THE INACTIVATION KINETICS OF ECHOVIRUS 1 USING CHLORINE DIOXIDE AS A DISINFECTANT

Abstract

Laboratory experiments were performed to determine the kinetics of inactivation of ECHOvirus 1 (strain V239) by chlorine dioxide produced with the BIO-CIDE International, Inc. burst-pack product. Burst-pack reaction times for the production of chlorine dioxide were 15 minutes for test waters not pH adjusted (approximately 4.0) and 17 minutes for waters adjusted to pH 9.0 with borate buffer. Water quality types tested were tap, demand free, and worst case at 40 and 24°C. Additional experiments were conducted to determine chlorine dioxides mechanism of inactivation on poliovirus 1 (strain LSC). Polyacrylamide gel electrophoresis and slot blot analysis were used to follow changes in viral protein and RNA respectively when poliovirus 1 was exposed to 7.0 and 12.0 ppm chlorine dioxide. BIO-CIDE International, Inc. chlorine dioxide burst-packs were characterized to determine the practical efficacy of ARMY personnel use of the product for individual field drinking water disinfection. ECHOvirus 1 was inactivated relatively rapidly by chlorine dioxide under all conditions tested, with times for a 4 log (99.99%) inactivation within 10 minutes. Virus inactivation by chlorine dioxide was more effective at 240C than at 4°C for waters with unadjusted pH. Virus inactivation in waters adjusted to pH 9.0 were equal at 24°C and 40C. In general, inactivation was more effective at the high pH and temperature level than at the low levels. Chlorine dioxide produced changes in viral protein and RNA in poliovirus 1 treated with 7.0 and 12.0 ppm disinfectant. Since reaction at both the protein and RNA level occurred, inactivation may be due to their collective damage. Further research with respect to this is needed to say for certain. The burst-pack chlorine dioxide product is relatively easy to use. But modifications in the design of the package are needed to improve the reproducibility of disinfectant production between different individuals as well as from pack to pack.