Inactivation of duck hepatitis B virus by a hydrogen peroxide gas plasma sterilization system: laboratory and 'in use' testing

Human hepatitis B virus (HBV) is an important cause of nosocomial infection s and can be transmitted by contaminated instruments. However, tests of the efficacy of sterilization of materials and equipment contaminated by HBV a re difficult to perform because the virus cannot be cultured in the laborat ory. In this study we aimed to evaluate the capability of a low temperature , hydrogen peroxide gas plasma sterilizer (Sterrad(R), Advanced Sterilizati on Products, Irvine California,) to inactivate duck hepatitis B virus (DHBV ). In laboratory efficacy studies using DHBV dried on to glass filter carri ers and exposed to one-half of the hydrogen peroxide gas plasma sterilizati on process, there was a 10(7) or greater decrease in the viral titer, with no infectivity detected on the carriers after treatment. In-use studies wer e performed using a laparoscope that was experimentally contaminated with D HBV to mimic the possible transmission of infection between successive pati ents. Following exposure to the hydrogen peroxide gas plasma sterilization process no transmission of DHBV infection from the laparoscope occurred des pite obvious visual soiling with blood (N=8) while the transmission rate fo r the unprocessed laparoscope (positive control) was 100% (26/26), and that for instruments after a water wash was 63% (7/11). In conclusion the hydro gen gas plasma sterilization process completely inactivates DHBV a represen tative of the hepadna group of viruses.