Cost of wastewater-based environmental surveillance for SARS-CoV-2: evidence from pilot sites in Blantyre, Malawi and Kathmandu, Nepal

Ngwira, L. G. et al. (2022) Cost of wastewater-based environmental surveillance for SARS-CoV-2: evidence from pilot sites in Blantyre, Malawi and Kathmandu, Nepal. PLoS Global Public Health, 2(12), e0001377. (doi: 10.1371/journal.pgph.0001377) (PMID:36962924) (PMCID:PMC10021894)

Abstract

Environmental surveillance of rivers and wastewater for SARS-CoV-2 detection has been explored as an innovative way to surveil the pandemic. This study estimated the economic costs of conducting wastewater-based environmental surveillance for SARS-CoV-2 to inform decision making if countries consider continuing these efforts. We estimated the cost of two SARS-CoV-2 environmental surveillance pilot studies conducted in Blantyre, Malawi, and Kathmandu, Nepal. The cost estimation accounted for the consumables, equipment, and human resource time costs used for environmental surveillance from sample selection until pathogen detection and overhead costs for the projects. Costs are reported in 2021 US$ and reported as costs per month, per sample and person per year. The estimated costs for environmental surveillance range from $6,175 to $8,272 per month (Blantyre site) and $16,756 to $30,050 (Kathmandu site). The number of samples processed per month ranged from 84 to 336 at the Blantyre site and 96 to 250 at the Kathmandu site. Consumables costs are variable costs influenced by the number of samples processed and are a large share of the monthly costs for ES (ranging from 39% to 72%). The relatively higher costs per month for the Kathmandu site were attributable to the higher allocation of dedicated human resources and equipment to environmental surveillance for SARS-CoV-2 compared to the Blantyre site where these resources were shared with other activities. The average cost per sample ranged from $25 to $74 (Blantyre) and $120 to $175 (Kathmandu). There were associated economies of scale for human resources and equipment costs with increased sample processing and sharing of resources with other activities. The cost per person in the catchment area per year ranged from $0.07 to $0.10 in Blantyre and $0.07 to $0.13 in Kathmandu. Environmental surveillance may be a low-cost early warning signal for SARS-CoV-2 that can complement other SARS-CoV2 monitoring efforts.

• Item Type: Articles
• Additional Information: This work was funded in part by the Bill & Melinda Gates Foundation grant number 583722 (to PATH) and by the Global Innovation Fund grant number 583820 (to PATH). Research reported in this publication was also supported by core funding from Wellcome to MLW (Wellcome Asia and Africa Programme grant 206545/Z/17/Z), BMGF Investment OPP1155752 (to NF) and an NIH Fogarty Fellowship K01TW010853 (to KGB).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Barnes, Dr Kayla
• Authors: Ngwira, L. G., Sharma, B., Shrestha, K. B., Dahal, S., Tuladhar, R., Manthalu, G., Chilima, B., Ganizani, A., Rigby, J., Kanjerwa, O., Barnes, K., Anscombe, C., Mfutso-Bengo, J., Feasey, N., and Mvundura, M.
• College/School: College of Medical Veterinary and Life Sciences > School of Infection & Immunity
• Journal Name: PLoS Global Public Health
• Publisher: Public Library of Science
• ISSN: 2767-3375
• ISSN (Online): 2767-3375
• Copyright Holders: Copyright © 2022 Ngwira et al..
• First Published: First published in PLoS Global Public Health 2(12): e0001377
• Publisher Policy: Reproduced under a Creative Commons License