Development and evaluation of electrostatic aerosol-to-hydrosol sampler for single-pass airborne influenza virus sampling

Effective control measures are needed to combat airborne (aerosol) viruses present in human respiratory droplets. To assess virus inactivation, an aerosol sampler capable of collecting viruses while preserving their infectivity is required. This study developed a rotating electrostatic aerosol-to-hydrosol sampler (REAHS) with a low pressure drop and concentrated sampling. To minimize the loss of infectious viruses due to ozone generated during electrostatic collection, a new electrode was designed to suppress ozone production while maintaining collection efficiency. The electrode has a two-step central diameter, reducing the corona discharge area while ensuring the high electric field strength required for collection. Tests using simulated viral particles confirmed a collection efficiency greater than 80% for submicron particles (25–660 nm) while maintaining the ozone concentration at 0.076 parts per million. In addition, experiments with infectious influenza viruses demonstrated that the system collected viruses at concentrations 13.3 times higher than those of a gelatin filter while preserving infectivity. These findings suggest that the REAHS is a suitable sampler for additional studies on the efficacy of airborne virus inactivation.