Comparison of Zika Virus Inactivation Methods for Reagent Production and Disinfection Methods.

Abstract Zika virus (ZIKV) infection remains a public health concern necessitating demand for long-term virus production for diagnostic assays and RD 2. Gamma-Irradiation; 3. Chemical inactivation by Beta-propiolactone (BPL) and 4. Fast-acting commercial disinfecting agents. Effectivity was measured by cytopathic effect (CPE) and plaque assay. RNA stability and antigenicity were measured by RT-PCR and MAC-ELISA, respectively. Results: Heat inactivation: Low titer samples, incubated at 56 °C for 2 hrs, showed neither CPE or plaques compared to high titer supernatants that required 2.5 hrs. Inactivation occurred at 60 °C for 60 min with all virus titers. Gamma irradiation: Samples irradiated at ≥3 Mrad for low virus concentrations and ≥5Mrad for high virus titer completely inactivated virus. Chemical Inactivation: Neither CPE nor plaques were observed with ≥0.045% BPL inactivation of ZIKV. Disinfectant: Treatment of viral supernatants with Micro-Chem PlusTM, inactivated virus in 2 min, whereas, Ethanol (70%) and STERIS Coverage® Spray TB inactivated the virus in 5 min.