A-Z Index × Submit A-Z Index × Submit A-Z Index Search Dropdown × Submit Facebook Twitter LinkedIn Syndicate Emerging Infectious Disease journal ISSN: 1080-6059 Disclaimer: Early release articles are not considered as final versions. Any changes will be reflected in the online version in the month the article is officially released.
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Underlying the core goals of the Centers for Disease Control and Prevention National Wastewater Surveillance System (NWSS) in the United States is the need for robust and reliable pathogen data. The rapid build-out of the NWSS network and participation of many laboratories with varying expertise in environmental molecular methods has resulted in a lack of method standardization and poor data comparability. Proficiency testing is a powerful strategy to address this challenge. We describe preliminary outcomes from 2 proficiency testing rounds with 38 total participating laboratories, where reported respiratory virus concentrations from replicate samples spanned roughly 2 orders of magnitude; the program identified key opportunities for improvement. Although still in its infancy, this program proved an effective tool for quantifying variability across the network, offering preliminary insights on method performance, and improving data quality through laboratory support. Our results suggest that wastewater proficiency testing for disease surveillance will improve data quality and strengthen the NWSS.
Wastewater-based surveillance (WBS) for pathogens is increasingly recognized as a valuable complement to traditional clinical monitoring, serving as a leading indicator of increased disease transmission and providing less biased, cost-efficient community monitoring ( 1 , 2 ). Through the Centers for Disease Control and Prevention (CDC) National Wastewater Surveillance System (NWSS), the United States has established a network of laboratories reporting pathogen concentrations in wastewater, supporting public health decision-making ( 3 , 4 ). However, the rapid expansion of the network has outpaced the development of standardized protocols, resulting in substantial methodologic heterogeneity across laboratories ( 3 , 5 ).
With limited tools to assess the existing diverse methods used by laboratories with varied WBS experience, the comparability and utility of the data submitted to the NWSS program are compromised. Many potential sources of data variability in WBS are known, but only a handful of studies have systematically investigated their relative influence on pathogen recoveries ( 2 , 6 – 9 ). To date, very few interlaboratory comparisons have been conducted ( 10 , 11 ). Furthermore, many laboratories have insufficient resources for method optimization and operate with limited expertise and support.
A recent report from the National Academies of Sciences, Engineering, and Medicine emphasized the importance of cross-network data standardization for endurance of the network and pointed to proficiency testing (PT) as an avenue to improve data comparability ( 12 ). PT programs are a well-established mechanism in clinical and environmental testing for benchmarking performance ( 13 – 16 ), yet to our knowledge no such program exists for pathogens in wastewater, except for the Canada-focused program operated by the Ontario Clean Water Agency ( 17 ). Moreover, PT programs can provide insights on inter- and intra-laboratory variability, identify low- and high-performing…