scholarly journals Canadian Public Health Laboratory Network Laboratory Guidelines for the Use of Direct Tests to Detect Syphilis in Canada

2015 ◽  
Vol 26 (supplement a) ◽  
pp. 13A-17A ◽  
Author(s):  
Raymond SW Tsang ◽  
Muhammad Morshed ◽  
Max A Chernesky ◽  
Gayatri C Jayaraman ◽  
Kamran Kadkhoda
Keyword(s):  
Ethical Issues ◽  
Direct Detection ◽  
Histopathological Examination ◽  
Fluorescent Antibody ◽  
Treponema Pallidum ◽  
Antibody Test ◽  
Turnaround Time ◽  
Dark Field ◽  
Specimen Collection ◽  
Infectivity Test

Treponema pallidumsubsp.pallidumand/or its nucleic acid can be detected by various methods such as microscopy, rabbit infectivity test or polymerase chain reaction (PCR) tests. The rabbit infectivity test forT. pallidum, although very sensitive, has been discontinued from most laboratories due to ethical issues related to the need for animal inoculation with liveT. pallidum, the technically demanding procedure and long turnaround time for results, thus making it impractical for routine diagnostic use. Dark-field and phase-contrast microscopy are still useful at clinic- or hospital-based laboratories for near-bedside detection ofT. pallidumin genital, skin or mucous lesions although their availability is decreasing. The lack of reliable and specific anti-T. pallidumantibodies and its inferior sensitivity to PCR may explain why the direct fluorescent antibody test forT. pallidumis not widely available for clinical use. Immunohistochemical staining forT. pallidumalso depends on the availability of specific antibodies, and the method is only applicable for histopathological examination of biopsy and autopsy specimens necessitating an invasive specimen collection approach. With recent advances in molecular diagnostics, PCR is considered to be the most reliable, versatile and practical for laboratories to implement. In addition to being an objective and sensitive test for direct detection ofTreponema pallidumsubsp. pallidumDNA in skin and mucous membrane lesions, the resulting PCR amplicons from selected gene targets can be further characterized for antimicrobial (macrolide) susceptibility testing, strain typing and identification ofT. pallidumsubspecies.

Laboratory diagnosis and interpretation of tests for syphilis.

1995 ◽  
Vol 8 (1) ◽  
pp. 1-21 ◽  
Author(s):  
S A Larsen ◽  
B M Steiner ◽  
A H Rudolph
Keyword(s):  
Congenital Syphilis ◽  
Direct Detection ◽  
Venereal Disease ◽  
Treponema Pallidum ◽  
Clinical Signs ◽  
Laboratory Diagnosis ◽  
Dark Field ◽  
Alternative Methods ◽  
Detection Methods ◽  
Enzyme Linked Immunosorbent Assay

The lack of a method for demonstrating the presence of Treponema pallidum by growth necessitates the use of alternative methods. Traditionally, these methods are divided into direct detection methods (animal inoculation, dark-field microscopy, etc.) and serologic tests for the presence of patient antibody against T. pallidum. Serologic methods are further divided into two classes. One class, the nontreponemal tests, detects antibodies to lipoidal antigens present in either the host or T. pallidum; examples are the Venereal Disease Research Laboratory and rapid plasma reagin and tests. Reactivity in these tests generally indicates host tissue damage that may not be specific for syphilis. Because these tests are easy and inexpensive to perform, they are commonly used for screening, and with proper clinical signs they are suggestive of syphilis. The other class of test, the treponemal tests, uses specific treponemal antigens. Confirmation of infection requires a reactive treponemal test. Examples of the treponemal tests are the microhemagglutination assay for antibodies to T. pallidum and the fluorescent treponemal antibody absorption test. These tests are more expensive and complicated to perform than the nontreponemal tests. On the horizon are a number of direct antigen, enzyme-linked immunosorbent assay, and PCR techniques. Several of these techniques have shown promise in clinical trials for the diagnosis of congenital syphilis and neurosyphilis that are presently difficult to diagnose.

scholarly journals Molecular and Direct Detection Tests for Treponema pallidum Subspecies pallidum: A Review of the Literature, 1964–2017

2020 ◽  
Vol 71 (Supplement_1) ◽  
pp. S4-S12 ◽  
Author(s):  
Elitza S Theel ◽  
Samantha S Katz ◽  
Allan Pillay
Keyword(s):  
Direct Detection ◽  
Treponema Pallidum ◽  
Dark Field ◽  
Performance Characteristics ◽  
Nucleic Acid Amplification ◽  
Detection Methods ◽  
Cochrane Library ◽  
Silver Stain ◽  
Detection Techniques ◽  
Ovid Medline

