Upper respiratory tract viral load quantification in COVID-19 patients at hospital admission and its association with disease severity.

ABSTRACT

INTRODUCTION: There are aspects of COVID-19 pathogenesis that are still unknown. OBJECTIVE: To determine the relationship between severity, mortality and viral replication in patients with COVID-19. METHODS: Clinical characteristics, severity and mortality of 203 patients hospitalized for COVID-19 were analyzed and correlated with viral load (VL) and threshold cycle (TC) at admission; nasopharyngeal swab was obtained. RESULTS: Mean VLs in surviving patients with mild to moderate, moderate to severe and severe disease were the following 6.8 x 106, 7.6 x 107 and 1.0 x 109, respectively; and in patients with critical disease who died, VL was 1.70 x 109. TCs were 26.06, 24.07, 22.66 and 21.78 for the same groups. In those who died, a higher mean VL was observed at admission in comparison with those who survived (1.7 x 109 vs. 9.84 x 106; p < 0.001). A significant correlation was observed between VL, severity and death (r = 0.254, p < 0.045 and r = 0.21, p < 0.015). High VL was associated with increased in-hospital mortality in comparison with low VL (OR = 2.926, p < 0.017). CONCLUSION: SARS-CoV-2 VL determined at hospital admission might classify risk simultaneously with other factors described in COVID-19.

RESUMEN

INTRODUCCIÓN: Aún se desconocen aspectos de la patogenia de COVID-19. OBJETIVO: Determinar la relación entre gravedad, mortalidad y replicación viral en pacientes con COVID-19. MÉTODOS: Se analizaron características clínicas, gravedad de la enfermedad y mortalidad de 203 pacientes hospitalizados por COVID-19 y se correlacionaron con carga viral (CV) y ciclo umbral (Ct) al ingreso; se tomó hisopado nasofaríngeo. RESULTADOS: Las CV medias en los pacientes sobrevivientes fueron las siguientes ante enfermedad leve a moderada, moderada a grave y grave 6.8 × 106, 7.6 × 107 y 1.0 × 109; y en los pacientes con enfermedad crítica que fallecieron, la CV fue de 1.70 × 109. Los Ct fueron 26.06, 24.07, 22.66 y 21.78 para esos mismos grupos. En quienes fallecieron se observó mayor CV media al ingreso en comparación con quienes sobrevivieron (1.7 × 109 versus 9.84 × 106), p < 0.001. Se evidenció correlación significativa entre CV, gravedad y muerte (r = 0.254, p < 0.045 y r = 0.21, p < 0.015). La CV alta se asoció a mayor mortalidad intrahospitalaria en comparación con la CV baja (RM = 2.926, p < 0.017). CONCLUSIÓN: La CV de SARS-CoV-2 determinada al ingreso hospitalario podría calificar el riesgo simultáneamente con otros factores descritos en COVID-19.