Assessment of the risks posed by severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV) on surfaces requires data on survival of this virus on environmental surfaces and on how survival is affected by environmental variables, such as air temperature (AT) and relative humidity (RH).
The use of surrogate viruses has the potential to overcome the challenges of working with SARS-CoV and to increase the available data on coronavirus survival on surfaces. Two potential surrogates were evaluated in this study; transmissible gastroenteritis virus (TGEV) and mouse hepatitis virus (MHV) were used to determine effects of AT and RH on the survival of coronaviruses on stainless steel.
At 4°C, infectious virus persisted for as long as 28 days, and the lowest level of inactivation occurred at 20% RH. Inactivation was more rapid at 20°C than at 4°C at all humidity levels; the viruses persisted for 5 to 28 days, and the slowest inactivation occurred at low RH. Both viruses were inactivated more rapidly at 40°C than at 20°C. The relationship between inactivation and RH was not monotonic, and there was greater survival or a greater protective effect at low RH (20%) and high RH (80%) than at moderate RH (50%). There was also evidence of an interaction between AT and RH. The results show that when high numbers of viruses are deposited, TGEV and MHV may survive for days on surfaces at ATs and RHs typical of indoor environments. TGEV and MHV could serve as conservative surrogates for modeling exposure, the risk of transmission, and control measures for pathogenic enveloped viruses, such as SARS-CoV and influenza virus, on health care surfaces.
Applied and Environmental Microbiology, May 2010, p. 2712-2717, Vol. 76, No. 9 0099-2240/10/$12.00+0 doi:10.1128/AEM.02291-09
Lisa M. Casanova -1*
Soyoung Jeon – 2
William A. Rutala – 3
David J. Weber – 3
Mark D. Sobsey – 1
1 – Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
2 – Department of Statistics and Operations Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
3 – Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
* Corresponding author. Mailing address: CB# 7431 McGavran-Greenberg Hall, Room 3206, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599. E-mail: [email protected] Phone: (919) 966-7317. Fax: (919) 966-7911.
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