305. Clinical scoring system to predict viable viral shedding in patients with COVID-19

Abstract

Abstract Background Centers for Disease Control and Prevention (CDC) recommends 5 to 20 days of isolation for COVID-19 patients depending on symptom duration and severity regardless of genomic PCR results or vaccination history. However, in real clinical practice, more individualized approach is required. We thus developed clinical scoring system to predict viable viral shedding in a given patient by using various factors affecting viable viral shedding. Methods We prospectively enrolled adult patients with SARS-CoV-2 infection admitted to tertiary hospital and day care center between February 2020 and January 2022. The daily dense respiratory sampling (i.e. saliva, sputum, or nasopharyngeal swabs) during the hospital and day care center stay were obtained. Genomic RNA viral load and viral culture were performed for these samples. Clinical predictors of negative viral culture results were identified using survival analysis and multivariable analysis. Results A total of 612 samples from 121 patients of varying degrees of severity were obtained. Of these, 494 (81%) samples were saliva, 63 (10%) were nasopharyngeal swab, and the remaining 55 (9%) were sputum. Of these 612 specimens, 154 (25%) samples revealed positive viral culture results. Univariate and multivariable Cox's time varying proportional hazard model revealed that symptom onset day, viral copy number, disease severity, organ transplant recipient, gender, and vaccination status were independently associated with viral culture results. We thus developed the 5-factor model from -3 to 3 points: viral copy number (-3 to 3 points depending on copy number), disease severity (1 point to moderate to critical diseases), organ transplant recipient (2 points), gender (-1 points to male), and vaccination status (-2 points to fully vaccinated status). The predictive culture-negative rates were calculated through the symptom onset day and the score of the day the sample was collected. Table 1.Prediction scores for negative viral culture resultsTable 2.Predicted Culture-negative Rates Values in the table expressed as percentages. Conclusion Our clinical scoring system can provide objective probability of negative culture results in a given COVID-19 patient with genomic viral load, and appears to be useful to decide de-isolation policy depending on individualized factors associated with viable viral shedding beyond simple symptom-based isolation strategy by CDC. Disclosures All Authors: No reported disclosures.