Environmental contamination with SARS-CoV-2 in nursing homes

Area of Science:

• Infectious Diseases
• Epidemiology
• Environmental Health

Background:

• Nursing home outbreaks of SARS-CoV-2 (the virus causing COVID-19) have been severe.
• Dedicated COVID-19 units were established in nursing homes to manage infected patients.
• The frequency and persistence of SARS-CoV-2 environmental contamination in these units remain understudied.

Purpose of the Study:

• To investigate the prevalence and persistence of SARS-CoV-2 environmental contamination in nursing home COVID-19 units.
• To identify patient risk factors associated with environmental contamination.

Main Methods:

• A prospective cohort study was conducted in four Michigan nursing homes from October 2020 to January 2021.
• Swabs of high-touch surfaces in COVID-19 patient rooms were collected at enrollment and follow-up.
• Multivariable logistic regression analyzed patient risk factors for contamination; Phi coefficients assessed site-specific contamination correlation.

Main Results:

• Nearly 90% of patients had SARS-CoV-2 contamination in their room at least once.
• SARS-CoV-2 RNA was detected on 28.4% of patient room surfaces versus 3.7% in common areas.
• Environmental contamination at enrollment correlated with follow-up contamination; functional independence increased contamination odds.

Conclusions:

• Viral RNA detection on surfaces in COVID-19 patient rooms is nearly universal and persistent.
• Further research is needed to understand the infectiousness implications of this environmental contamination.
• Patients with greater functional independence are more likely to contaminate their surrounding environment.