Non-equilibrium plasma prevention of Schistosoma japonicum transmission.

Xing-Quan Wang,Jun Huang,Kateryna Bazaka,Kostya Ostrikov,Wei Chen,Feng-Peng Wang

doi:10.1038/srep35353

Abstract

Schistosoma japonicum is a widespread human and animal parasite that causes intestinal and hepatosplenic schistosomiasis linked to colon, liver and bladder cancers, and anemia. Estimated 230 million people are currently infected with Schistosoma spp, with 779 million people at risk of contracting the parasite. Infection occurs when a host comes into contact with cercariae, a planktonic larval stage of the parasite, and can be prevented by inactivating the larvae, commonly by chemical treatment. We investigated the use of physical non-equilibrium plasma generated at atmospheric pressure using custom-made dielectric barrier discharge reactor to kill S. japonicum cercariae. Survival rate decreased with treatment time and applied power. Plasmas generated in O2 and air gas discharges were more effective in killing S. japonicum cercariae than that generated in He, which is directly related to the mechanism by which cercariae are inactivated. Reactive oxygen species, such as O atoms, abundant in O2 plasma and NO in air plasma play a major role in killing of S. japonicum cercariae via oxidation mechanisms. Similar level of efficacy is also shown for a gliding arc discharge plasma jet generated in ambient air, a system that may be more appropriate for scale-up and integration into existing water treatment processes.

Highlights

Schistosomiasis is a significant parasitic disease cause by members of Schistosoma spp
Given the killing efficiency and the intensity of O lines in He and O2 discharges, these results suggest that in the case of oxygen plasma treatment, O atoms play a major role in killing S. japonicum cercariae
We investigated whether similar level of killing efficacy could be achieved using a different plasma reactor, a gliding arc discharge (GAD) plasma jet generated in ambient air, since this system that may be more appropriate for scale-up and integration into existing water treatment processes compared to dielectric barrier discharge (DBD), which may be restricted by the gap width

Summary

Introduction

Schistosomiasis is a significant parasitic disease cause by members of Schistosoma spp. We investigated survival curves of S. japonicum cercariae after treatment with plasma as a function of the gas type and applied power used to generate plasma, namely He, O2 and air gas discharges, and as a function of treatment duration.

Results

Conclusion