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Bharti S, Sharma P. The Aftermath of Widal Positivity on the Diagnosis of Tuberculosis and Fluoroquinolone Resistance in India. EMJ MICROBIOLOGY & INFECTIOUS DISEASES 2023. [DOI: 10.33590/emjmicrobiolinfectdis/10306500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Affiliation(s)
| | - Priya Sharma
- Department of Pulmonary Medicine, All India Institute of Medical Sciences (AIIMS) Patna, India
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Sharma T, Sharma C, Sankhyan A, Bedi SP, Bhatnagar S, Khanna N, Gautam V, Sethi S, Vrati S, Tiwari A. Serodiagnostic evaluation of recombinant CdtB of S. Typhi as a potential candidate for acute typhoid. Immunol Res 2019; 66:503-512. [PMID: 29931558 DOI: 10.1007/s12026-018-9009-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Typhoid fever caused by human restricted Salmonella typhi presents a considerable health burden on developing South-Asian nations like India. The suboptimal sensitivity and specificity associated with culture-based isolation of etiological agent and the extensively used surface antigen-based serological assays often lead to misdiagnosis and inappropriate antimicrobial treatment. The increasing reports of the emergence of resistant strains and undefined disease burden signify the critical need for an inexpensive, reliable, easy-to-use, and highly sensitive diagnostic test for typhoid fever. Utilizing S. typhi-specific and immunogenic antigens in sero-diagnostic assays could lead to precise diagnosis of acute typhoid and prompt treatment. In this study, we report cloning, expression, and purification of recombinant Cytolethal distending toxin subunit B (CdtB) of S. typhi, which is reported to be highly specific, immunogenic, and expressed only upon S. typhi infection. We further evaluated the purified recombinant CdtB for its diagnostic potential in an IgM-based indirect ELISA format using 33 human samples. Twenty-one serum samples from blood culture confirmed cases (n = 21) of typhoid and 12 samples from healthy controls (n = 12) were tested. The assay showed sensitivity of 100% and specificity of 83.3% respectively with positive and negative predictive values of 91.3 and 100% respectively. Efficient detection of specific IgM antibodies indicates that CdtB could be highly valuable in sero-diagnosis of acute typhoid and rapid screening of clinical samples.
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Affiliation(s)
- Tarang Sharma
- Centre for Bio-design & Diagnostics, Translational Health Science and Technology Institute, Faridabad, Haryana, India
| | - Chandresh Sharma
- Centre for Bio-design & Diagnostics, Translational Health Science and Technology Institute, Faridabad, Haryana, India
| | - Anurag Sankhyan
- Centre for Bio-design & Diagnostics, Translational Health Science and Technology Institute, Faridabad, Haryana, India.,Central Research Institute, Kasauli, Himachal Pradesh, India
| | - Sanjiv Pal Bedi
- Department of Experimental Medicine & Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Shinjini Bhatnagar
- Paediatric Biology Centre, Translational Health Science and Technology Institute, Faridabad, Haryana, India
| | - Navin Khanna
- International Centre for Genetic Engineering & Biotechnology, New Delhi, India
| | - Vikas Gautam
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Sunil Sethi
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Sudhanshu Vrati
- Regional Centre for Biotechnology, Faridabad, Haryana, India
| | - Ashutosh Tiwari
- Centre for Bio-design & Diagnostics, Translational Health Science and Technology Institute, Faridabad, Haryana, India. .,Department of Experimental Medicine & Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
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Storey HL, Huang Y, Crudder C, Golden A, de los Santos T, Hawkins K. A Meta-Analysis of Typhoid Diagnostic Accuracy Studies: A Recommendation to Adopt a Standardized Composite Reference. PLoS One 2015; 10:e0142364. [PMID: 26566275 PMCID: PMC4643909 DOI: 10.1371/journal.pone.0142364] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 10/21/2015] [Indexed: 01/09/2023] Open
Abstract
Novel typhoid diagnostics currently under development have the potential to improve clinical care, surveillance, and the disease burden estimates that support vaccine introduction. Blood culture is most often used as the reference method to evaluate the accuracy of new typhoid tests; however, it is recognized to be an imperfect gold standard. If no single gold standard test exists, use of a composite reference standard (CRS) can improve estimation of diagnostic accuracy. Numerous studies have used a CRS to evaluate new typhoid diagnostics; however, there is no consensus on an appropriate CRS. In order to evaluate existing tests for use as a reference test or inclusion in a CRS, we performed a systematic review of the typhoid literature to include all index/reference test combinations observed. We described the landscape of comparisons performed, showed results of a meta-analysis on the accuracy of the more common combinations, and evaluated sources of variability based on study quality. This wide-ranging meta-analysis suggests that no single test has sufficiently good performance but some existing diagnostics may be useful as part of a CRS. Additionally, based on findings from the meta-analysis and a constructed numerical example demonstrating the use of CRS, we proposed necessary criteria and potential components of a typhoid CRS to guide future recommendations. Agreement and adoption by all investigators of a standardized CRS is requisite, and would improve comparison of new diagnostics across independent studies, leading to the identification of a better reference test and improved confidence in prevalence estimates.
