A new study has demonstrated the effectiveness of ultraviolet light (UV-C) in inactivating Mycobacterium abscessus (MABS), which can cause infection in people with cystic fibrosis (CF).

The study, published in the Journal of Hospital Infection, found doses ranging from 276 to 1104 μW s/cm2 were all effective doses in terms of MABS inactivation.

“Ultraviolet light in band C (UV-C, wavelength 200-280 nm) has well-known microbicidal properties that inactivate or kill airborne microbes, and UV-C has been used for airborne Mycobacterium tuberculosis infection control indoors since the 1950s,” the authors wrote. “We aimed to: (1) determine if UV-C leads to a greater reduction in airborne MABS than in the absence of UV-C, and (2) quantify the relationship between UV-C dose and airborne MABS survival under controlled conditions.”

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The research team generated MABS using a 400-L rotating drum sampler with a vibrating mesh nebulizer inside. They then used a UV-C light-emitting diode array to test the ability of a range of UV-C doses to inactivate MABS over a period of 20 minutes, comparing the difference in inactivation levels with and without UV-C.

The authors performed 16 tests, using an indoor hospital environment model and UV-C doses from 276 to 1104 μW s/cm2. An Andersen Cascade Impactor to collect aerosols was used to compare MABS levels before and after dosing with UV-C.

The results showed that all doses of UV-C were effective at inactivating MABS, with a range of effectiveness between 47.1% and 83.6%. Furthermore, the doses used appeared to be safe for use in indoor clinical settings, without posing risks to staff or to patients.

As the next step, the authors recommend further studies to assess the ability of UV-C to inactivate human-generated MABS from patients with CF and other lung diseases.  

Reference

Nguyen T, He C, Carter R. Quantifying the effectiveness of ultraviolet-C (UV-C) light at inactivating airborne Mycobacterium abscessus. J Hosp Infect. Published online October 26, 2022. doi:10.1016/j.jhin.2022.10.008