Background Despite the limitations in the use of cycle threshold (CT) values for individual patient care, population distributions of CT values may be useful indicators of local outbreaks. Objective We aimed to conduct an exploratory analysis of potential correlations between the population distribution of cycle threshold (CT) values and COVID-19 dynamics, which were operationalized as percent positivity, transmission rate (R t ), and COVID-19 hospitalization count. Methods In total, 148,410 specimens collected between September 15, 2020, and January 11, 2021, from the greater El Paso area were processed in the Dascena COVID-19 Laboratory. The daily median CT value, daily R t , daily count of COVID-19 hospitalizations, daily change in percent positivity, and rolling averages of these features were plotted over time. Two-way scatterplots and linear regression were used to evaluate possible associations between daily median CT values and outbreak measures. Cross-correlation plots were used to determine whether a time delay existed between changes in daily median CT values and measures of community disease dynamics. Results Daily median CT values negatively correlated with the daily R t values ( P <.001), the daily COVID-19 hospitalization counts (with a 33-day time delay; P <.001), and the daily changes in percent positivity among testing samples ( P <.001). Despite visual trends suggesting time delays in the plots for median CT values and outbreak measures, a statistically significant delay was only detected between changes in median CT values and COVID-19 hospitalization counts ( P <.001). Conclusions This study adds to the literature by analyzing samples collected from an entire geographical area and contextualizing the results with other research investigating population CT values.
【저자키워드】 COVID-19, Epidemiology, Transmission, Population, reverse transcription polymerase chain reaction, Testing, cycle threshold, correlation, Rt, exploratory, threshold, disease dynamic, distribution, 【초록키워드】 Measures, cycle threshold, outbreak, hospitalizations, Research, Community, Ct value, Linear regression, COVID-19 hospitalization, disease, association, Ct values, geographical area, population distribution, population distributions, Patient care, Exploratory analysis, average, specimen, measure, limitation, local outbreaks, transmission rate, Daily, objective, feature, Result, greater, collected, evaluate, median, were used, determine, changes in, correlated, statistically significant, processed, scatterplot, 【제목키워드】 SARS-CoV-2, cycle, value,