Original article
Vol. 154 No. 3 (2024)
Association between the number of symptomatic mpox cases and the detection of mpox virus DNA in wastewater in Switzerland: an observational surveillance study
- Claudia Bagutti
- Monica Alt Hug
- Philippe Heim
- Evelyn Ilg Hampe
- Philipp Hübner
- Timothy R. Julian
- Katrin N. Koch
- Kerstin Grosheintz
- Melanie Kraus
- Carla Schaubhut
- Rahel Tarnutzer
- Eva Würfel
- Simon Fuchs
- Sarah Tschudin-Sutter
Summary
AIM OF THE STUDY: The COVID-19 pandemic has drawn attention to the benefit of wastewater-based epidemiology, particularly when case numbers are underreported. Underreporting may be an issue with mpox, where biological reasons and stigma may prevent patients from getting tested. Therefore, we aimed to assess the validity of wastewater surveillance for monitoring mpox virus DNA in wastewater of a Central European city and its association with official case numbers.
METHODS: Wastewater samples were collected between 1 July and 28 August 2022 in the catchment area of Basel, Switzerland, and the number of mpox virus genome copies they contained was determined by real-time quantitative PCR. Logistic regression analyses were used to determine the odds of detectability of mpox virus DNA in wastewater, categorised as detectable or undetectable. Mann–Whitney U tests were used to determine associations between samples that tested positive for the mpox virus and officially reported cases and patients’ recorded symptomatic phases.
RESULTS: Mpox virus DNA was detected in 15 of 39 wastewater samples. The number of positive wastewater samples was associated with the number of symptomatic cases (odds ratio [OR] = 2.18, 95% confidence interval (CI) = 1.38–3.43, p = 0.001). The number of symptomatic cases differed significantly between days with positive versus negative wastewater results (median = 11 and 8, respectively, p = 0.0024).
CONCLUSION: Mpox virus DNA was detectable in wastewater, even when officially reported case numbers were low (0–3 newly reported mpox cases corresponding to 6–12 symptomatic patients). Detectability in wastewater was significantly associated with the number of symptomatic patients within the catchment area. These findings illustrate the value of wastewater-based surveillance systems when assessing the prevalence of emerging and circulating infectious diseases.
References
- European Centre for Disease Prevention and Control. Risk assessment: monkeypox multi-country outbreak. Stockholm: ECDC; 2022 23 May 2022. Available from: https://www.ecdc.europa.eu/en/publications-data/risk-assessment-monkeypox-multi-country-outbreak Last accessed 2023-07-29
- Isidro J, Borges V, Pinto M, Sobral D, Santos JD, Nunes A, et al. Phylogenomic characterization and signs of microevolution in the 2022 multi-country outbreak of monkeypox virus. Nat Med. 2022 Aug;28(8):1569–72. [cited 2023 Jul 29] 10.1038/s41591-022-01907-y
DOI: https://doi.org/10.1038/s41591-022-01907-y
- Isidro J, Borges V, Pinto M, Sobral D, Santos JD, Nunes A, et al. Addendum: phylogenomic characterization and signs of microevolution in the 2022 multi-country outbreak of monkeypox virus. Nat Med. 2022 Oct;28(10):2220–1. [cited 2023 Jul 29] 10.1038/s41591-022-02036-2
DOI: https://doi.org/10.1038/s41591-022-02036-2
- Taylor L. Monkeypox: WHO to rename disease to prevent stigma. BMJ. 2022 Jun;377:o1489. [cited 2023 Jul 29] 10.1136/bmj.o1489
DOI: https://doi.org/10.1136/bmj.o1489
- De Baetselier I, Van Dijck C, Kenyon C, Coppens J, Michiels J, de Block T, et al.; ITM Monkeypox study group. Retrospective detection of asymptomatic monkeypox virus infections among male sexual health clinic attendees in Belgium. Nat Med. 2022 Nov;28(11):2288–92. [cited 2023 Jul 29] 10.1038/s41591-022-02004-w
