Volume 30, Number 9—September 2024
Dispatch
Participatory, Virologic, and Wastewater Surveillance Data to Assess Underestimation of COVID-19 Incidence, Germany, 2020–2024
Anna Loenenbach1, Ann-Sophie Lehfeld1, Peter Puetz1, Barbara Biere1, Susan Abunijela, Silke Buda, Michaela Diercke, Ralf Dürrwald, Timo Greiner, Walter Haas, Maria Helmrich, Kerstin Prahm, Jakob Schumacher, Marianne Wedde, and Udo Buchholz
Table
List of surveillance systems and indicators used for participatory, virologic, and wastewater surveillance data to assess underestimation of COVID-19 incidence, Germany, 2020–2024*
| Abbreviations |
Definition |
Description and formulas |
|---|---|---|
| Surveillance systems | ||
| GNS | German notification system | Mandatory notification system for infectious diseases according to German Infection Protection Act |
| GW | GrippeWeb | Participatory ILI and non-ILI online surveillance system for the general population, which began in 2011 |
| VSS | Virological surveillance system | Established in primary care practices |
| WWS |
Wastewater surveillance system |
Monitors aggregated SARS-CoV-2 viral load in wastewater and began during calendar week 22 2022 |
| Indicator | ||
| GNS-I | German notification system incidence† | COVID-19 incidence reference indicator using data from GNS |
| GW-VPR-I | GrippeWeb and virologic positivity rate incidence† | COVID-19 incidence comparison indicator using data from GrippeWeb and VSS |
| Formula: Weekly GW-VPR-I = GW ILI incidence × VSS SARS-CoV-2 positivity rate among ILI patients + GW non-ILI incidence × VSS SARS-CoV-2 positivity rate among non-ILI patients | ||
| GW-SR-I | GrippeWeb self-reported testing results† | COVID-19 incidence comparison indicator using GrippeWeb self-reported pathogen detection results for self-tested or laboratory-confirmed positive tests; data collection started in calendar week 27, 2022 |
| Formula: COVID-19 incidence measured by GW-SR-I = weekly number of adult GW participants with any acute respiratory infection and a positive COVID-19 test ÷ weekly number of all reports of adults (ill or not ill) | ||
| SC2-VL-WW | Aggregated SARS-CoV-2 viral load in wastewater | COVID-19 comparison indicator using WWS system and expressed as the number of SARS-CoV-2 gene fragments per liter in wastewater |
| UEF | Underestimation factor | Two underestimation factors were calculated as an indicator to estimate the sensitivity of GNS-derived COVID-19 incidence with the help of GW and VSS surveillance data |
| Formulas: UEFGW-VPR-I = COVID-19 incidence measured by GW-VPR-I ÷ COVID-19 incidence measured by GNS-I UEFGW-SR-I = COVID-19 incidence measured by GW-SR-I ÷ COVID-19 incidence measured by GNS-I |
||
*ILI, influenza-like illness. †COVID-19 incidence indicator.
1These first authors contributed equally to this article.
Page created: July 23, 2024
Page updated: August 21, 2024
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