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Affiliation(s)
- Helen L. Storey
- Diagnostics Program, PATH, Seattle, Washington, United States of America
- * E-mail:
| | - Ying Huang
- Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Chris Crudder
- Diagnostics Program, PATH, Seattle, Washington, United States of America
| | - Allison Golden
- Diagnostics Program, PATH, Seattle, Washington, United States of America
| | - Tala de los Santos
- Diagnostics Program, PATH, Seattle, Washington, United States of America
| | - Kenneth Hawkins
- Diagnostics Program, PATH, Seattle, Washington, United States of America
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Beig FK, Ahmad F, Ekram M, Shukla I. Typhidot M and Diazo test vis-à-vis blood culture and Widal test in the early diagnosis of typhoid fever in children in a resource poor setting. Braz J Infect Dis 2011; 14:589-93. [PMID: 21340299 DOI: 10.1016/s1413-8670(10)70116-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Accepted: 09/01/2010] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVE Typhoid fever is a major public health problem. A test which is simple, reliable and can be carried out in small laboratories is the need of the hour. We prospectively evaluated typhidot M and Diazo tests vis-à-vis blood culture and Widal test in children. METHODS Patients aged 6 months to 12 years, having fever of more than four days duration with clinical suspicion of typhoid fever were enrolled. Patients in whom other diagnosis was made served as control. The tests under scrutiny were validated against blood culture and then all the four tests were evaluated among patients who presented in the first week of illness. RESULTS Blood culture was positive in only 27.3% of the cases. Among these culture positive cases, typhidot M test had the highest sensitivity, specificity, PPV and NPV of 90% (95% CI = 74.4-96.5), 100% (95% CI = 90.1-100), 100% (95% CI = 87.5-100), and 92.1% (95% CI = 79.2-97.3) respectively. Diazo test ranked next with sensitivity, specificity, PPV and NPV of 86.7% (95% CI = 70.3-94.7), 85.7% (95% CI = 70.6-93.7), 83.9% (95% CI = 67.4-92.9), 88.2% (95% CI = 73.4-95.3) respectively. Among clinically suspected typhoid cases, the overall sensitivity, of blood culture, Widal, typhidot M, Diazo was 27.3% (95% CI = 19.8- 36.3), 64.6% (95% CI = 55.3-72.9), 89.1% (95% CI = 81.9-93.7), 80.9% (95% CI = 72.6-87.2) respectively. In the first week of illness, typhidot M showed the best sensitivity [86.2% (95% CI = 69.4-94.5)] followed by Diazo [79% (95% CI = 61.6-90.2)], Widal [41.4% (95% CI = 25.5-59.3)] and blood culture [31% (95% CI = 17.3-49.2)]. CONCLUSION Both Typhidot M and Diazo are good screening tests for the diagnosis of typhoid fever. Typhidot M is superior to Diazo but the latter is more suitable to resource poor settings being economic and easy to perform.
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Affiliation(s)
- Farzana K Beig
- Department of Pediatrics, JN Medical College, Aligarh Muslim University, India.
