New <i>Legionella</i> Control Options by UV and Violet LEDs for Hospitals and Care Facilities

Abstract

<em>Legionella</em> infections caused by contaminated water are a widespread problem worldwide. Discharge lamps like mercury vapor lamps are widely known for the disinfection properties of their radiation, but they suffer technical disadvantages, like high voltages and toxic content, and are, therefore, not suitable for some infection control applications. New high-intensity ultraviolet (UV) and violet LEDs offer new approaches for <em>Legionella</em> control, because these bacteria are significantly light sensitive compared to other pathogens. One of the most important infection pathways is the inhalation of <em>Legionella</em>-containing aerosols during showering. This problem could be reduced by a single strong UV LED within the shower head, which irradiates the passing water for some milliseconds. This practice can be especially beneficial in hospitals and care facilities. UV light offers only a limited penetration depth, however, even in pure water. To disinfect larger water volumes, e.g., in water dispensers, visible violet LEDs are more appropriate. Unfortunately, up to now, neither approach has been given much attention by potential users.