Development of a novel bag-mediated filtration system for environmental recovery of poliovirus

Poliovirus (PV) is on the verge of global eradication. Due to asymptomatic shedding, eradication certification requires environmental and clinical surveillance. Current environmental surveillance methods involve collection and processing of 400-mL to 1-L grab samples by a two-phase separation method, where sample volume limits detection sensitivity. Filtration of larger sample volumes facilitates increased detection sensitivity. This study describes development of a pumpless in-field filtration system for poliovirus recovery from environmental waters. Recovery of PV types 1, 2, and 3 were compared for glass wool, ViroCap, and NanoCeram (PV1 only) filters. Seeded experiments were performed using 10⁵ plaque forming units of PV inoculated into 10-L volumes of secondary effluent, surface water, or a 50:50 mixture of each at pH 7.0. Filter eluates were plated onto buffalo green monkey kidney cells for virus enumeration by plaque assay. Across all water types, recovery from glass wool filters for PV1, PV2, and PV3 averaged 17%, 28%, and 6%, respectively. Recovery from ViroCaps for PV1, PV2, and PV3 averaged 44%, 70%, and 81%, respectively. 10-L samples of moderate turbidity water were processed through ViroCap filters in less than 30 minutes using a pumpless, bag-mediated filtration system. Bag-mediated filtration offers a simple, compact, and efficient method for enhanced environmental PV surveillance.