SARS CoV-2 Wastewater Testing - State of the Science
Prepared by J. Parr
The NELAC Institute, 210 S Lamar St, Weatherford, Texas, 76086-4114, United States
Contact Information: [email protected]; 817-308-0449
Wastewater-based epidemiology (WBE) has become widely recognized as a useful complement to clinical testing for monitoring and informing response to the spread of COVID-19. Key advantages of WBE include (1) it is a less resource-intensive way to gather information on large numbers of individuals, (2) it provides data on entire populations rather than just the subset of individuals who come in for clinical testing, and (3) it can serve as an early-warning system, given that fecal shedding of SARS-CoV-2 typically precedes symptom onset. The quantitative Polymerase Chain Reaction (PCR) assay can be used to supplement clinical testing. Accreditation has been used in a wide variety of industries to help laboratories in standardizing methodology, ensuring valid results that can be compared, and in ensuring competency amongst participating laboratories. TNI has a national laboratory accreditation program that could be adapted to accredit laboratories that test for SARS-CoV-2. While there is no specific standard for this testing, the laboratories themselves can be assessed under the TNI standard or the ISO/IEC 17025 standard. ACIL has been leading an effort to develop a checklist that could be used by laboratory assessors.
As discussed in more detail in a 2020 report, there is no doubt that accreditation to the TNI standard makes a difference in the quality of the data and in laboratory performance. ( https://nelac-institute.org/news.php?id=4370) Laboratories accredited to the TNI standard have documented significant improvements which include efficiency, demonstrated capability, and quicker reports. Traceability, training, quality assurance, and documentation all contribute to better decisions and confidence in the data for the accredited laboratories, data users and regulators. Specifically, some of the factors that create value through laboratory accreditation to the TNI Standard include:
* The reported result is a good measure of the true concentration.
* The reported result is of known and documented quality.
* The laboratory complied with mandated method requirements.
* The laboratory has a strong Quality Management System that helps ensure confidence in the result.
* The laboratory met customer requirements.
TNI is currently pursuing a plan to support this effort which includes the following actions:
* Creating an analyte code for SARS-CoV-2 and a technology code for the Polymerase Chain Reaction (PCR) assay used to perform the testing.
* Developing guidance materials on this topic that can help stakeholders understand how the TNI laboratory accreditation standard can be applied.
* Explore the demand and specific requirements for training of laboratory assessors or others using the PCR technology and follow up with development of appropriate training as needed.
* Exploring the feasibility of proficiency testing, interlaboratory comparison studies, or other comparable actions to objectively verify the competency of those laboratories that test for SARS-CoV-2.