title: Inactivation of enteric adenovirus and feline calicivirus by chlorine dioxide.
abstract: Chlorine dioxide (ClO2) inactivation experiments were conducted with adenovirus type 40 (AD40) and feline calicivirus (FCV). Experiments were carried out in buffered, disinfectant demand-free water under high- and low-pH and -temperature conditions. Ct values (the concentration of ClO2 multiplied by contact time with the virus) were calculated directly from bench-scale experiments and from application of the efficiency factor Hom (EFH) model. AD40 Ct ranges for 4-log inactivation (Ct99.99%) at 5 degrees C were >0.77 to <1.53 mg/liter x min and >0.80 to <1.59 mg/liter x min for pH 6 and 8, respectively. For 15 degrees C AD40 experiments, >0.49 to <0.74 mg/liter x min and <0.12 mg/liter x min Ct99.99% ranges were observed for pH 6 and 8, respectively. FCV Ct99.99% ranges for 5 degrees C experiments were >20.20 to <30.30 mg/liter x min and >0.68 mg/liter x min for pH 6 and 8, respectively. For 15 degrees C FCV experiments, Ct99.99% ranges were >4.20 to <6.72 and <0.18 mg/liter x min for pH 6 and 8, respectively. Viral inactivation was higher at pH 8 than at pH 6 and at 15 degrees C than at 5 degrees C. Comparison of Ct values and inactivation curves demonstrated that the EFH model described bench-scale experiment data very well. Observed bench-scale Ct99.99% ranges and EFH model Ct99.99% values demonstrated that FCV is more resistant to ClO2 than AD40 for the conditions studied. U.S. Environmental Protection Agency guidance manual Ct99.99% values are higher than Ct99.99% values calculated from bench-scale experiments and from EFH model application.
authors.affiliation: US Department of Agriculture-Agricultural Research Service, 120 Keim Hall, University of Nebraska East Campus, Lincoln, Nebraska 68583-0934, USA. Jthurston2@unl.edu
authors.forename: Jeanette A
authors.initials: JA
authors.lastname: Thurston-Enriquez
authors.forename: Charles N
authors.initials: CN
authors.lastname: Haas
authors.forename: Joseph
authors.initials: J
authors.lastname: Jacangelo
authors.forename: Charles P
authors.initials: CP
authors.lastname: Gerba
mesh_terms: D000260:Adenoviruses, Human / Q000187:drug effects*; D000818:Animals; D017927:Calicivirus, Feline / Q000187:drug effects*; D002415:Cats; D002460:Cell Line; D017606:Chlorine Compounds / Q000494:pharmacology*; D004203:Disinfection / Q000379:methods* / Q000592:standards; D005618:Fresh Water / Q000821:virology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D010087:Oxides / Q000494:pharmacology*; D013696:Temperature; D038301:Virus Inactivation
chemical_list: D017606:Chlorine Compounds; D010087:Oxides; C025109:chlorine dioxide