Diffractive Phase Interferometry (DPI), CRP and COVID-19 RT-PCR Tests in COVID-19 Patients with Different Ages in AJMAN, UAE: A Comparative Study

Abstract

Background: Fast and accurate diagnosis plays an important role in controlling and further preventing COVID-19. This study was conducted in the Thumbay laboratory of Gulf Medical University (Ajman, UAE) to assess the correlations between DPI (Diffractive Phase Interferometry), COVID-19 RT-PCR, and CRP tests in COVID-19 patients of different ages and to compare the effectiveness of each parameter. Methods and Results: A cross-sectional analytic study was conducted among 150 patients diagnosed with COVID-19 who were admitted to the Thumbay University Hospital. Their general data was collected from the LDM system, and from among the suspected patients who came to do the RT-PCR test, 230 were selected as volunteers to participate in this study, and further laboratory tests like CRP level and DPI test were done for them. The nasal swab was collected for a PCR test. Out of 230 nasal swab samples, 150 were positive and 80 were negative for SARS-CoV-2 RNA by real-time RT-PCR assay. Among the 150 positive RT-PCR, 90 false negative DPI tests were from a sample with a high real-time RT-PCR. While 60 true positive DPI tests were positive real-time RT-PCR for swab specimens. Among the 80 negative RT-PCR, 79 were true negative and 1 was a false positive. The predictive positive value of the DPI test was 40% and the predictive negative value of the test was 98%. DPI has at least one tie between the positive actual state group and the negative actual state group. The results show weak and moderate positive correlations between CRP and the age groups. Conclusion: The combined detection of the three indicators (RT-PCR, DPI, and CRP) are positively related to COVID-19 infection; therefore, these indicators will enable effective intervention measures to be implemented in time and the rates of severe illness and mortality to be reduced.

Keywords

• diffractive phase interferometry
• covid 19
• c-reactive protein
• polymerase chain reaction