Association Between Airborne Infection Isolation Room Utilization Rates and Healthcare Worker Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infections in 2 Academic Hospitals.

We compared healthcare worker severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection rates between March and August 2020 in 2 similar hospitals with high vs low airborne infection isolation room utilization rates but otherwise identical infection control policies. We found no difference in healthcare worker infection rates between the 2 hospitals, nor between patient-facing vs non-patient-facing providers.

Rapid Control of Hospital-Based Severe Acute Respiratory Syndrome Coronavirus 2 Omicron Clusters Through Daily Testing and Universal Use of N95 Respirators.

The highly contagious severe acute respiratory syndrome coronavirus 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.

The Risk of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Transmission from Patients With Undiagnosed Coronavirus Disease 2019 (COVID-19) to Roommates in a Large Academic Medical Center.

We assessed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission between patients in shared rooms in an academic hospital between September 2020 and April 2021. In total, 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 polymerase chain reaction (PCR) cycle thresholds ≤21.

Prospective Clinical Assessments of Hospitalized Patients With Positive SARS-CoV-2 PCR Tests for Necessity of Isolation.

We prospectively assessed 536 hospitalized patients with positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction tests for infectiousness based on symptoms, cycle thresholds, and SARS-CoV-2 history, with repeat testing and serologies in select cases. One hundred forty-eight (28%) patients were deemed noninfectious, most with evidence of prior infection, and managed on standard precautions without evidence of transmission.

Incidence of Nosocomial COVID-19 in Patients Hospitalized at a Large US Academic Medical Center.

Importance: Some patients are avoiding essential care for fear of contracting coronavirus disease 2019 (COVID-19) in hospitals. There are few data, however, on the risk of acquiring COVID-19 in US hospitals. Objective: To assess the incidence of COVID-19 among patients hospitalized at a large US academic medical center in the 12 weeks after the first inpatient case was identified. Design, Setting, and Participants: This cohort study included all patients admitted to Brigham and Women's Hospital (Boston, Massachusetts) between March 7 and May 30, 2020. Follow-up occurred through June 17, 2020. Medical records for all patients who first tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by reverse-transcription polymerase chain reaction (RT-PCR) on hospital day 3 or later or within 14 days of discharge were reviewed. Exposures: A comprehensive infection control program was implemented that included dedicated COVID-19 units with airborne infection isolation rooms, personal protective equipment in accordance with US Centers for Disease Control and Prevention recommendations, personal protective equipment donning and doffing monitors, universal masking, restriction of visitors, and liberal RT-PCR testing of symptomatic and asymptomatic patients. Main Outcomes and Measures: Whether infection was community or hospital acquired based on timing of tests, clinical course, and exposures. Results: Over the 12-week period, 9149 patients (mean [SD] age, 46.1 [26.4] years; median [IQR] age, 51 years [30-67 years]; 5243 female [57.3%]) were admitted to the hospital, for whom 7394 SARS-CoV-2 RT-PCR tests were performed; 697 COVID-19 cases were confirmed, translating into 8656 days of COVID-19-related care. Twelve of the 697 hospitalized patients with COVID-19 (1.7%) first tested positive on hospital day 3 or later (median, 4 days; range, 3-15 days). Of these, only 1 case was deemed to be hospital acquired, most likely from a presymptomatic spouse who was visiting daily and diagnosed with COVID-19 before visitor restrictions and masking were implemented. Among 8370 patients with non-COVID-19-related hospitalizations discharged through June 17, 11 (0.1%) tested positive within 14 days (median time to diagnosis, 6 days; range, 1-14 days). Only 1 case was deemed likely to be hospital acquired, albeit with no known exposures. Conclusions and Relevance: In this cohort study of patients in a large academic medical center with rigorous infection control measures, nosocomial COVID-19 was rare during the height of the pandemic in the region. These findings may inform practices in other institutions and provide reassurance to patients concerned about contracting COVID-19 in hospitals.