ABSTRACT
Background: Emerging and re-emerging infections caused by viruses continue to threaten us. Over the past decades, Singapore has faced threats caused by the SARS Coronavirus, Influenza, Dengue, and Chikungunya viruses, just to name a few. To understand the viral pathogenicity as well as control and prevention of the infections, a high containment has been applied for the research of high biorisk pathogens. Here, a standard precaution has been established to remove an inactivated virus samples to low biosafety environment as a business continuous strategy. An inactivate protocol is divided into two parts, inactivation and validation. Inactivation is a strategy completely remove the virus infectivity, included physical and chemical methods, e.g. heat and methanol. Validation shall be a solid method to reveal inactivation part was sufficient to inactivate virus and the samples still able to carry out for downstream experiments. Methods and materials: Stability of virus was performed in different temperatures. The virus cultures were aliquot into 200 uL and incubated from 5 mins up to 2 weeks in -80 °C, 4 °C, room temperature, 37 °C, and 95 °C. Cell lines infected by virus was fixed by 100% cold methanol for 15 mins, then washed and harvested for validation. To extract viral genome, an infected cells or virus cultures was treated by lysis buffer containing guanidine isothiocyanate. All treated samples were used to cultivate for at least 3 days to validate it has no virus CPE. For safety precaution, a witness is required to monitor the inactivation process. Results: By an in-principle approval protocol, the Mayaro virus (MAYV), for example, was certified to inactivate by using 95 °C for 5 mins, 100% cold methanol for 15 mins, and lysis buffer containing guanidine isothiocyanate for 5 mins. However, the infectivity of MAYV was started dropping after 24 hrs in 37 °C and 7 days in room temperature. It was no infectivity after 72 hrs in 37 °C. Conclusion: In conclusion, to remove a high biorisk samples to low biosafety environment for downstream experiments may expose to the risk and to cause laboratory-acquired infections. A proper guideline, procedure, and training shall be in place for prevention and control.