The COVID-19 pandemic led to a global increase in healthcare-associated infections (HAIs) among intensive care unit (ICU) patients. Whether this increase is directly attributable to COVID-19 or whether the pandemic indirectly (via staff shortages or breaches in infection prevention measures) led to this increase, remains unclear. The objectives of this study by Bloch, et al. (2023) were to assess HAI incidence and to identify independent risk factors for HAIs in COVID-19 and non-COVID-19 ICU patients.

The researchers established a monocentric prospective HAI surveillance in the medical ICU of our tertiary care center from Sept. 1, 2021 until Aug. 31, 2022, during circulation of the SARS-CoV-2 delta and omicron variants. They consecutively included patients ≥18 years of age with an ICU length of stay of >2 calendar days. HAIs were defined according to the European Centre for Disease Prevention and Control definitions. HAI rate was calculated per 1,000 patient-days or device-days; risk ratios (RR) and corresponding 95% confidence intervals (CI) for COVID-19 versus non-COVID-19 patients were calculated.

The researchers included 254 patients, 64 (25.1%) COVID-19 and 190 (74.9%) non-COVID-19 patients; 83 HAI in 72 patients were recorded, thereof 45 ventilator-associated lower respiratory tract infections (VA-LRTI) (54.2%) and 18 bloodstream infections (BSI) (21.6%). HAI incidence rate was 49.1/1,000 patient-days in COVID-19 and 22.5/1,000 patient-days in non-COVID-19 patients (RR 2.2, 95%-CI 1.4–3.4). This result was mainly due to different VA-LRTI rates (40.3 vs. 11.7/1,000 ventilator days, p < 0.001), whereas BSI rates were not statistically different (9.4 vs. 5.6/1,000 patient days, p = 0.27). Multivariable analysis identified COVID-19 as main risk factor for HAI development, whereas age, mechanical ventilation and COVID-19 density were not significant.

These data from the fourth and fifth wave of the pandemic show a higher HAI incidence in COVID-19 than in non-COVID-19 ICU patients, mainly due to an increase in pulmonary infections, the authors say. A diagnosis of COVID-19 was independently associated with HAI development, whereas institutional COVID-19 burden was not.

Reference: Bloch N, et al. Healthcare‑associated infections in intensive care unit patients with and without COVID-19: a single center prospective surveillance study. Antimicrobial Resistance & Infection Control. Vol. 12, article number 147 (2023).