The Life Science Research (LSR) department of the German Diagnostics Industry Association (VDGH) supports the implementation of molecular biological wastewater analyses in national testing strategies as proposed by the EU Commission (1) and agrees with the findings of the German Bundestag's scientific service (2): Molecular biological analyses of wastewater samples using PCR and sequencing techniques are suitable as a permanent epidemiological early warning system.
In this way, case numbers of symptomatic and asymptomatic cases can be recorded holistically and at an early stage and virus variants can also be tracked. The member companies of the VDGH are ready with innovative technologies to support pandemic management.
Explanation:
1. early warning system
SARS-CoV-2 can be detected in municipal wastewater because infected people excrete the virus (3). Compared to the reporting figures from the public health service, wastewater-based data is available five to ten days earlier (4). The analysis results can be used to map the incidence of infection and the existing variants of the pathogen within the wastewater catchment area, and thus within the population. Individual privacy rights are preserved, but the protection of the population is increased.
2. long-term monitoring
Implementing molecular biological wastewater analysis today is an investment in the future, as SARS-CoV-2 is likely to develop into an endemic pathogen (5). In addition to monitoring the current course of the pandemic, molecular biological applications also allow the versatile detection of known mutated pathogens, other pathogens or intrinsic pathogen properties, such as antibiotic resistance of bacterial pathogens (6).
Molecular biological wastewater analyses can be established as a sustainable preventive measure and protect the health of the population from various pathogens. This reduces the burden on the healthcare system and saves costs.
Reasons:
3. inclusion of asymptomatic courses expands the number of cases
In the current testing strategy, asymptomatic courses of disease are recorded by means of citizen testing, among other things. According to a study by the University of Bonn, the rapid antigen tests used there were able to significantly contain the incidence of infection (7).
These individual tests are currently on the decline due to the relaxation of pandemic measures. In addition, the number of asymptomatic patients may increase due to the steadily rising vaccination rate. This growing gap in case detection can be closed by wastewater analyses: Wastewater-based epidemiology provides an indication of the number of unreported cases and for this reason is a useful component for holistic case detection, particularly for periods of low prevalence but also after herd immunity has been achieved.
4. ramp up individual testing in the event of increased incidence in wastewater samples
The analysis of wastewater samples can detect a renewed increase in incidence at an early stage and individual tests (such as PCR tests or rapid antigen tests) can be used regionally in a targeted manner in the population to quickly contain new sources of infection. This targeted use of individual tests saves resources.
Wastewater analyses are also suitable for areas with limited clinical or laboratory capacity.
5 Long-term cost savings despite comprehensive monitoring
According to a recent memo from the EU Commission, the implementation costs for molecular biological analysis of wastewater samples in a wastewater treatment plant amount to around €25,000 per year (8). These investments cover regular monitoring within a wastewater treatment plant. They are also an investment in the future, as molecular biological methods can be used in a variety of ways.
Implementation strategies:
6. flexible adaptation of the necessary assays - pathogen-specific modification quickly and easily possible
Reagents, assays and devices are required for molecular biological methods: devices are one-off investments with a long service life; assays are adapted precisely to the pathogen to be detected. The prompt modification of these assays also enables rapid adaptation to mutated pathogens or new pathogens or new circumstances (e.g. antibiotic resistance of bacterial pathogens) (9, 10, 11).
Nucleic acid amplification techniques such as RT-qPCR (real-time quantitative PCR) or dPCR (digital PCR) provide quantitative detection of SARS-CoV-2.
Nucleic acid sequencing techniques such as NGS (next generation sequencing) or deep sequencing can check the genetic material of the pathogen for mutations and thus detect variants (12).
7 From research to application
The BMBF has already recognized the potential of wastewater-based epidemiology and is supporting projects such as COVIDready and CoroMoni, which the VDGH welcomes.
Taking international research results together, it can already be concluded that the scientific expertise is outstanding and that widespread application should be the next step. The EU Commission Recommendation EU 2021/472 and numerous other studies identify standards that are already being used by individual wastewater treatment plants (1, 13).
8. integrate wastewater-based epidemiology as a management tool for measures
There is currently only a low incidence of infection in Germany. In the fall of 2021, however, new waves of infection may be triggered by the failure to achieve herd immunity (vaccination) and by pathogen variants.
The case numbers have so far been based on the data reported by the health authorities. Epidemiological data from wastewater analyses can be used to determine the number of cases very effectively, as they identify the incidence of infection several days earlier than the medically recorded data. For this reason, Germany now needs data analysis and modeling from medically recorded and wastewater-based case numbers, which should be combined in a surveillance monitor or "dashboard".
In the Netherlands, corresponding data is already being incorporated into decisions by the authorities (14). In Germany, there are successful regional pilot projects in individual municipalities. The aim should now be to implement a nationwide dashboard.
The VDGH member companies are ready with their expertise and innovative product portfolio to support reliable wastewater monitoring in Germany.
References:
(1) https://eur-lex.europa.eu/legal-content/DE/TXT/?uri=CELEX:32021H0472
(2) Cordula Seeger (2021). WD 8 - 3010-059/21
https://www.bundestag.de/resource/blob/848440/484417db3669d04d1980cadb380de056/Abwasse r-Covid-19-data.pdf
(3) Westhaus, Weber et al. (2020). Science of The Total Environment, Vol. 751, 2021.
https://doi.org/10.1016/j.scitotenv.2020.141750
(4) Agrawal et al. (2021)a. Sci Rep 11, 5372 (2021).
https://doi.org/10.1038/s41598-021-84914-2
(5) Lavine et al (2021). Science, Vol. 371, Issue 6530, pp. 741-745.
DOI: 10.1126/science.abe6522
(7) Gabler et al. (2021). ECONtribute Discussion Paper No. 100.
https://www.econtribute.de/RePEc/ajk/ajkdps/ECONtribute_100_2021.pdf
(9) Hellmer et al. (2014). Appl Environ Microbiol. 2014 Nov, 80 (21), pp 6771-6781.
DOI: 10.1128/AEM.01981-14
(10) Brouwer et al. (2018). PNAS, Vol. 115, No. 45.
DOI: 10.1073/pnas.1808798115
(11) Jahne et al. (2020). Water Research, Vol. 169.
https://doi.org/10.1016/j.watres.2019.115213
(12) Agrawal et al. (2021)b. Microbiol Resour Announc. 2021 Apr; Vol. 10, No. 15.
https://doi.org/10.1128/MRA.00280-21.
(14) https://coronadashboard.government.nl/landelijk/rioolwater