Validation of the bag‐mediated filtration system for environmental surveillance of poliovirus in Nairobi, Kenya

• DOI: 10.1111/jam.14807
• Publication Date: 2020-08-03T01:00:20Z
• Authors: C.S. Fagnant‐Sperati; Y. Ren; N.A. Zhou; E. Komen; B. Mwangi; J. Hassan; A. Chepkurui; R. Nzunza; J. Nyangao; W.B. Zyl; M. Wolfaardt; P.N. Matsapola; F.B. Ngwana; S. Jeffries‐Miles; A. Coulliette‐Sal...; S. Peñaranda; E. Vega; J.H. Shirai; A.L. Kossik; N.K. Beck; D.S. Boyle; C.C. Burns; M.B. Taylor; P. Borus; J.S. Meschke
• Keywords: 0301 basic medicine; Sewage; Enteric viruses; ViroCap; Original Articles; Wastewater; Serogroup; Bag-mediated filtration system (BMFS); Kenya; 3. Good health; Poliovirus; 03 medical and health sciences; Standard WHO two‐phase separation methods; Poliovirus Vaccine, Oral; Humans; Environmental surveillance; Filtration; Environmental Monitoring; Poliomyelitis

This study compared the bag-mediated filtration system (BMFS) and standard WHO two-phase separation methods for poliovirus (PV) environmental surveillance, examined factors impacting PV detection and monitored Sabin-like (SL) PV type 2 presence with withdrawal of oral polio vaccine type 2 (OPV2) in April 2016.Environmental samples were collected in Nairobi, Kenya (Sept 2015-Feb 2017), concentrated via BMFS and two-phase separation methods, then assayed using the WHO PV isolation algorithm and intratypic differentiation diagnostic screening kit. SL1, SL2 and SL3 were detected at higher rates in BMFS than two-phase samples (P < 0·05). In BMFS samples, SL PV detection did not significantly differ with volume filtered, filtration time or filter shipment time (P > 0·05), while SL3 was detected less frequently with higher shipment temperatures (P = 0·027). SL2 was detected more frequently before OPV2 withdrawal in BMFS and two-phase samples (P < 1 × 10-5 ).Poliovirus was detected at higher rates with the BMFS, a method that includes a secondary concentration step, than using the standard WHO two-phase method. SL2 disappearance from the environment was commensurate with OPV2 withdrawal.The BMFS offers comparable or improved PV detection under the conditions in this study, relative to the two-phase method.