Studying the correlation of cycle threshold value of RT-PCR and computed tomography score of CT-Scan in covid-19 infection

ABSTRACT

Background: The COVID-19 pandemic has unfolded as one of the world's worst health crisis. Viral RT-PCR, CRP, and CT scan thorax are the most common tools used for its diagnosis, prognosis and severity assessment. Hence, a parallel between these parameters can aid in better understanding and management of COVID-19 infection. Methodology: Demographic data, history, cycle threshold values of RT-PCR from nasopharyngeal and oropharyngeal swabs, CRP and computed tomography score were obtained from 108 adult participants. Statistical analysis was performed using python programming (python 3.7) and inbuilt libraries. Result(s) Mean age of the study group was 51.05 years. 63.89% were males. The mean CT score was 15.417 indicating severe disease. Men had a higher CRP. Cycle threshold value of N gene was directly proportional to CT score. Lower cycle threshold values were associated with higher CRP. Of the 37 deaths, 62.16% were males. Cycle threshold in non-survivors was significantly higher than survivors indicating lower nasopharyngeal viral load in non-survivors. Diabetes was the most common comorbidity associated with mortality. Conclusion(s) Nasopharyngeal load can be low even with severe radiological CT findings probably due to migration of the virus to lower respiratory tract in later stages of the disease. Low nasopharyngeal viral loads cannot negate the possibility of a severe pulmonary infection. CRP values may not always correlate with CT findings in recovering stages of disease. Comorbidities adversely affect the disease outcome. These parameters should be used in conjunction to assess and veer the progression, management and outcome of patients with COVID-19 infection. Copyright © 2023 Ubiquity Press. All rights reserved.