Few bacterial co-infections but frequent empiric antibiotic use in the early phase of hospitalized patients with COVID-19: results from a multicentre retrospective cohort study in The Netherlands
retrospective cohort study in The Netherlands
Zara Karamia,, Bram T. Knoop,, Anton S. M. Dofferhoffc, Marc J. T. Blaauw, Nico A. Janssen, Marjan van Apeldoorne, Angele P. M. Kerckhoffse, Josephine S. van de Maat, Jacobien J. Hoogerwerf and Jaap ten Oever, Radboud University Medical Center, Nijmegen, The Netherlands; bRadboud Center for Infectious diseases, Nijmegen, The
Netherlands; Canisius Wilhelmina Ziekenhuis, Nijmegen, The Netherlands; Bernhoven University, Uden, The Netherlands;
Jeroen Bosch Ziekenhuis, Den Bosch, The Netherlands
Background: Knowledge on bacterial co-infections in COVID-19 is crucial to use antibiotics appropriately. Therefore, we
aimed to determine the incidence of bacterial co-infections, antibiotic use and application of antimicrobial stewardship
principles in hospitalized patients with COVID-19.
Methods: We performed a retrospective observational study in four hospitals (1 university, 2 non-university teaching,
1 non-teaching hospital) in the Netherlands from March to May 2020 including consecutive patients with PCR-confirmed
COVID-19. Data on first microbiological investigations obtained at the discretion of the physician and antibiotic use in the
first week of hospital admission were collected.
Results: Twelve (1.2%) of the 925 patients included had a documented bacterial co-infection (75.0% pneumonia) within the first
week. Microbiological testing was performed in 749 (81%) patients: sputum cultures in 105 (11.4%), blood cultures in 711 (76.9%),
pneumococcal urinary antigen testing in 202 (21.8%), and Legionella urinary antigen testing in 199 (21.5%) patients, with clear variation
between hospitals. On presentation 556 (60.1%; range 33.3–73.4%) patients received antibiotics for a median duration of 2 days
(IQR 1–4). Intravenous to oral switch was performed in 41 of 413 (9.9%) patients who received intravenous treatment >48h. Mean
adherence to the local guideline on empiric antibiotic therapy on day 1 was on average 60.3% (range 45.3%–74.7%).
Conclusions: On presentation to the hospital bacterial co-infections are rare, while empiric antibiotic use is abundant. This
implies that in patients with COVID-19 empiric antibiotic should be withheld. This has the potential to dramatically reduce
the current overuse of antibiotics in the COVID-19 pandemic.