Viral load and disease severity in COVID-19

Abstract

The relationship between COVID-19 severity and viral load is unknown. Our objective was to assess the association between viral load and disease severity in COVID-19. In this single center observational study of adults with laboratory confirmed SARS-CoV-2, the first positive in-hospital nasopharyngeal swab was used to calculate the log10 copies/ml [log10 copy number (CN)] of SARS-CoV-2. Four categories based on level of care and modified sequential organ failure assessment score (mSOFA) at time of swab were determined. Median log10CN was compared between different levels of care and mSOFA quartiles. Median log10CN was compared in patients who did and did not receive influenza vaccine, and the correlation between log10CN and D-dimer was examined. We found that of 396 patients, 54.3% were male, and 25% had no major comorbidity. Hospital mortality was 15.7%. Median mSOFA was 2 (IQR 0–3). Median log10CN was 5.5 (IQR 3.3–8.0). Median log10CN was highest in non-intubated ICU patients [6.4 (IQR 4.4–8.1)] and lowest in intubated ICU patients [3.6 (IQR 2.6–6.9)] ( p value < 0.01). In adjusted analyses, this difference remained significant [mean difference 1.16 (95% CI 0.18–2.14)]. There was no significant difference in log10CN between other groups in the remaining pairwise comparisons. There was no association between median log10CN and mSOFA in either unadjusted or adjusted analyses or between median log10CN in patients with and without influenza immunization. There was no correlation between log10CN and D-dimer. We conclude, in our cohort, we did not find a clear association between viral load and disease severity in COVID-19 patients. Though viral load was higher in non-intubated ICU patients than in intubated ICU patients there were no other significant differences in viral load by disease severity. Supplementary Information The online version contains supplementary material available at 10.1007/s11739-021-02786-w.

COVID-19 in elderly: Correlations of viral load, clinical course, laboratory parameters, among patients vaccinated with CoronaVac

“…In this research, COVID-19 patients with high SARS-CoV-2 viral load had a greater risk of severe/critical presentation. Some investigations have demonstrated that SARS-CoV-2 viral loads on the upper respiratory tract are positively linked with illness severity, which is consistent with our findings [21][22][23][24]. Others, on the other hand, have found no link [25][26][27].…”

Remdesivir significantly reduces SARS‐CoV‐2 viral load on nasopharyngeal swabs in hospitalized patients with COVID‐19: A retrospective case–control study

“…It represents a reliable, semi‐quantitative, indicator of the presence viral genetic material inversely correlated to VL. 10 The cut‐off value of CT was 35 (e.g., ≤35 positive/>35 negative) according to manufacturer indications. However, the results of the test were analysed automatically and interpreted by the instrument software with the parameters included in the Assay Protocol.…”

“… 3 , 4 , 5 , 6 Although remdesivir shows a significant in vitro activity in terms of reduction of viral load (VL) from respiratory specimens, 7 its effectiveness on clinical outcomes is still matter of debate. 8 In addition, evidences on the correlation between VL and clinical severity are controversial, 9 , 10 , 11 even if it has been shown that patients with more severe disease could present with a slower VL clearance. 7 At present, studies focusing on the effect of remdesivir on VL are few and with contrasting results.…”

COVID-19: Azelastine nasal spray Reduces Virus-load In Nasal swabs (CARVIN) Early intervention with azelastine nasal spray may reduce viral load in SARS-CoV-2 infected patients – results from a randomized, double-blind, placebo-controlled phase II clinical trial.

“…It should be pointed out that the mean viral load value showed small variability, thereby supporting the power of the current study despite its overall small numbers. The higher viral load value in our study population may be explained with the dominance of the alpha (B.1.1.7) SARS-CoV-2 variant during the enrollment phase (Spring 2021, Germany), which is known to infect the human nasal mucosa more e ciently than the wild-type and has been associated with higher viral load (12,13) . Indeed, the majority of the study subjects carried this variant.…”

“…The sample size calculation was based on the expected reduction of virus load during the treatment considering 3 treatment arms. It was assumed that all treatment groups present identical baseline virus load at enrolment with a mean value of 5•5 log 10 copies/mL ± 3 SD (12,13) . Since azelastine has been shown to inhibit viral replication by 99•9% in Vero E6 cell culture and in reconstituted human nasal tissue cultures, it was assumed that a reduction of 3-log in virus load would be seen within 3 days in actively treated patients, while no effect on virus load reduction would be seen in placebo treated patients.…”