Study of the temperature sensitivity of severe fever with thrombocytopenia syndrome virus

ABSTRACT

This study investigated the temperature sensitivity of severe fever with thrombocytopenia syndrome virus (SFTSV) to provide a basis for SFTSV disinfection and laboratory biosafety protection. We divided SFTSV cell culture supernatants into 250 L PCR vials at 100 L/tube, and placed them in a refrigerator at 4..C, and a metal bath at 25..C, 37..C, 39..C, 56..C, and 70..C. After treatment for predetermined periods of time, the viral titer was determined through indirect immunofluorescence in Vero cells. With increasing temperature, the rate of decline of the viral titer increased. After incubation at 4..C, 25..C, 37..C, and 39..C for 24 h, the titers decreased from 107.25/100 L to 107.00/100 L, 106.75/100 L, 106.50/100 L, and 105.00/100 L, respectively. At the same temperature, with prolonged storage time, the decrease in titer became more pronounced. After SFTSV was placed at 4..C, 25..C, 37..C for 72 h, the viral titer decreased from 107.25/100 L to 106.63/100 L, 106.50/100 L, and 103.38/100 L, respectively. SFTSV lost its infectivity after incubation at 39..C for 72 h. SFTSV was inactivated after exposure to 56..C for 180 min or 70..C for 5 min. We concluded that SFTSV is inactivated after incubation at 70..C for 5 min. However, after 3 days of exposure to 4..C and 25..C, the viral titer did not change significantly. Laboratories and medical staff should focus on personal protection and disinfection of items contaminated by SFTSV.