnosis of COVID-19 infection. While there are many commercially available RT-PCR assay kits available in the market, selection of highly sensitive, specific, and validated assays is most crucial for the accurate diagnosis of COVID-19 infection. Laboratory diagnosis of SARS-CoV-2 is extremely important in the disease and outbreak management. Development of rapid point of care tests with better sensitivity and specificity is the critical need of the hour as this will help accurate diagnosis and aid in containing the spread of SARS-CoV-2 infection. Early detection of viral infection greatly enhances implementation of specific public health intervention, such as infection control, environmental decontamination, and the closure of specific high-risk zones. Large-scale sequencing of SARS-CoV-2 genome isolated from affected populations across the world needs to be carried to monitor mutations that might affect performance of molecular tests. Creation of genome repositories and open-source genetic databases for use by global researchers is clearly the way forward to manage COVID-19 outbreak and accelerate vaccine development. This review summarizes various molecular diagnostics methods, technical guidelines, and advanced testing strategies adopted in India for laboratory diagnosis of COVID-19.

scholarly journals Use of rapid point-of-care diagnostic tests for the elimination of congenital syphilis: what is the evidence?

2018 ◽  
Vol 33 (5) ◽  
Author(s):  
Ranmini Kularatne
Keyword(s):  
Congenital Syphilis ◽  
Point Of Care ◽  
Public Health Problem ◽  
World Health Organisation ◽  
Clinic Visit ◽  
World Health ◽  
Technical Specifications ◽  
Adverse Pregnancy ◽  
Maternal Syphilis ◽  
Point Of Care Tests

Congenital syphilis constitutes a major preventable public health problem, that has been targeted for elimination by the World Health Organisation. Adverse pregnancy outcomes occur in upto 80% of untreated maternal syphilis. National impact targets for elimination include 95% syphilis testing and treatment coverage for pregnant women. Screening and treatment of maternal syphilis should ideally happen at the first ante-natal clinic visit. This may be facilitated by the use of rapid point-of-care tests (POCTs), especially for healthcare centres with limited laboratory access. There are several commercial syphilis POCTs, some of which also screen for HIV infection. These have different technical specifications, and their performance characteristics vary when capillary fingerprick whole blood is used for testing in a clinic setting. Syphilis POCT implementation in ante-natal care is affordable and rational in resource-constrained settings; however, managers and policy makers should be aware of the various programmatic issues that need to be addressed in the preimplementation phase and monitored over time.

scholarly journals Advances in Directly Amplifying Nucleic Acids from Complex Samples

Biosensors ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 117 ◽  
Author(s):  
Faye M. Walker ◽  
Kuangwen Hsieh
Keyword(s):  
Nucleic Acid ◽  
Sample Preparation ◽  
Point Of Care ◽  
Nucleic Acid Amplification ◽  
Current Status ◽  
Diagnostic Tools ◽  
Complex Samples ◽  
Lab On Chip ◽  
On Chip ◽  
Effective Visualization

Advances in nucleic acid amplification technologies have revolutionized diagnostics for systemic, inherited, and infectious diseases. Current assays and platforms, however, often require lengthy experimental procedures and multiple instruments to remove contaminants and inhibitors from clinically-relevant, complex samples. This requirement of sample preparation has been a bottleneck for using nucleic acid amplification tests (NAATs) at the point of care (POC), though advances in “lab-on-chip” platforms that integrate sample preparation and NAATs have made great strides in this space. Alternatively, direct NAATs—techniques that minimize or even bypass sample preparation—present promising strategies for developing POC diagnostic tools for analyzing real-world samples. In this review, we discuss the current status of direct NAATs. Specifically, we surveyed potential testing systems published from 1989 to 2017, and analyzed their performances in terms of robustness, sensitivity, clinical relevance, and suitability for POC diagnostics. We introduce bubble plots to facilitate our analysis, as bubble plots enable effective visualization of the performances of these direct NAATs. Through our review, we hope to initiate an in-depth examination of direct NAATs and their potential for realizing POC diagnostics, and ultimately transformative technologies that can further enhance healthcare.

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