Inactivation of SARS coronavirus by means of povidone-iodine, physical conditions, and chemical reagents.

Kariwa, Hiroaki; Fujii, Nobuhiro; Takashima, Ikuo

The efficacy of several povidone-iodine (PVP-I) products, a number of other chemical agents, and various physical conditions were evaluated for their ability to inactivate the severe acute respiratory syndrome coronavirus (SARS-CoV). Treatment of SARS-CoV with PVP-I products for 2 min reduced the virus infectivity from 1.17 x 10(6) TCID50/ml to below the detectable level. The efficacy of 70% ethanol was equivalent to that of PVP-I products. Fixation of SARS-CoV-infected Vero E6 cells with a fixative including formalin, glutaraldehyde, methanol, and acetone for 5 min or longer eliminated all infectivity. Heating the virus at 56 degrees C for 5 min dramatically reduced the infectivity of the virus from 2.6 x 10(7) to 40 TCID50/ml, whereas heating the virus for 60 min or longer eliminated all infectivity. Irradiation with ultraviolet light at 134 microW/cm2 for 15 min reduced the infectivity from 3.8 x 10(7) to 180 TCID50/ml; however, prolonged irradiation (60 min) failed to eliminate the remaining virus, leaving 18.8 TCID50/ml. We believe that these findings will be useful for the implementation of infection control measures against SARS, and for the establishment of effective guidelines for the prevention of SARS outbreaks.