One of the outcomes for the recent pandemic has been an advancement in medical science, most notably with mRNA vaccines. There are other areas as well where progress with scientific understanding has been made.
This includes an expansion of wastewater-based infectious disease surveillance systems, designed to monitor and anticipate disease trends in communities. A limitation with this approach is where there is an unsewered population (this is still a factor for some parts of the U.S.)
To build on the progress made during the height of COVID-19, the U.S. Centers for Disease Control and Prevention (CDC) launched the National Wastewater Surveillance System. Beginning in September 2020, this initiative was intended to help coordinate and build upon wastewater surveillance efforts.
During the pandemic, analyses provided continued information on where the virus was circulating and the degree of exposure risk (as reported by Digital Journal “Coronavirus detection in wastewater aids case count assessment”).
Developed processes involve analysing markers in a wastewater treatment plant to assess a target disease. In terms of the coronavirus responsible for the pandemic – SARS-CoV-2 three different PCR assays were used to tack for viral RNA. PCR is a reference to polymerase chain reaction, the method that is deployed to rapidly make millions to billions of copies of a specific genetic sample. This technique enables scientists to take a very small sample of material (in this case RNA extracted from a wastewater sample, which in turn has been shed by infected persons) and to amplify it to a large enough quantity to study it in detail.
A new report (“Wastewater-based Disease Surveillance for Public Health Action”), issued in January 2023, reviews the usefulness of community-level wastewater surveillance during the pandemic and assesses its potential value for control and prevention of infectious diseases beyond COVID-19.
As well as continuous monitoring, assessing archived samples is also of importance for tracking spread. Furthermore, conducting phylogenetic analysis of viral sequences from current and archival samples aids scientists aiming to assess the extent that a given virus, or another pathogen, is mutating.
The report concludes that wastewater surveillance is and will continue to be a valuable component of infectious disease management. To help local administrations create a scientific legacy, the report presents a vision for a national wastewater surveillance system that would track multiple pathogens simultaneously including having the resources to detect emerging pathogens.
The report also recommends approaches to address ethical and privacy concerns and develop a more representative wastewater surveillance system.
However, for the vision to become a reality in the U.S., sustained federal funding is required together with the willingness for different agencies to coordinate and collaborate.
