Background levels of viable bacteria and fungi in the indoor air and on surfaces in Ingham Regional Medical Center “before and after” the UVGI-HVAC installation.

The objective of this project was to assess microbial concentrations in air and on fomites in Ingham Hospitals before and after the installation of a UVGI-HVAC system. Using bacteria and fungi concentrations as a standard of effectiveness of the UVGI-HVAC system, indoor air samples were collected before and after installation and microbial levels were compared. Using the impingement method as described by Jensen and Schafer (1998) viable microorganisms (E. coli, total bacteria, Staphylococci, MRSA, and fungi) were sampled in the air. This study also investigated indoor surface contamination because fomites have been shown to act as reservoirs for spreading diseases (Morens, D. M., and V. M. Rash. 1995; Bures et al. 2000; Barker, J. 2001; Barker et al. 2004; Kramer et al. 2006; Boone and Gerba 2005). Preliminary samples were collected in the summer of 2007 and post UVGI installation samples were collected in the fall of 2008. Both pre/post installation samples were collected in the emergency department waiting room and cardiac intensive care unit of the Greenlawn Campus and in the UCC waiting room and patient room in 1E at the Pennsylvania Campus.