Vulnerability of hospitalized patients during community disease outbreaks: Lessons from the early COVID-19 pandemic

Hospital-acquired infections (HAIs) during community disease outbreaks threaten vulnerable hospitalized patients. This study compares the outcomes of hospitalized patients who had COVID-19 as either a HAI or a community-acquired infection (CAI).

We conducted a retrospective cohort study involving adult patients hospitalized across 39 greater Paris University hospitals between January 27th, 2020, and April 21st, 2021, who tested positive for SARS-CoV-2 PCR during their stay. Patients were classified as CAI if they tested positive within 72hours of admission and HAI if they tested negative within 72hours but later positive. HAI was subclassified as possible (first positive test between days 4-7), probable (days 8-13), or definite (day 14 onward). Patients with probable or definite HAI were matched 1:3 to CAI patients for age, sex, and comorbidities, to compare intensive care unit (ICU) transfer and in-hospital death between both groups.

Of 10,831 patients, 506 (4.7%) were classified as HAI. They were older and had more comorbidities. After matching, the 333 patients with probable or definite HAI were less likely to be transferred to the ICU (hazard ratio [HR] 0.57, 95% CI 0.38-0.85) compared to their 999 CAI controls and had a higher risk for in-hospital death (HR 1.58, 95% CI 1.16-2.14).

Patients with COVID-19 as a HAI face a higher risk of death compared to patients hospitalized with COVID-19 acquired in the community and are less likely to be admitted to the ICU. Strict infection control measures are needed during community outbreaks to protect hospitalized patients.