Study Reports Mixed Results on Germicidal UV Light Effectiveness

Germicidal ultraviolet (GUV) air sterilization appliances, also known as UV germicidal irradiation (UVGI) appliances, use UV light to kill airborne viral, bacterial, and fungal organisms as they pass through a disinfection zone.

The COVID-19 pandemic brought a renewed focus on infection control and prevention practices, including the need for effective strategies to reduce airborne pathogen transmission. GUV appliances can be used with minimal disruption and represent a potential adjunct to existing infection control measures. However, despite growing interest in this technology, a study by the Journal of the American Medical Association (JAMA) highlighted limited success.

JAMA conducted a clinical trial in Australia, where it reported the use of GUV appliances in communal areas resulted in a nonsignificant decrease in acute respiratory infection (ARI) rates. However, time-series modeling showed a statistically significant 12.2% reduction in weekly ARIs. This difference in findings likely reflects the random timing of infections, variations in infection rates, and external environmental factors.

The study further estimated the causal effect of the intervention to be an approximately 9% reduction in infections. When applied to the ARI rate in the control arm, such a reduction equates to 92 fewer ARIs per 1,000 residents annually.

While falling short of the 20% benchmark that is often considered a clinically meaningful change for an individual, such a reduction could translate to a very meaningful effect from a public health perspective, for which the aggregate benefit of even small individual improvements becomes substantial.