Efficacy of Ultraviolet Irradiation in Controlling the Spread of Tuberculosis, October 14, 2002

摘要

The efficacy of killing or inactivating airborne bacteria using upper-room air UVGI from a modern UVGI system was investigated in realistic physical scenarios under carefully controlled laboratory conditions. The research objectives pursued in this project are detailed: (1) Establishment of a full-scale test room that simulated a typical health-care facility isolation room with a modern UVGI system; (2) Characterize the irradiance provided to the test room by the UVGI system; (3) Estimate the effectiveness of UVGI for three microorganisms (Mycobacterium parafortuitum, Bacillus subtilis spores, and Mycobacterium bovis BCG) for two room ventilation rates, 0 and 6 air changes per hour; Measure the inactivation rate as a function of UVGI and calculate the Z value due to UVGI for M. parafortiuitum; (5) Evaluate the impact of varying relative humidity on the UVGI effectiveness and inactivation rate; (6) Quantify how different levels, and spatial distributions, of UVGI, impact the inactivation rate; (7) Determine whether photoreactivation is a concern for real applications of UVGI; (8) Establish whether the air mixing in a room will change the performance of a UVGI system.