Abstract Direct detection methods for Treponema pallidum include dark-field microscopy (DFM), direct fluorescence antibody (DFA) testing, immunohistochemistry (IHC), and nucleic acid amplification tests (NAATs). Here, we reviewed the relevant syphilis diagnostic literature to address 2 main questions with respect to T. pallidum direct detection techniques: “What are the performance characteristics for each direct detection test for T. pallidum and what are the optimal specimen types for each test?” and “What options are available for T. pallidum molecular epidemiology?” To answer these questions, we searched 5 electronic databases (OVID Medline, OVID Embase, CINAHL, Cochrane Library, and Scopus) from 1964 to 2017 using relevant search terms and identified 1928 articles, of which 37 met our inclusion criteria. DFM and DFA sensitivities ranged from 73% to 100% in cases of primary syphilis; and while sensitivity using silver stain histopathology for T. pallidum was generally low (0%–41%), higher performance characteristics were observed for T. pallidum–specific IHC (49–92%). Different genes have been targeted by T. pallidum–specific NAATs, with the majority of studies indicating that sensitivity is primarily dependent on the type of collected biological sample, with highest sensitivity observed in primary lesion exudate (75–95%). Given the rising incidence of syphilis, the development of direct, Food and Drug Administration–cleared T. pallidum NAATs should be considered an immediate priority.

scholarly journals Recent trends in smartphone-based detection for biomedical applications: a review

2021 ◽  
Vol 413 (9) ◽  
pp. 2389-2406 ◽  
Author(s):  
Soumyabrata Banik ◽  
Sindhoora Kaniyala Melanthota ◽  
Arbaaz ◽  
Joel Markus Vaz ◽  
Vishak Madhwaraj Kadambalithaya ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Histopathological Examination ◽  
Dark Field ◽  
Portable Devices ◽  
Food Technology ◽  
Wide Range ◽  
Technological Interventions ◽  
Recent Trends ◽  
Increasing Demand

AbstractSmartphone-based imaging devices (SIDs) have shown to be versatile and have a wide range of biomedical applications. With the increasing demand for high-quality medical services, technological interventions such as portable devices that can be used in remote and resource-less conditions and have an impact on quantity and quality of care. Additionally, smartphone-based devices have shown their application in the field of teleimaging, food technology, education, etc. Depending on the application and imaging capability required, the optical arrangement of the SID varies which enables them to be used in multiple setups like bright-field, fluorescence, dark-field, and multiple arrays with certain changes in their optics and illumination. This comprehensive review discusses the numerous applications and development of SIDs towards histopathological examination, detection of bacteria and viruses, food technology, and routine diagnosis. Smartphone-based devices are complemented with deep learning methods to further increase the efficiency of the devices.

scholarly journals Occurrence of antibodies against Neospora caninum and/or Toxoplasma gondii in dogs with neurological signs

2011 ◽  
Vol 20 (3) ◽  
pp. 202-206 ◽  
Author(s):  
Nicolle Fridlund Plugge ◽  
Fabiano Montiani Ferreira ◽  
Rosária Regina Tesoni de Barros Richartz ◽  
Adriana de Siqueira ◽  
Rosangela Locatelli Dittrich
Keyword(s):  
Toxoplasma Gondii ◽  
Neospora Caninum ◽  
Neurological Diseases ◽  
Fluorescent Antibody ◽  
Antibody Test ◽  
Metropolitan Region ◽  
Serological Tests ◽  
Stray Dogs ◽  
Neurological Signs ◽  
Significant Difference

This study aimed to evaluate occurrences of antibodies against Neospora caninum and Toxoplasma gondii in dogs with neurological signs. Blood samples from 147 dogs were collected: 127 from owned dogs (attended at the Veterinary Teaching Hospital of the Federal University of Paraná (HV-UFPR) and at private veterinary clinics in the city of Curitiba), and 20 from stray dogs found in Curitiba's metropolitan region. The dogs presented one or more of the following neurological signs: seizures, paresis or paralysis, ataxia, behavioral abnormalities, sensory and somatic disorders and chorioretinitis. The samples were analyzed by means of the indirect fluorescent antibody test (IFAT), at a cutoff dilution of 1:50. Out of the 147 samples obtained, 17 (11.56%) were seropositive for N. caninum, 31 (21.08%) for T. gondii and four (2.72%) for both protozoa. Serum titration on the positive animals showed that 54.83% (17/31) and 41.18% (7/17) had titers > 1:200 against T. gondii and N. caninum, respectively. A significant difference in seropositivity for T. gondii (P = 0.021; OR = 2.87; CI = 1.1 > 2.8 > 7.4) was observed between owned dogs (18.11%) and stray dogs (40%). Inclusion of serological tests for neosporosis and toxoplasmosis is recommended in diagnosing neurological diseases in dogs.

Investigation of Anti-Toxoplasma gondii Antibodies in Cats of the Ankara Region of Turkey Using the Sabin-Feldman Dye Test and an Indirect Fluorescent Antibody Test

2008 ◽  
Vol 94 (4) ◽  
pp. 817-820 ◽  
Author(s):  
Ayşegül Taylan Özkan ◽  
Bekir Çelebi ◽  
Cahit Babür ◽  
Araceli Lucio-Forster ◽  
Dwight D. Bowman ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Indirect Fluorescent Antibody Test ◽  
Fluorescent Antibody ◽  
Antibody Test ◽  
Indirect Fluorescent Antibody
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