Bacteriophage Phi X-174 As an Aerobiological Marker for Surgical Plume Generated by the Electromagnetic Field Focusing System

The aerosol of surgical plume could be measured effectively with the use of bacteriophage phi X-174 as a biological marker, in contrast to previous methodologies reported by others. Recovery of virus plaque-forming units was highest from hydrophobic polytetrafluoro-ethylene membranes compared to hydrophobic polycarbonate screen filters or polyvinylidene difluoride depth filters, indicating that the method of virus recovery strongly affects the utility of a virus as an aerobiological marker. With this new method, surgical plume was indeed found in significant amounts when cutting tissue phantoms made with agar containing virus. The Electromagnetic Field Focusing System was used, which is a new thermal surgical device. The nominal power setting did not appear to be a factor in the amount of virus recovered. However, when pulse modulating the power by adjusting the crest factor from 1.4 to 4.3, a measure of the duty cycle for power delivery which adjusted the device from its cutting to haemostatic mode, a nearly five-fold increase in surgical plume, as evidence by the recovery of phi X-174 plaque forming units, was seen. The data indicate that bacteriophage phi X-174 can be used effectively as an aerobiological marker for aerosols generated during clinical procedures, and reinforce the need to use a safety vacuum during aerosol generating procedures. The availability of a safe and economical biological marker for aerosols from clinical procedures, which may lead to acquired infections in hospital personnel, makes evaluation of procedures and containment systems markedly easier. The data also indicates that surgical plume biohazard may be present in other techniques that employ pulse modulation including surgical lasers and electrocauteries.