Diagnostic performance of loop-mediated isothermal amplification (LAMP) and antigen test in comparison with reverse transcriptase-polymerization chain reactioin (RT-PCR) for detection of SARS-CoV-2 among patients presenting with COVID-19 symptoms in Mwanza, Tanzania
- Mwanza, Tanzania: Catholic University of Health and Allied Sciences [CUHAS – Bugando] : 2022
- 62 Pages Includes References and Appendices
Abstract:
Background: The Coronavirus diseases 2019 (COVID-19) pandemic which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reported for the first time in Wuhan, China in December 2019 and spread out all over the world. It has become not only a major health problem but also an economic and social problem. Because of the high global demand for SARS-CoV-2 test kits, the development and production of rapid test kits by various manufacturers in the world have rapidly scaled up with limited performance data from low- and middle-income countries (LMICs). The aim of this study was to compare the performance of antigen test with reverse transcriptase-polymerase chain reaction (RTPCR) for the detection of SARS-CoV-2 and determine the best duration of symptom onset for using AgRDT.
Methods: This cross-sectional study involved 503 samples conducted in Mwanza between May and August 2022. Demographic data and symptoms associated with SARS-CoV-2 infection were collected from COVID-19 investigation forms. Antigen rapid diagnostic test (Ag-RDT) was used to detect the presence of nucleocapsid protein antigen of the SARS-CoV-2 from nasal swabs specimens of the patients after RT-PCR assay as the gold standard. The data obtained were summarized in excel and analysed by using STATA 15.
Results: Out of 503 samples, 98 (20%) tested positive for both RT-PCR and Ag-RDT, 379 (75%) tested negative for both RT-PCR and Ag-RDT, and 26 (5%) samples had discordant results of RT-PCR positive and Ag-RDT negative. The overall diagnostic performance of Ag-RDT showed 79.03% sensitivity and 100% specificity. Ag- RDT show near-perfect agreement with RT-PCR with the value of 94.83% vs 65.47%. The Ag-RDT was more sensitive on the first four days of symptoms onset of COVID-19 with the sensitivity of 80.7% observed for a COVID-19 presumptive with cough and 87.1% for a COVID-19 presumptive with a combination of cough and fever.
Conclusion: The promising performance of Ag-RDT renders it useful as a screening tool alongside RTPCR to reduce transmission through improving contact tracing, implementation of local mitigation strategies, and refining existing testing protocol for diagnosis of COVID-19. Performing Ag-RDT, in early stages of SARS-CoV-2 infections in the presence of cough and fever significantly increase the sensitivity of the test.
= LIST OF ABBREVIATIONS ACE2 Angiotensin Converting Enzyme 2 AECOPD Acute Exacerbation of Chronic Obstructive Pulmonary Disease AKI Acute Kidney Injury ARDS Acute Respiratory Distress Syndrome BMC Bugando Medical Centre COVID-19 Coronavirus Disease 2019 CT Computed Tomography CUHAS Catholic University of Health and Allied Sciences HuCoV Human Coronavirus IFN Interferon LAMP Loop-Mediated Isothermal Amplification LMICs Low- and Middle-Income Countries LRTI Lower Respiratory Tract Infection MDA5 Melanoma Differentiation Associated Protein 5 nCoV New Coronavirus PAMP Pathogen Associated Molecular Pattern POC Point of Care PRR Pattern Recognition Receptor RBD Receptor Binding Domain RdRp RNA dependent RNA polymerase RDT Rapid Diagnostic Test RIG-1 Retinoic Acid Inducible Gene 1 RNA Ribonucleic Acidv RT-PCR Reverse Transcription-Polymerase Chain Reaction SARS-CoV-2 Severe Acute Respiratory Syndrome- Coronavirus 2 TLR Toll-Like Receptor TMPRSS2 Transmembrane Protease Serine 2 VTM Viral Transport Media WHO World Health Organization
Wurzburg Road 35, BMC Premises, Post Code: 33102: P. O Box 1464, Mwanza – Tanzania: Phone: +255 28 298 3384: Fax: +255 28 298 3386 Email: vc@bugando.ac.tz Website: www.bugando.ac.tz
--Clinical Microbiology and Diagnostic Molecular Biology --Biochemistry --Microbiology & Immunology