The Association of RT-PCR Cycle Threshold Value with Timing of Sample Collection and Presenting Manifestations of COVID-19 Among Pediatric Patients Admitted in a Tertiary Hospital in Davao City

Background: Cycle threshold (Ct) value has gained clinical attention in the study of COVID-19 as it has been used as an indirect method of quantifying the viral RNA in a specimen. Investigating its utility will aid in discovering transmission dynamics and clinical decision-making. Objective: To determine the association between the RT-PCR Ct value with the timing of sample collection and presenting manifestations of COVID-19 among pediatric patients. Methods: A retrospective, analytical, cross sectional research was done which included all patients with a positive RT-PCR admitted in a private tertiary hospital in Davao City. Ct values and clinical and demographic data were retrieved. Descriptive statistics were used to present and analyze the profiles. Independent t-test, analysis of variance and Pearson r were used for comparison and correlation of variables. Results: A total of 48 subjects were included in the study. Of the presenting manifestations, the most common were fever and cough. There was no significant difference in the Ct values of the different presenting manifestations. There was a weak positive correlation between Ct value and time of sample collection (r 0.3027). A weak negative correlation between Ct value and number of presenting manifestations was also noted (r -0.2045). Conclusion: Ct value increases with time and is significantly low during the first three days of illness. There is no significant difference in the mean Ct values of the different presenting manifestations. Furthermore, the higher number of presenting manifestations is associated with lower Ct values.