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New Research Shows UV-C Exposure Time and Distance Matter in Fighting Candida auris

September 2026 | This Too LLC News

Researchers studying Candida auris, an emerging fungal pathogen associated with healthcare outbreaks, have found that ultraviolet-C (UV-C) light can reduce the organism on surfaces—but the effectiveness depends heavily on how long the surface is exposed and how far it is from the UV-C source.

The findings were published in Mycoses in a study led by researchers from the Netherlands and India.

Why Candida auris Matters

Candida auris has become an important healthcare concern because it can cause serious infections and can persist on surfaces and patient-care equipment. Contaminated surfaces may contribute to transmission between patients.

Traditional environmental cleaning and disinfection remain important tools for infection control. Researchers have also investigated UV-C as a possible additional method for environmental decontamination.

Longer Exposure Produced Greater Reduction

In the study, researchers placed C. auris on glass surfaces and exposed the samples to UV-C radiation for different periods.

The researchers tested exposure times of 5, 10, 20 and 30 minutes at a distance of 2 meters, and also examined the effect of increasing the distance to 4 meters.

The strongest reduction was observed after 30 minutes of exposure at 2 meters.

The study also found that increasing the distance from 2 meters to 4 meters substantially reduced UV-C effectiveness. Higher concentrations of the organism also made complete reduction more difficult.

Distance Is Critical

According to the researchers, both exposure time and distance are critical factors when using UV-C for surface decontamination.

At suboptimal conditions, some C. auris strains were more resistant to UV-C than others. The researchers observed differences between strains originating from different geographic regions.

This means that simply placing a UV-C device in a room does not guarantee the same level of microbial reduction on every surface.

What This Means for Healthcare Facilities

The researchers concluded that UV-C may have potential as an adjunct to routine environmental cleaning, particularly when exposure time and distance are properly optimized.

However, the study was performed under controlled laboratory conditions. The authors emphasized the need for additional research to determine how UV-C performs in actual healthcare environments and whether its use can reduce C. auris transmission or healthcare-associated infections.

This Too LLC Perspective

The research highlights an important principle in environmental sanitation: technology works best when it is used according to the conditions under which it has been tested.

For UV-C systems, factors such as exposure time, distance, surface orientation, organism concentration, and equipment design can influence results.

UV-C should therefore be viewed as a potential supplement to established cleaning and disinfection procedures, rather than automatically replacing them.

Source: de Groot T, Chowdhary A, Meis JF, Voss A. Killing of Candida auris by UV-C: Importance of exposure time and distance. Mycoses. 2019;62:408–412.

This Too LLC News is an informational publication. The information above does not constitute medical advice or a recommendation to use UV-C equipment for healthcare decontamination.