Inactivation of a hepadnavirus by electrolysed acid water

Abstract

Glutaraldehyde is used as a disinfectant for endoscopes, but is an irritant and so should be replaced by an alternative. Electrolysed acid water (EAW) has a bactericidal effect, and an endoscopic washing device using EAW has been developed in Japan. To investigate the effect of EAW on the infectivity of viruses, we treated duck hepatitis B virus (DHBV), which has similar properties to hepatitis B virus, with EAW, and determined the number of remaining infectious virus particles in a bioassay system. One-day-old Pekin ducks were inoculated with duck serum containing 10(5.5) ID(50) DHBV; the serum had previously been incubated with 100 volumes of EAW or ion-exchanged water at room temperature for 7 min. DHBV infection was indicated by detection of viral DNA in duck serum samples 1-8 weeks after inoculation. Treatment of serum with EAW diminished DHBV infectivity whereas treatment with ion-exchanged water did not. The virus load was estimated to have been reduced to 10(1)-10(3) ID(50) during the first 1 min and to <10(0.5) ID(50) in the next 6 min of incubation when compared with the control. Thus, EAW directly inactivates DHBV and its clinical application is recommended.

Electrochemically activated solutions: evidence for antimicrobial efficacy and applications in healthcare environments

“…An immunoassay has been used to assess ECAS a -treated hepatitis B virus (HBV) surface antigen (in the absence of an appropriate whole-cell bioassay) and a significant concentrationdependent reduction in the measured antigenicity was observed [93]. The authors postulated that this was indicative of a reduction in the infectivity of human HBV [93] and this is supported by the finding that ECAS a reduced the infectivity of a hepatitis B surrogate, duck hepatitis B virus, indicating the efficacy of ECAS a against hepadnaviruses [92]. Similarly, the ECAS a treatment of the norovirus surrogate bacteriophage MS2 was shown to significantly reduce infectivity, although significantly longer exposure times were required for surface-associated virions, presumably due to reduced accessibility of the active moieties [94].…”

“…Numerous studies have demonstrated the virucidal activity of ECAS a against a broad range of targets [48, 51, 61, [92][93][94][95][96][97], comparable to that of other biocidal agents [92]. Most methodologies expose virus particles in suspension to ECAS a in the presence/absence of organic loading, whereby ECAS a reduces the number of viable virus particles as measured by cytopathic effects of the target virions in subsequently infected cell lines [48,51].…”

“…Fogged ECAS a has been found to significantly reduce the surface levels of both human norovirus and surrogate viruses, as detected by reverse transcriptase polymerase chain reaction [94], and both acidic and neutralised ECAS a have shown significant activity against human immunodeficiency virus (HIV), even when infectious particles are pre-adsorbed onto an inanimate surface [61,95]. Since viruses do not have cell walls, it has been postulated that the mode of action is likely to be the inactivation of surface protein, destruction of the viral envelope, inactivation of viral enzymes or the destruction of viral nucleic acid [92,93], collectively eradicating their potential infectivity. In support of this theory, at least some ECAS a components have been shown to penetrate the viral envelope [93].…”

<b>Disinfection potential of electrolyzed strongly acidic water against </b><i><b>Mycobacteria</b></i><b>: Conditions of disinfection and recovery of disinfection potential by reelectr</b><b>olysis </b>

“…Electrolyzed strongly acidic water (ESW) has been widely used for infection control in clinical settings (7,9) because it has been proved to be effective for the disinfection of disinfectant-resistant bacteria, such as Mycobacteria (15), Pseudomonas aeruginosa (6), and spore-forming bacteria (3,4,6), and viruses causing blood-borne infections such as hepatitis B virus (8,11) and HIV (5). ESW is also expected to be used against pathogens of emerging diseases, such as the avian influenza virus H5N1 (12).…”

“…High-level disinfectants, such as glutaraldehyde (GA), have disinfection potentials against any microorganisms; however, it has been reported that it may be harmful to patients and healthcare workers (1,2). ESW is considered less toxic than GA (13), and it has been reported to be effective against disinfectantresistant bacteria, such as Pseudomonas aeruginosa (6), spore-forming bacteria (3,4,6), and bloodborne infectious pathogens such as hepatitis B virus (8,11) and HIV (5) depending on the condition. Further study is needed to clarify both the disinfection spectrum of ESW and the optimum conditions for disinfection, particularly the relationship between smaller apparatus with the positive electrode and then re-electrolyzed at a constant voltage of 24 V for 7 min.…”