Hospital-Acquired Infections in Critically Ill Patients With COVID-19

Giacomo Grasselli, Vittorio Scaravilli, Davide Mangioni, Luigia Scudeller, Laura Alagna, Michele Bartoletti, Giacomo Bellani, Emanuela Biagioni, Paolo Bonfanti, Nicola Bottino, Irene Coloretti, Salvatore Lucio Cutuli, Gennaro De Pascale, Daniela Ferlicca, Gabriele Fior, Andrea Forastieri, Marco Franzetti, Massimiliano Greco, Amedeo Guzzardella, Sara LinguadocaMarianna Meschiari, Antonio Messina, Gianpaola Monti, Paola Morelli, Antonio Muscatello, Simone Redaelli, Flavia Stefanini, Tommaso Tonetti, Massimo Antonelli, Maurizio Cecconi, Giuseppe Foti, Roberto Fumagalli, Massimo Girardis, Marco Ranieri, Pierluigi Viale, Mario Raviglione, Antonio Pesenti, Andrea Gori, Alessandra Bandera

Research output: Contribution to journalArticlepeer-review


Background: Few small studies have described hospital-acquired infections (HAIs) occurring in patients with COVID-19. Research Question: What characteristics in critically ill patients with COVID-19 are associated with HAIs and how are HAIs associated with outcomes in these patients? Study Design and Methods: Multicenter retrospective analysis of prospectively collected data including adult patients with severe COVID-19 admitted to eight Italian hub hospitals from February 20, 2020, through May 20, 2020. Descriptive statistics and univariate and multivariate Weibull regression models were used to assess incidence, microbial cause, resistance patterns, risk factors (ie, demographics, comorbidities, exposure to medication), and impact on outcomes (ie, ICU discharge, length of ICU and hospital stays, and duration of mechanical ventilation) of microbiologically confirmed HAIs. Results: Of the 774 included patients, 359 patients (46%) demonstrated 759 HAIs (44.7 infections/1,000 ICU patient-days; 35% multidrug-resistant [MDR] bacteria). Ventilator-associated pneumonia (VAP; n = 389 [50%]), bloodstream infections (BSIs; n = 183 [34%]), and catheter-related BSIs (n = 74 [10%]) were the most frequent HAIs, with 26.0 (95% CI, 23.6-28.8) VAPs per 1,000 intubation-days, 11.7 (95% CI, 10.1-13.5) BSIs per 1,000 ICU patient-days, and 4.7 (95% CI, 3.8-5.9) catheter-related BSIs per 1,000 ICU patient-days. Gram-negative bacteria (especially Enterobacterales) and Staphylococcus aureus caused 64% and 28% of cases of VAP, respectively. Variables independently associated with infection were age, positive end expiratory pressure, and treatment with broad-spectrum antibiotics at admission. Two hundred thirty-four patients (30%) died in the ICU (15.3 deaths/1,000 ICU patient-days). Patients with HAIs complicated by septic shock showed an almost doubled mortality rate (52% vs 29%), whereas noncomplicated infections did not affect mortality. HAIs prolonged mechanical ventilation (median, 24 days [interquartile range (IQR), 14-39 days] vs 9 days [IQR, 5-13 days]; P < .001), ICU stay (24 days [IQR, 16-41 days] vs 9 days [IQR, 6-14 days]; P = .003), and hospital stay (42 days [IQR, 25-59 days] vs 23 days [IQR, 13-34 days]; P < .001). Interpretation: Critically ill patients with COVID-19 are at high risk for HAIs, especially VAPs and BSIs resulting from MDR organisms. HAIs prolong mechanical ventilation and hospitalization, and HAIs complicated by septic shock almost double mortality. Trial Registry:; No.: NCT04388670; URL:

Original languageEnglish
Pages (from-to)454-465
Number of pages12
Issue number2
Publication statusPublished - Aug 2021


  • COVID-19
  • critical care
  • hospital-acquired infections
  • SARS-CoV-2

ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine
  • Critical Care and Intensive Care Medicine
  • Cardiology and Cardiovascular Medicine


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