Nosocomial SARS-CoV-2 infection in patients with cancer: A four-year experience from a tertiary cancer center

Patients with cancer are at high risk of severe COVID-19 and nosocomial SARS-CoV-2 infection. This study aimed to describe the incidence, clinical characteristics, and outcomes of nosocomial COVID-19 among patients with solid tumors and hematologic malignancies.

To describe the incidence, clinical characteristics, and outcomes of nosocomial COVID-19 among patients with solid tumors and hematologic malignancies over 4 years.

We performed a retrospective study of patients with cancer and nosocomialCOVID-19 over four years. Incidence rates were calculated per1,000 patient-days. Clinical presentation, vaccination status, treatment, andoutcomes were described. Risk factors for 30-day mortality were evaluated usinglogistic regression.

Of 1,807 COVID-19 cases, 79 (4.4%) were hospital-acquired; incidence of0.36 per 1,000 patient-days. The incidence varied over time and peaked during theOmicron BA.1/BA.2 period. Thirty-day mortality was 19%, down from37.5% (2020) to 10% during Omicron; no deaths attributable to nosocomial COVID-19occurred in 2023-2024. In multivariable analysis, female sex (aOR 13.02, 95% CI1.71-99.00), critical COVID-19 at diagnosis (aOR 9.00, 95% CI 1.18-68.80), and SpO2<90% (aOR 5.92, 95% CI 1.19-29.58) were associated with 30-day mortality.

Nosocomial COVID-19 was low and generally tracked communitytransmission, except during the initial months of the pandemic. Mortality declined overtime; severe presentation and hypoxemia at diagnosis were associated with higherodds of death.