Detection of potentially pathogenic enteric viruses in environmental samples from Kenya using the bag-mediated filtration system

Enteric virus environmental surveillance via a highly sensitive method is critical, as many enteric viruses have low infectious doses and can persist in the environment for extended periods. This study determined the potential of the novel bag-mediated filtration system (BMFS) to recover human enteric viruses and pepper mild mottle virus (PMMoV) from wastewater and wastewater-impacted surface waters, examined PMMoV use as a fecal contamination indicator in Kenya, and identified potential BMFS process controls. From April 2015 to April 2016, BMFS samples were collected from seven sites in Kenya (n = 59). Enteroviruses and PMMoV were detected in 100% of samples, and human adenovirus, human astrovirus, hepatitis A virus, norovirus GI, norovirus GII, sapovirus, and human rotavirus were detected in the majority of samples. The consistent detection of enteroviruses and PMMoV suggests that these viruses could be used as indicators in similarly fecally contaminated sites and BMFS process controls. As contamination of surface water sources remains a global issue, enteric virus environmental surveillance is necessary. This study demonstrates an effective way to sample large volumes of wastewater and wastewater-impacted surface waters for the detection of multiple enteric viruses simultaneously.The Paul G. Allen Family Foundation (NPT.1938-603689), with management by the Bill and Melinda Gates Foundation, the UW NIEHS sponsored Biostatistics, Epidemiologic and Bioinformatic Training in Environmental Health (BEBTEH) Training Grant (NIEHS T32ES015459) and the National Science Foundation (OCE-1566562).http://wst.iwaponline.comhj2019Medical Virolog

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

AIMS : 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. METHODS AND RESULTS : 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 9 10 5). CONCLUSIONS : 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. SIGNIFICANCE AND IMPACT OF THE STUDY : The BMFS offers comparable or improved PV detection under the conditions in this study, relative to the twophase method.SUPPORTING INFORMATION: Appendix S1. Nairobi environmental surveillance sites. Appendix S2. Statistical methods. Appendix S3. Replicate BMFS samples. Appendix S4. Samples included in statistical analyses. Appendix S5. NPEV detection in BMFS and two‐phase samples.Funding was provided by the Paul G. Allen Foundation, Grant Number NPT.1938-603689, and the Bill and Melinda Gates Foundation, Grant Number OPP1170548. This work was supported in part by the UW NIEHS sponsored Biostatistics, Epidemiologic and Bioinformatic Training in Environmental Health (BEBTEH) Training Grant, Grant #: NIEHS T32ES015459. We would like to thank James Angawa, Public Health Surveillance Officer, Nairobi County and Pius Odhiambo, Community Health Volunteer, for their assistance sampling; Director of KEMRI for facilitating the study; Graciela Matrajt for her technical writing assistance; and Dan Phillips for his assistance with project coordination.The Paul G. Allen Foundation and the Bill and Melinda Gates Foundation.https://sfamjournals.onlinelibrary.wiley.com/journal/13652672am2020Medical Virolog

Feasibility of the bag-mediated filtration system for environmental surveillance of poliovirus in Kenya

The bag-mediated filtration system (BMFS) was developed to facilitate poliovirus (PV) environmental surveillance, a supplement to acute flaccid paralysis surveillance in PV eradication efforts. From April to September 2015, environmental samples were collected from four sites in Nairobi, Kenya, and processed using two collection/concentration methodologies: BMFS (> 3 L filtered) and grab sample (1 L collected; 0.5 L concentrated) with two-phase separation. BMFS and two-phase samples were analyzed for PV by the standard World Health Organization poliovirus isolation algorithm followed by intratypic differentiation. BMFS samples were also analyzed by a cell culture independent real-time reverse transcription polymerase chain reaction (rRT-PCR) and an alternative cell culture method (integrated cell culture-rRT-PCR with PLC/PRF/5, L20B, and BGM cell lines). Sabin polioviruses were detected in a majority of samples using BMFS (37/42) and two-phase separation (32/42). There was statistically more frequent detection of Sabin-like PV type 3 in samples concentrated with BMFS (22/42) than by two-phase separation (14/42, p = 0.035), possibly due to greater effective volume assayed (870 mL vs. 150 mL). Despite this effective volume assayed, there was no statistical difference in Sabin-like PV type 1 and Sabin-like PV type 2 detection between these methods (9/42 vs. 8/42, p = 0.80 and 27/42 vs. 32/42, p = 0.18, respectively). This study demonstrated that BMFS can be used for PV environmental surveillance and established a feasible study design for future research.The Paul G. Allen Family Foundation (Grant No. NPT.1938–603689), and was managed by the Bill and Melinda Gates Foundation. This work was supported in part by the UW NIEHS sponsored Biostatistics, Epidemiologic and Bioinformatic Training in Environmental Health (BEBTEH) Training Grant, Grant#: NIEHS T32ES015459.http://link.springer.com/journal/12560hj2020Medical Virolog