Q-277. Inactivation of Surrogate Coronaviruses on Hard Surfaces by Healthcare Disinfectants

R. L. Hulkower, L. M. Casanova, W. A. Rutala, D. J. Weber, M. D. Sobsey;
Univ. of North Carolina, Chapel Hill, NC.

The SARS coronavirus (SARS-CoV) was identified as the cause of severe acute respiratory syndrome (SARS) following the worldwide 2003 outbreak. The spread of SARS in healthcare settings and the presence of SARS CoV nucleic acids on hospital surfaces in outbreak settings suggest that surfaces could potentially play a role in the spread of SARS in healthcare environments. Disinfection of hospital surfaces may interrupt virus transmission, but there are little data on the effectiveness of disinfectants commonly used in healthcare against coronaviruses on surfaces. The goal of this research was to test the efficacy of four standard healthcare disinfectants for inactivation of surrogate coronaviruses on environmental surfaces. The disinfectants tested were (1) Steris Vesphene® IIse Non-sterile Disinfectant Cleaner (9.09% o-phenylphenol, 7.66% p-tertiary amylphenol), (2) 70% ethanol, (3) chlorine bleach (6.0% sodium hypochlorite), (4) Cidex® OPA (ortho-phthalaldehyde). These were tested for virucidal activity against two surrogate coronaviruses, Mouse Hepatitis Virus (MHV) and Transmissible Gastroenteritis Virus (TGEV). MHV and TGEV were dried onto stainless steel surfaces, exposed to a disinfectant at its use dilution for one minute contact time, and assayed for infectivity in cell culture. For TGEV, log10 infectivity reductions were: 70% ethanol = 3.2; phenolic = 3.2; Cidex OPA= 2.4; and 1:100 chlorine bleach = 0.26. For MHV, they were: 70% ethanol = 3.8; phenolic, = 1.2; Cidex OPA = 2.0; and 1:100 chlorine bleach = 0.52. Of the healthcare disinfectants tested, only 2, ethanol and a phenolic, effectively reduced infectivity of the two coronaviruses by >3 log10 after an exposure time of one minute. Cidex OPA was somewhat effective, with >2 log10 reduction, and 1:100 chlorine bleach was ineffective, with <1 log10 reduction. MHV and TGEV were reduced to a similar extent (within 0.5 log10) by the disinfectants tested. The results of this study suggest the need for care in choosing effective disinfectants against viruses like SARS CoV.