This cohort study evaluates the incidence of nosocomial coronavirus disease 2019 (COVID-19) among patients admitted to a US medical center in the context of a comprehensive and progressive infection control program.

We assessed SARS-CoV-2 transmission between patients in shared rooms in an academic hospital between September 2020-April 2021. 11,290 patients were admitted to shared rooms, of whom 25 tested positive. Among 31 exposed roommates, 12 (39%) tested positive within 14 days. Transmission was associated with PCR cycle thresholds ≤21.

The highly contagious SARS-CoV-2 Omicron variant increases risk for nosocomial transmission despite universal masking, admission testing, and symptom screening. We report large increases in hospital-onset infections and 2 unit-based clusters. The clusters rapidly abated after instituting universal N95 respirators and daily testing. Broader use of these strategies may prevent nosocomial transmissions.

We prospectively assessed 536 hospitalized patients with positive SARS-CoV-2 PCR tests for infectiousness based on symptoms, cycle thresholds, and SARS-CoV-2 history, with repeat testing and serologies in select cases. 148 (28%) patients were deemed non-infectious, most with evidence of prior infection, and managed on standard precautions without evidence of transmission.

Background Burkholderia cepacia complex is a group of potential nosocomial pathogens often linked to contaminated water. We report on a cluster of 8 B.cepacia complex infections in cardiothoracic ICU patients attributed to contaminated ECMO water heaters. Methods In December 2020, we identified an increase in B.cepacia complex infections in the cardiothoracic ICU at Brigham and Women’s Hospital. We sought commonalities, sequenced isolates, obtained environmental specimens, and enacted mitigation measures. Results Whole genome sequencing of 13 B.cepacia complex clinical specimens between November 2020-February 2021 identified 6 clonally related isolates, speciated as Burkholderia contaminans. All 6 occurred in patients on ECMO. Microbiology review identified two additional B.contaminans cases from June 2020, including one ECMO patient, that may have been cluster-related as well. All 8 definite/probable cluster cases required treatment; 3 died and 3 developed recurrent infections. After ECMO was identified as the major commonality, all 9 of the hospital’s ECMO water heaters were cultured; all grew B.contaminans. Air sampling adjacent to the water heaters was culture-negative. Water heater touch screens were culture-positive for B.contaminans. The sink drain in the ECMO heater reprocessing room also grew clonal B.contaminans. Observations of reprocessing revealed opportunities for cross-contamination between devices via splash from the contaminated sink. The cluster was aborted by removing all water heaters from clinical service. Conclusions We identified a cluster of 8 B.cepacia complex infections associated with contaminated ECMO water heaters. This cluster underscores the potential risks associated with water-based ECMO heaters and, more broadly, water-based care for vulnerable patients.