Cleaning the air with ultraviolet germicidal irradiation lessened contact infections in a long-term acute care hospital.

BACKGROUND: This study was designed to determine whether removing bacteria from the air with ultraviolet germicidal irradiation (UV-C) at the room level would reduce infection rates.

METHODS: We reviewed infection data for 12 months before and after UV-C installation in the special care unit (SCU) of a long-term acute care hospital. All patients admitted to the SCU during the study time frame were included. Microbiologic impactor air sampling was completed in August 2015. Shielded UV-C units were installed in 16 patient rooms, the hallway, and the biohazard room. Air sampling was repeated 81 days later.

RESULTS: After UV-C installation, airborne bacteria (colony forming units [CFU] per cubic meter of air) in patient rooms were reduced an average of 42% (175 vs 102 CFU/m3 ). Common health care-associated infections (HAIs) (Clostridium difficile [8 cases annually vs 1 case, P = .01] and catheter-associated urinary tract infection [20 cases annually vs 9 cases, P = .012]) were reduced significantly as were overall infections, in number of cases (average 8.8 per month vs 3.5, P < .001), and infection rate (average monthly rate 20.3 vs 8.6, P = .001), despite no reported changes to the amount or type of cleaning done, infection control protocols, or reporting procedures. Other infections, traditionally considered contact transmissible (central line-associated bloodstream infection and methicillin-resistant Staphylococcus aureus), also declined noticeably.

CONCLUSIONS: Continuous shielded UV-C reduced airborne bacteria and may also lower the number of HAIs, including those caused by contact pathogens. Reduced infections result in lessened morbidity and lower costs. Health care facilities might wish to consider continuous shielded UV-C at the room level as a possible addition to their infection prevention and control protocols.