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Chart H, Cheasty T, de Pinna E, Siorvanes L, Wain J, Alam D, Nizami Q, Bhutta Z, Threlfall EJ. Serodiagnosis of Salmonella enterica serovar Typhi and S. enterica serovars Paratyphi A, B and C human infections. J Med Microbiol 2007; 56:1161-1166. [PMID: 17761477 DOI: 10.1099/jmm.0.47197-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The aim of this study was to evaluate an immunoassay for the detection of human serum antibodies to the LPS and flagellar antigens of Salmonella Typhi and Salmonella Paratyphi A, B and C, and to the Vi capsular polysaccharide of S. Typhi and S. Paratyphi C. A total of 330 sera were used; these originated from 15 patients who were culture-positive for S. Typhi and 15 healthy controls, together with 300 sera submitted to the Laboratory of Enteric Pathogens for Salmonella serodiagnosis. By SDS-PAGE/immunoblotting, all 15 sera from culture-positive patients had serum antibodies to the 9,12 LPS antigens and 10 had antibodies to the ‘d’ flagellar antigens. Of the 300 reference sera, 22 had antibodies to the 9,12 LPS antigens, one to the 1,4,5,12 LPS antigens and 12 to the 6,7 LPS antigens. Only two sera had antibodies to flagellar antigens, one of which bound to the ‘b’ and the other to the ‘d’ antigen. An ELISA was developed that successfully detected serum antibodies to the Vi capsular polysaccharides, but because of the kinetics of serum antibody production to the Vi, these antibodies may be of limited value in the serodiagnosis of acute infection with S. Typhi and S. Paratyphi C. The immunoassays described here provide a sensitive means of detecting serum antibodies to the LPS, flagellar and Vi antigens of S. Typhi and S. Paratyphi, and constitute a viable replacement for the Widal assay for the screening of sera. The Salmonella serodiagnosis protocols described here are the new standard operating procedures used by the Health Protection Agency's National Salmonella Reference Centre based in the Laboratory of Enteric Pathogens, Colindale, UK.
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Affiliation(s)
- Henrik Chart
- Laboratory of Enteric Pathogens, Department of Gastrointestinal Infections, Centre for Infections, Health Protection Agency, 61 Colindale Avenue, London NW9 5EQ, UK
| | - Thomas Cheasty
- Laboratory of Enteric Pathogens, Department of Gastrointestinal Infections, Centre for Infections, Health Protection Agency, 61 Colindale Avenue, London NW9 5EQ, UK
| | - Elizabeth de Pinna
- Laboratory of Enteric Pathogens, Department of Gastrointestinal Infections, Centre for Infections, Health Protection Agency, 61 Colindale Avenue, London NW9 5EQ, UK
| | - Lisa Siorvanes
- Laboratory of Enteric Pathogens, Department of Gastrointestinal Infections, Centre for Infections, Health Protection Agency, 61 Colindale Avenue, London NW9 5EQ, UK
| | - John Wain
- The Wellcome Trust Sanger Institute Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - Didar Alam
- Department of Paediatrics and Child Health, The Aga Khan University Medical Centre, PO Box 3500, Karachi, Pakistan
| | - Qamarauddin Nizami
- Department of Paediatrics and Child Health, The Aga Khan University Medical Centre, PO Box 3500, Karachi, Pakistan
| | - Zulfiqar Bhutta
- Department of Paediatrics and Child Health, The Aga Khan University Medical Centre, PO Box 3500, Karachi, Pakistan
| | - E John Threlfall
- Laboratory of Enteric Pathogens, Department of Gastrointestinal Infections, Centre for Infections, Health Protection Agency, 61 Colindale Avenue, London NW9 5EQ, UK
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Willke A, Ergonul O, Bayar B. Widal test in diagnosis of typhoid fever in Turkey. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 2002; 9:938-41. [PMID: 12093703 PMCID: PMC120044 DOI: 10.1128/cdli.9.4.938-941.2002] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We studied the value of the Widal tube agglutination test for the diagnosis of typhoid fever. The subjects were all adults >18 years of age and were divided into four groups: (i) 317 healthy blood donor controls, (ii) 31 bacteriologically confirmed patients with Salmonella enterica serotype Typhi, (iii) 21 patients with a clinical diagnosis of typhoid fever, and (iv) 41 febrile nontyphoid patients. Blood donor controls were screened with a slide agglutination test for the Salmonella enterica serotype Typhi O and H antigens, and positives were then tested with the Widal test. Acute- and convalescent-phase sera from patients in groups 2, 3, and 4 were obtained 7 to 10 days apart and tested by the Widal test. Using a cutoff of >or = 1/200 for the O antigen test performed on acute-phase serum gave a sensitivity of 52% and a specificity of 88% with a positive predictive value (PPV) of 76% and a negative predictive value (NPV) of 71%. This increased to 90% sensitivity and specificity with a PPV of 88% and an NPV of 93% when the convalescent-phase serum was tested. We concluded that O and H agglutinin titers of > or = 1/200 are of diagnostic significance. The Widal test is easy, inexpensive, and relatively noninvasive. It can be of diagnostic value when blood cultures are not available or practical. The results must be interpreted cautiously because of the low sensitivity of the test. The Widal test done on convalescent-phase serum gave more-reliable results with higher specificity and sensitivity.
