Nursing homes that utilize shared rooms and bathrooms for residents are at a higher risk of experiencing larger and more deadly COVID-19 outbreaks than facilities that house residents mostly in private rooms, a new study revealed. 

Researchers suggested that the findings support a reevaluation of current COVID-19 mitigation strategies for nursing homes, specifically cohorting tactics. 

“Our results suggest that cohorting may be ineffective in crowded homes with many shared rooms, as has been noted by nursing home administrators in Ontario,” Toronto-based research team members Kevin A. Brown, Ph.D., Aaron Jones, Nick Daneman, MD, et al., wrote. 

The investigation centered around more than 600 Ontario nursing homes that housed about 78,600 residents, and was conducted between the end of March and May. Of those residents, 36.9% were located in single rooms, 37.3% in double rooms and 25.8% in quadruple-bedded rooms. Additionally, 6.6% of the total residents contracted COVID-19, while 1.8% died of the disease. 

Three’s a crowd?

Researchers found that COVID-19 mortality rates were 2.7% in high crowding nursing homes, compared to 1.3% in low crowding nursing homes. Additionally, they found that outbreaks in crowded nursing homes tended to be larger. There were nine reported outbreaks involving more than 100 residents in high crowding facilities, compared to just 1 outbreak in low crowding homes. 

“Our findings align with a prior systematic review demonstrating that the risk of a respiratory infection in occupants of 2-bed rooms was double that of those in single-occupancy rooms. Physical barriers, such as walls separating bedrooms, predict deposition patterns of viral droplets more than absolute distances between beds in a shared room,” the team concluded. 

“Crowding can affect an entire home because higher risk among occupants of shared rooms may spillover to private room occupants as residents come into contact with each other directly, in common areas, or indirectly via health care workers,” they added. 

Investigators also said the findings suggest that cohorting infected residents together may be “ineffective in crowded homes with many shared rooms” and additional mitigation precautions may be needed in facilities with shared rooms and bathrooms. 

That could mean capping maximum room occupancy at two or retrofitting under occupied hotels to act as temporary nursing homes until rapid structural adaptations are made to homes that are overly crowded. 

Complete investigation findings were published Monday in JAMA Internal Medicine.