TY - JOUR

T1 - Implications of long-term sample storage on the recovery of viruses from wastewater and biobanking

AU - Farkas, Kata

AU - Fletcher, Jessica

AU - Oxley, James

AU - Ridding, Nicola

AU - Williams, Rachel C

AU - Woodhall, Nick

AU - Weightman, Andrew J

AU - Cross, Gareth

AU - Jones, Davey L

N1 - Copyright © 2024. Published by Elsevier Ltd.

PY - 2024/11/1

Y1 - 2024/11/1

N2 - Wastewater-based monitoring has been widely implemented worldwide for the tracking of SARS-CoV-2 outbreaks and other viral diseases. In many surveillance programmes, unprocessed and processed wastewater samples are often frozen and stored for long periods of time in case the identification and tracing of an emerging health threat becomes necessary. However, extensive sample bioarchives may be difficult to maintain due to limitations in ultra-freezer capacity and associated cost. Furthermore, the stability of viruses in such samples has not been systematically investigated and hence the usefulness of bioarchives is unknown. In this study, we assessed the stability of SARS-CoV-2, influenza viruses, noroviruses and the faecal indicator virus, crAssphage, in raw wastewater and purified nucleic aacid extracts stored at -80 °C for 6-24 months. We found that the isolated viral RNA and DNA showed little signs of degradation in storage over 8-24 months, whereas extensive decay viral and loss of qPCR signal was observed during the storage of raw unprocessed wastewater. The most stable viruses were noroviruses and crAssphage, followed by SARS-CoV-2 and influenza A virus. Based on our findings, we conclude that bioarchives comprised of nucleic acid extracts derived from concentrated wastewater samples may be archived long-term, for at least two years, whereas raw wastewater samples may be discarded after one year.

AB - Wastewater-based monitoring has been widely implemented worldwide for the tracking of SARS-CoV-2 outbreaks and other viral diseases. In many surveillance programmes, unprocessed and processed wastewater samples are often frozen and stored for long periods of time in case the identification and tracing of an emerging health threat becomes necessary. However, extensive sample bioarchives may be difficult to maintain due to limitations in ultra-freezer capacity and associated cost. Furthermore, the stability of viruses in such samples has not been systematically investigated and hence the usefulness of bioarchives is unknown. In this study, we assessed the stability of SARS-CoV-2, influenza viruses, noroviruses and the faecal indicator virus, crAssphage, in raw wastewater and purified nucleic aacid extracts stored at -80 °C for 6-24 months. We found that the isolated viral RNA and DNA showed little signs of degradation in storage over 8-24 months, whereas extensive decay viral and loss of qPCR signal was observed during the storage of raw unprocessed wastewater. The most stable viruses were noroviruses and crAssphage, followed by SARS-CoV-2 and influenza A virus. Based on our findings, we conclude that bioarchives comprised of nucleic acid extracts derived from concentrated wastewater samples may be archived long-term, for at least two years, whereas raw wastewater samples may be discarded after one year.

KW - Wastewater/virology

KW - SARS-CoV-2

KW - Biological Specimen Banks

KW - Norovirus/isolation & purification

KW - RNA, Viral

KW - Humans

KW - Viruses/isolation & purification

KW - COVID-19/virology

KW - Specimen Handling/methods

U2 - 10.1016/j.watres.2024.122209

DO - 10.1016/j.watres.2024.122209

M3 - Article

C2 - 39126986

VL - 265

SP - 122209

JO - Water research

JF - Water research

SN - 0043-1354

ER -