DOI: https://doi.org/10.1101/2022.07.04.22277226
- Miura F, van Ewijk CE, Backer JA, Xiridou M, Franz E, Op de Coul E, et al. Estimated incubation period for monkeypox cases confirmed in the Netherlands, May 2022. Euro Surveill. 2022 Jun;27(24):2200448. [cited 2023 Jul 29] 10.2807/1560-7917.ES.2022.27.24.2200448
DOI: https://doi.org/10.2807/1560-7917.ES.2022.27.24.2200448
- Girón-Guzmán I, Díaz-Reolid A, Truchado P, Carcereny A, García-Pedemonte D, Hernáez B, et al. Spanish wastewater reveals the current spread of Monkeypox virus. Water Res. 2023 Mar;231:119621. [cited 2023 Jul 29] 10.1016/j.watres.2023.119621
DOI: https://doi.org/10.1016/j.watres.2023.119621
- Wolfe MK, Yu AT, Duong D, Rane MS, Hughes B, Chan-Herur V, et al. Use of Wastewater for Mpox Outbreak Surveillance in California. N Engl J Med. 2023 Feb;388(6):570–2. [cited 2023 Jul 29] 10.1056/NEJMc2213882
DOI: https://doi.org/10.1056/NEJMc2213882
- de Jonge EF, Peterse CM, Koelewijn JM, van der Drift AR, van der Beek RF, Nagelkerke E, et al. The detection of monkeypox virus DNA in wastewater samples in the Netherlands. Sci Total Environ. 2022 Dec;852:158265. [cited 2023 Jul 29] 10.1016/j.scitotenv.2022.158265
DOI: https://doi.org/10.1016/j.scitotenv.2022.158265
- Wurtzer S, Levert M, Dhenain E, Boni M, Tournier JN, Londinsky N, et al. First detection of Monkeypox virus genome in sewersheds in France. Environ Sci Technol Lett. 2022;9(11):991–6. [cited 2023 Jul 29] 10.1021/acs.estlett.2c00693
DOI: https://doi.org/10.1021/acs.estlett.2c00693
- La Rosa G, Mancini P, Veneri C, Ferraro GB, Lucentini L, Iaconelli M, et al. Detection of Monkeypox virus DNA in the wastewater of an airport in Rome, Italy: expanding environmental surveillance to emerging threats. Emerg Infect Dis. 2023;29(1):193–6. [cited 2023 Jul 29] 10.3201/eid2901.221311
DOI: https://doi.org/10.3201/eid2901.221311
- Mejia EM, Hizon NA, Dueck CE, Lidder R, Daigle J, Wonitowy Q, et al. Exploration of wastewater surveillance for Monkeypox virus. medRxiv. 2022:2022.11.10.22282091. 10.1101/2022.11.10.22282091 Last accessed 2023-07-29 10.1101/2022.11.10.22282091
- Bagutti C, Alt Hug M, Heim P, Maurer Pekerman L, Ilg Hampe E, Hübner P, et al. Wastewater monitoring of SARS-CoV-2 shows high correlation with COVID-19 case numbers and allowed early detection of the first confirmed B.1.1.529 infection in Switzerland: results of an observational surveillance study. Swiss Med Wkly. 2022 Jun;152(152):w30202. [cited 2023 Jul 29] 10.4414/smw.2022.w30202 10.4414/SMW.2022.w30202
DOI: https://doi.org/10.4414/SMW.2022.w30202
- Federal Office of Public Health. Reporting systems for infectious diseases requiring notication. Federal Office of Public Health FOPH Bern, Switzerland [https://www.bag.admin.ch/bag/de/home/krankheiten/infektionskrankheiten-bekaempfen/meldesysteme-infektionskrankheiten/meldepflichtige-ik/meldeformulare.html. Last accessed 2023-07-29
- Suñer C, Ubals M, Tarín-Vicente EJ, Mendoza A, Alemany A, Hernández-Rodríguez Á, et al.; Movie Group. Viral dynamics in patients with monkeypox infection: a prospective cohort study in Spain. Lancet Infect Dis. 2023 Apr;23(4):445–53. [cited 2023 Jul 29] 10.1016/S1473-3099(22)00794-0
- Chen W, Bibby K. Model-based theoretical evaluation of the feasibility of using wastewater-based epidemiology to monitor monkeypox [Last accessed]. Environ Sci Technol Lett. 2022;9(9):772–8. 10.1021/acs.estlett.2c00496
DOI: https://doi.org/10.1021/acs.estlett.2c00496
- Wölfel R, Corman VM, Guggemos W, Seilmaier M, Zange S, Müller MA, et al. Virological assessment of hospitalized patients with COVID-2019. Nature. 2020 May;581(7809):465–9. [cited 2023 Jul 29] 10.1038/s41586-020-2196-x
DOI: https://doi.org/10.1038/s41586-020-2196-x