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Likelihood of SARS-CoV-2 transmission in multi-bedded patient rooms by infecting variant
Anoshé Aslam1, Judy Yan1, Shauna Usiak1
1Infection Prevention and Control, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
Objective:
Sharing a room with an unrecognized contagious patient poses the greatest in-hospital risk of transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This study quantified secondary attack rates associated with exposure to the SARS-CoV-2 Omicron subvariant in an oncology centre.
Methods:
Patients with hospital-onset SARS-CoV-2 infection from 2021 to 2024 were evaluated for roommate exposure, with secondary attack rates stratified by the predominant circulating variant.
Results:
Among 299 patients who shared a room with a patient with hospital-onset SARS-CoV-2 infection, 17% developed secondary infection. Attack rates did not differ between the pre- and post-Omicron periods. Nearly half of the secondary cases were asymptomatic and, if unrecognized, could contribute to onward transmission within the hospital setting.
Conclusions:
High-risk hospital exposure to SARS-CoV-2 warrants monitoring for secondary infection to prevent onward transmission in vulnerable patients.
Insights
Hospital room sharing led to a 17% secondary infection rate for COVID-19 patients. Half of infections were asymptomatic, and attack rates remained consistent across variants.
Area of Science:
- Infectious Diseases
- Hospital Epidemiology
- Oncology
Background:
- Hospital-onset COVID-19 (HO-COVID-19) poses a significant risk to vulnerable patient populations.
- Understanding transmission dynamics within healthcare settings is crucial for infection control.
Purpose of the Study:
- To investigate the secondary infection rate among roommates of patients with HO-COVID-19.
- To analyze the clinical presentation and severity of infections in exposed roommates.
- To compare infection attack rates before and after the Omicron variant surge.
Main Methods:
- Retrospective analysis of 304 HO-COVID-19 cases at a cancer center (2021-2024).
- Identification of 299 patient-roommates exposed during the infectious period of index cases.
- Calculation of secondary infection rates, assessment of asymptomatic and severe infection proportions, and comparison of attack rates across different periods.
Main Results:
- Of 299 roommates, 17% (51) acquired secondary infections.
- Fifty percent (50%) of secondary infections were asymptomatic.
- Twelve percent (12%) of secondary infections progressed to severe disease.
- Secondary infection attack rates did not significantly differ between pre- and post-Omicron periods.
Conclusions:
- Room sharing in hospitals presents a notable risk for COVID-19 transmission.
- A significant proportion of secondary infections are asymptomatic, highlighting the challenge in identifying and isolating infectious individuals.
- The emergence of Omicron did not alter the transmission dynamics in this hospital setting.
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