AIDS 2020 – Prolonged viral shedding, longer time to hospitalization linked to poor viral clearance in Italian COVID-19 patients

  • Liz Scherer
  • Conference Reports
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  • Higher risk of prolonged viral shedding in coronavirus disease (COVID-19) patients appears to be driven by delayed hospital admission (postsymptom onset [PSO]), disease severity, and baseline comorbid conditions according to Italian study findings.
  • Further data on viral shedding duration and associated factors needed.

Why this matters

  • Promptly hospitalize and initiate management in COVID-19 patients, especially in persons with comorbidities and respiratory failure. 

Key results

  • 316 patients, 68% male; median age, 62 (interquartile range [IQR], 50-75) years; 60% had comorbidities.
  • Median days to hospital admission PSO: 7 (IQR, 4-11) days and to start therapy: 8 (IQR, 5-10) days.
  • Antiviral therapy initiated in 285 patients, 78% on admission; 38% placed on invasive mechanical ventilation (MV).
  • Median follow-up of 11 days, 59% developed PaO2/FiO2
  • 66% achieved viral clearance with median 17 (IQR, 11-23) days PSO; 20 and 30 days probability of VC was 51% (95% CI, 44.9%-57.2%) and 78.2% (95% CI, 72.2%-83.7%), respectively.
  • Multivariable Poisson: baseline comorbidities (adjusted incidence rate ratio [aIRR], 0.90; P=.049) and PaO2/FiO2
  • Stratified by severity: patients with PaO2/FiO2 ≥300 with symptoms >16-day preadmission less likely to achieve VC (aIRR, 0.47; P=.042).
  • In inverse probability weighted Cox model, shorter viral shedding linked to higher clinical recovery (adjusted HR, 2.76; 95% CI, 1.96-3.88).

Study design

  • Observational, retrospective, single-center cohort evaluation of time to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral clearance, predictive factors, probability of clinical recovery, invasive MV among Italian patients with confirmed COVID-19 infection.
  • Funding: None disclosed.


  • Observational, residual, unmeasured confounders.
  • Selection bias.


“Despite large amounts of recent data on SARS-CoV-2, viral dynamics are still poorly understood,” said lead investigator Annalisa Mondi from the National Institute for Infectious Diseases in Milan. Findings highlight that a more rapid achievement of viral clearance fitted with a better clinical outcome, she said.