On the Influence of the Risk of Virus Infections by Heat Sanitization of the PHD Hemodialysis Equipment

Virus infections, particularly the hepatitis viruses and HIV are constant threats to dialysis patients. There are no studies of the influence of heat sanitization of dialysis equipment. When multiple patients use a dialysis machine, the possibility of human blood-borne virus transmission exists. To assure the safety of the PHD we studied inactivation of several logs of viral infectivity, by the PHD disinfection process. Methods: Heated RO water was spiked with model viruses at 75°C ± 1°C and 82°C ± 2°C for 0, 20 and 45 minutes. As model viruses we used bovine viral diarrhea virus (BVDV)Ñ model for hepatitis C, hepatitis A virus (HAV), and porcine parvovirus (PPV). PPV is very robust and resistant to heat sanitaization procedures and served as the model for Hep-B and HIV that cannot be used in vitro studies. Results: 75C treatment instantaneously reduced the BVDVviral titer to non-detectable levels. HAV, one of the most robust viruses evaluated in viral clearance studies, was also reduced to non-detectable levels within 20 minutes. The PPV titer was reduced by approximately 5 log10 within 45 minutes. At 82°C ± 2°C, PPV was reduced to non-detectable levels within 20 minutes. Given that parvoviruses are the most robust viruses evaluated to date in viral clearance studies, the true potential of the treatment step to inactivate viruses is much greater than can be demonstrated. Conclusions: The heat treatment used by the PHD is very “robust”. Given that this study was performed at reduced temperature and time and that the typical PHD System disinfection temperature is 85°C ± 5°C for 1 hour, the convincing log10 reduction values for PPV not only demonstrate the safety of the PHD heat sanitization presently, but also provide a strong indication that the treatment will also inactivate other currently unknown viruses.