Comparison of bioaerosol collection methods in the detection of airborne influenza virus

The World Health Organization estimates annual influenza epidemics could generate up to 5 million cases of severe illness and 500,000 deaths worldwide. Few researchers have been successful in determining personal exposures to influenza viruses through the airborne route with samplers that are currently available. Therefore, new sampling strategies should be considered.

This study compared four samplers in the collection of airborne influenza virus – the SKC Biosampler, NIOSH Biosampler, Andersen N6 single-stage impactor containing a liquid media, and the newly developed NGIAS sampler. Ten 30-minute trials were completed by aerosolizing influenza virus (H1N1) in a laboratory chamber.

Analyses determined the NGIAS recovered significantly less viral particles per liter of sampled air (TVP) than all other samplers (p-value < 0.001). The TVP recovered by both liquid based samplers (SKC and Andersen N6) was substantially larger than that recovered by both dry collection based samplers (NIOSH and NGIAS). The high flow rate sampler, the Andersen N6, did not collect more TVP, but had a lower limit of detection than other samplers. Therefore, the Andersen N6 sampler may be more efficient at detecting influenza viruses in settings where virus concentrations are lower (hospitals, schools, daycares, etc.). Furthermore, the SKC Biosampler collected the most TVP. Future research should consider designing a liquid based personal sampler that operates at a high airflow rate to increase the probability of influenza virus detection.