Keywords
Salmonella Typhi
Salmonella Paratyphi
Blood culture
Rapid Diagnostic Tests (RDTs)
How to Cite
Abstract
Introduction: Typhoid and Paratyphoid fever are enteric infections caused by the bacteria Salmonella enterica serovar Typhi (S. Typhi) and S. Paratyphi A, B and C respectively. This research evaluated an immunochromatographic rapid diagnostic tests (RDT) Typhisure ©, for detection of S. Typhi and S. Paratyphi antigen in blood culture.
Objectives: To test for qualitative and differential detection of S. Typhi and S. Paratyphi antigen in human blood culture specimen by Typhisure .
Methodology: A descriptive cross-sectional study was conducted in a tertiary care hospital from August- October, 2024 after obtaining ethical clearance. Blood sample from 758 patients were collected aseptically. Rapid diagnostic test was performed by Typhisure on blood culture positive specimen and in parallel, conventional subculture, isolate identification was done.
Results: Among 758 blood culture specimen, 100 blood culture broth showing evidence of growth were further evaluated. Among these, Salmonella Paratyphi A was identified from 4 patients and Salmonella Typhi from 6 patients. The Typhisure RDT by Koshibio Diagnostics showed a sensitivity of 100% and specificity of 100% in detection of Salmonella Typhi from blood culture broth. Similarly, in all 4 Blood culture positive Salmonella Paratyphi, antigen was detected by Typhisure (Sensitivity 100%). However, one test came as false positive. two tests were considered invalid as the control line failed to appear in the kit.
Conclusion: Conventional blood culture broth with the RDT for antigen detection could pave a pathway forward for early diagnosis of enteric fever in resource limited setting like ours where Bactec, biochemical tests and Serotyping is not available in primary healthcare settings.
References
Khaliq A, Yousafzai MT, Haq S, Yaseen R, Quershi S, Rind F, et al. A review of toolkits and case definitions for detecting enteric fever outbreaks in Asian and African countries from 1965-2019. J Glob Health. 2021;11:04031. [PubMed | Full Text | DOI]
Saha T, Arisoyin AE, Bollu B, Ashok T, Babu A, Issani A, et al. Enteric fever: diagnostic challenges and the importance of early intervention. Cureus. 2023 Jul 13;15(7). [PubMed | Full Text | DOI]
Piankeu Y, Dahlia A, Fodouop, Chegaing SP, Noubom M, Djoumsie G, et al. Epidemiology and performances of Typhidot immunoassay and Widal slide agglutination in the diagnosis of typhoid fever in febrile patients in Bafoussam City, Cameroon: A cross-sectional comparative study. Can J Infect Dis Med Microbiol. 2024;6635067:15 pages. [PubMed | Full Text | DOI]
Kuijpers LMF, Chung P, Peeters M, Phoba MF, Kham C, Barbe B, et al. Diagnostic accuracy of antigen-based immunochromatographic rapid diagnostic tests for the detection of Salmonella in blood culture broth. PLoS One. 2018 Mar 7;13(3). [PubMed | Full Text | DOI]
Phillips MT, Antillon M, Bilcke J, Bar-Zeev N, Limani F, Debellut F, et al. Cost-effectiveness analysis of typhoid conjugate vaccines in an outbreak setting: a modeling study. BMC Infect Dis. 2023;23(1). [PubMed | Full Text | DOI]
Wijedoru L, Mallett S, Parry CM. Rapid diagnostic tests for typhoid and paratyphoid (enteric) fever. Cochrane Database Syst Rev. 2017 May 10;(5). [PubMed | Full Text | DOI]
Getahun Strobel A, Airs S, Nguyen C, et al. Assessment of rapid diagnostic tests for typhoid diagnosis and assessment of febrile illness outbreaks in Fiji. Am J Trop Med Hyg. 2022;106(2):543-549. [PubMed | Full Text | DOI]
Pokharel P, Rai SK, Karki G, Katuwal A, Vitrakoti R, Shrestha SK. Study of enteric fever and antibiogram of Salmonella isolates at a teaching hospital in Kathmandu Valley. Nepal Med Coll J. 2009 Sep 1;11(3):176-8. [PubMed | Full Text ]
Mejia N, Abimbola T, Andrews JR, Vaidya K, Tamrakar D, Pradhan S, et al. Typhoid and paratyphoid cost of illness in Nepal: patient and health facility costs from the Surveillance for Enteric Fever in Asia Project II. Am J Trop Med Hyg. 2020;71(Suppl 3). [PubMed | Full Text | DOI]
Tamrakar D, Vaidya K, Yu AT, Aiemjoy K, Naga SR, Cao Y, et al. Spatial heterogeneity of enteric fever in 2 diverse communities in Nepal. Clin Infect Dis. 2020;71(Suppl 3) –S213. [PubMed | Full Text | DOI]
Gasem MH, Smits HL, Goris MGA, Dolmans WMV. Evaluation of a simple and rapid dipstick assay for the diagnosis of typhoid fever in Indonesia. J Med Microbiol. 2002 Feb;51(2):173-177. [PubMed | Full Text | DOI]
Wijedoru L, Mallett S, Parry CM. Rapid diagnostic tests for typhoid and paratyphoid (enteric) fever. Cochrane Database Syst Rev. 2017 May 26;5(5) . [PubMed | Full Text | DOI]