Initial SARS-CoV-2 viral load is associated with disease severity: a retrospective cohort study

Abstract

BackgroundWe aimed to assess the association between initial SARS-CoV-2 viral load and the subsequent hospital and intensive care unit (ICU) admission and overall survival.MethodsAll persons with a positive SARS-CoV-2 RT-PCR result from a combined nasopharyngeal (NP) and oropharyngeal (OP) swab (first samples from unique persons only) that was collected between March 17, 2020, and March 31, 2021, in Public Health testing facilities in the region Kennemerland, province of North Holland, the Netherlands were included. Data on hospital (and ICU) admission were collected from the two large teaching hospitals in the region Kennemerland.ResultsIn total, 20,207 SARS-CoV-2 positive persons were included in this study, of whom 310 (1.5%) were hospitalized in a regional hospital within 30 days of their positive SARS-CoV-2 RT-PCR test. When persons were categorized in three SARS-CoV-2 viral load groups, the high viral load group (Cp < 25) was associated with an increased risk of hospitalization as compared to the low viral load group (Cp > 30) (ORadjusted [95%CI]: 1.57 [1.11-2.26], p-value=0.012), adjusted for age and sex. The same association was seen for ICU admission (ORadjusted [95%CI]: 7.06 [2.15-43.57], p-value=0.007). For a subset of 243 of the 310 hospitalized patients, the association of initial SARS-CoV-2 Cp-value with in-hospital mortality was analyzed. The initial SARS-CoV-2 Cp-value of the 17 patients who deceased in the hospital was significantly lower (indicating a higher viral load) compared to the 226 survivors: median Cp-value [IQR]: 22.7 [3.4] vs. 25.0 [5.2], OR[95%CI]: 0.81 [0.68-0.94], p-value = 0.010.ConclusionsOur data show that higher initial SARS-CoV-2 viral load is associated with an increased risk of hospital admission, ICU admission, and in-hospital mortality. We believe that our findings emphasize the added value of reporting SARS-CoV-2 viral load based on Cp-values to identify persons who are at the highest risk of adverse outcomes such as hospital or ICU admission and who therefore may benefit from more intensive monitoring.

Severe Acute Respiratory Syndrome Coronavirus 2 and Blood Safety: An Updated Review

“…The proportion of patients with detectable RNA­aemia varies substantially between studies, from approximately 1–50% for mild infections [ 58 , 59 , 60 , 61 ], up to 88% in patients with severe COVID-19 [ 59 , 61 , 62 , 63 ] and up to 100% in critically ill patients [ 59 , 61 ]. Detectable RNA­aemia is a risk factor for severe disease and mortality, the risk increasing with higher levels of RNAaemia and lower reverse transcriptase polymerase chain reaction cycle threshold values [ 59 , 60 , 63 , 64 , 65 , 66 , 67 , 68 ], and a predictor of post-acute symptoms [ 69 ].…”

Is SARS‐CoV‐2 viral clearance in nasopharyngeal swabs an appropriate surrogate marker for clinical efficacy of neutralising antibody‐based therapeutics?

“…Although PCR can also detect non‐infectious, immune‐complexed viral particles, the correlation of viral load in NPS with infectious SARS‐CoV‐2 has been established in large studies 7,8 . Viral load may correlate with infectivity, disease phenotype and morbidity in COVID‐19 patients, although a higher initial SARS‐CoV‐2 viral load was associated with increased risk of hospital admission, intensive care unit (ICU) admission and in‐hospital mortality in some 9 but not in other studies 10 . Nonetheless, SARS‐CoV‐2 viral load at diagnosis was an independent predictor of mortality in a large, hospitalised cohort study (hazard ratio 1.07, with a 7% increase in hazard for each log transformed copy per millilitre) 11 …”