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Affiliation(s)
- Ayse Willke
- Kocaeli Universitesi Tip Fakultesi Klinik Bakteriyoloji ve Infeksiyon Hastaliklari AD, Izmit, Turkey.
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House D, Wain J, Ho VA, Diep TS, Chinh NT, Bay PV, Vinh H, Duc M, Parry CM, Dougan G, White NJ, Hien TT, Farrar JJ. Serology of typhoid fever in an area of endemicity and its relevance to diagnosis. J Clin Microbiol 2001; 39:1002-7. [PMID: 11230418 PMCID: PMC87864 DOI: 10.1128/jcm.39.3.1002-1007.2001] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Currently, the laboratory diagnosis of typhoid fever is dependent upon either the isolation of Salmonella enterica subsp. enterica serotype Typhi from a clinical sample or the detection of raised titers of agglutinating serum antibodies against the lipopolysaccharide (LPS) (O) or flagellum (H) antigens of serotype Typhi (the Widal test). In this study, the serum antibody responses to the LPS and flagellum antigens of serotype Typhi were investigated with individuals from a region of Vietnam in which typhoid is endemic, and their usefulness for the diagnosis of typhoid fever was evaluated. The antibody responses to both antigens were highly variable among individuals infected with serotype Typhi, and elevated antibody titers were also detected in a high proportion of serum samples from healthy subjects from the community. In-house enzyme-linked immunosorbent assays (ELISAs) for the detection of specific classes of anti-LPS and antiflagellum antibodies were compared with other serologically based tests for the diagnosis of typhoid fever (Widal TO and TH, anti-serotype Typhi immunoglobulin M [IgM] dipstick, and IDeaL TUBEX). At a specificity of > or =0.93, the sensitivities of the different tests were 0.75, 0.55, and 0.52 for the anti-LPS IgM, IgG, and IgA ELISAs, respectively; 0.28 for the antiflagellum IgG ELISA; 0.47 and 0.32 for the Widal TO and TH tests, respectively; and 0.77 for the anti-serotype Typhi IgM dipstick assay. The specificity of the IDeaL TUBEX was below 0.90 (sensitivity, 0.87; specificity, 0.76). The serological assays based on the detection of IgM antibodies against either serotype Typhi LPS (ELISA) or whole bacteria (dipstick) had a significantly higher sensitivity than the Widal TO test when used with a single acute-phase serum sample (P < or = 0.007). These tests could be of use for the diagnosis of typhoid fever in patients who have clinical typhoid fever but are culture negative or in regions where bacterial culturing facilities are not available.
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Affiliation(s)
- D House
- Department of Biochemistry, Imperial College of Science, Technology and Medicine, Exhibition Road, South Kensington, London SW7 2AZ, United Kingdom.
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Skoutelis A, Dimitrakopoulos G, Bassaris H. False positive widal reaction in high-titer disseminated BCG infection. Eur J Clin Microbiol Infect Dis 1994; 13:261-3. [PMID: 8050442 DOI: 10.1007/bf01974548] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
False-positive Widal reactions following certain non-typhoid Salmonella infections may occur commonly. The case of a patient who developed miliary tuberculosis secondary to intravesical bacillus Calmette-Guérin (BCG) immunotherapy for bladder carcinoma is described. Very high titers of typhoid and paratyphoid agglutinins were obtained with the Widal test; these titers returned to normal after successful anti-tuberculous treatment. This case of high-titer, false-positive Salmonella typhi and Salmonella paratyphi A and B reactions to BCG infection occurred in an area non-endemic for typhoid or paratyphoid fever.
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Affiliation(s)
- A Skoutelis
- Department of Medicine, Patras University Medical School, University Hospital, Greece
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