Published: Feb. 1, 2004

A new study that aims to significantly reduce the incidence of hospital-acquired infection by providing clear data on the effectiveness of ultraviolet germicidal irradiation (UVGI) is getting under way at the University of Colorado at Boulder.

The overall goal of the study, which is being funded by the N.G. Gilbert Foundation, is to quantify the effectiveness of ultraviolet germicidal irradiation, or UVGI, in controlling hospital-acquired infections from opportunistic airborne bacteria and fungi.

The research is being led by CU-Boulder engineering Professor Shelly L. Miller. Miller is an expert on indoor air quality, assessing exposures to infectious diseases and developing and evaluating control measures.

The rate of hospital-acquired infection has remained stable over the last 25 years at six per 100 hospital admissions, although the rate per 1,000 patient days has increased 36 percent because of shorter inpatient stays. In 1995, it was estimated that hospital-acquired infections resulted in medical costs of $4.5 billion and contributed to more than 88,000 deaths.

Miller has conducted previous studies on UVGI controls for reducing exposure to infectious diseases for the National Centers for Disease Control and Prevention and the National Science Foundation. The studies have looked at a variety of factors that can influence the effectiveness of UVGI but have shown that under the proper conditions, UVGI has significant potential to inactivate airborne bacteria and prevent infection in hospitals.

Two UVGI systems will be investigated in the new study: one is an in-room system that achieves irradiation of upper-room air through wall- and ceiling-mounted UV lamps; the second is an in-duct system installed in HVAC equipment.

The research will be conducted in two phases, the first of which will take place over a six-month period in a controlled laboratory setting at CU-Boulder's College of Engineering and Applied Science. Phase II will then involve controlled studies at the University of California-Los Angeles Medical Center.

The current design of Phase II includes testing first in unoccupied patient rooms retrofitted with proven UVGI systems, followed by detailed clinical studies of the effectiveness of UVGI against hospital-acquired infections.

The Gilbert Foundation hopes the study findings will be the catalyst for medical facilities to begin using UVGI on a comprehensive basis to significantly reduce hospital-acquired infections.