First data on stability and resistance of SARS coronavirus compiled by members of WHO laboratory network

The below table provides the first compilation of data on resistance of the SARS Coronavirus against environmental factors and disinfectants. This information has been provided by Members of the WHO multi-center collaborative network on SARS diagnosis. More detailed information on methods utilized and material used is being compiled and will be available shortly. The major conclusions from these studies are:

Virus survival in stool and urine

• Virus is stable in faeces(and urine) at room temperature for at least 1-2 days.
• Virus is more stable (up to 4 days) in stool from diarrhea patients (which has higher pH than normal stool).

Disinfectants


• Virus loses infectivity after exposure to different commonly used disinfectants and fixatives.

Virus survival in cell-culture supernatant


• Only minimal reduction in virus concentration after 21 days at 4°C and -80°C.
• Reduction in virus concentration by one log only at stable room temperature for 2 days. This would indicate that the virus is more stable than the known human coronaviruses under these conditions.
• Heat at 56°C kills the SARS coronavirus at around 10000 units per 15 min (quick reduction).

Fixatives (for use in laboratories only)



• SARS virus fixation (killing) on glass slides for immunofluorescence assays in room temperature does not kill virus efficiently unless the acetone is cooled down to -20oC.

  Lab*	Substrate	Initial viral count log10PFU	Condition	Survival time		Method of testing viability
  GVU	virus spiked in baby stool	1.00E+03	pH 6-7	3 hr		Virus isolation in cell culture
  	virus spiked in normal stool	7.50E+03	pH 8	6hr		Virus isolation in cell culture
  	virus in diarrheal stool	7.50E+03	pH 9	4days		Virus isolation in cell culture
  QMH	stool	1.00E+03	Room Temperature	at least 2 days		Virus isolation in cell culture
  	urine	1.00E+03	Room Temperature	at least 24 hr		Virus isolation in cell culture
  	Virus culture medium+ 1% bovine serum	1.00E+03	on plastic surface in room temperature	at least 2 days		Virus isolation in cell culture
  	Virus culture medium+ 1% bovine serum	1.00E+04	30-37°C	at least 1hr		Virus isolation in cell culture
  	Virus culture medium+ 1% fetal calf serum	1.00E+04	56°C	degration of titre over time (10 000 infectious virus units in 15 min)		Virus isolation in cell culture
  	virus in Acetone, 10% Formaldehyde and Paraformaldehyde, 10% Clorox, 75%ethanol, 2% phenol	1.00E+06	Room Temperature	less than 5 min		Virus isolation in cell culture
  NIID	Virus culture+ 2% bovine serum	1.00E+06	minus 80°C	at least 4 days		Virus isolation and RT-PCR
  	Virus culture+ 2% fetal calf serum	1.00E+06	4°C	at least 4 days		Virus isolation and RT-PCR
  	Virus culture+ 2% fetal calf serum	1.00E+06	37°C	less than 4 days		Virus isolation and RT-PCR
  	Virus culture+ 2% fetal calf serum	1.00E+05	56°C	less than 30min
  UniM	Virus culture	1.00E+06	4°C	at least 21 days		Virus isolation
  	Virus culture	1.00E+06	minus 80°C	at least 21 days		Virus isolation
  CUHK	Virus in phosphate buffered saline (PBS) Virus in sterilized stool	9.00E+04	Room Temperature on	PBS	Stool	Virus isolation in cell culture
  			plastered wall	24h	36h
  			plastic surface	36h	72h
  			formica surface	36h	36h
  			stainless steel	36h	72h
  			wood	12h	24h
  			cotton cloth	12h	24h
  			pig skin	≥24h	≥24h
  			glass slide	72h	96h
  			paper file cover	24h	36h

  CUHK Chinese University Hong Kong
  GVU: Government Virus Unit, Dept. of Health, Hong Kong, SAR China
  QMH: Queen Mary Hospital, The University of Hong Kong, Hong Kong, SAR China
  NIID: National Institute of infectious Diseases, Tokyo, Japan
  UnivM: University Marburg, Germany