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COVID-19

Wastewater Sampling Reveals New Insights into COVID-19 Dynamics

Strategic Insights

— 2 min read

Researchers from Louisiana State University have conducted a comprehensive study on the effectiveness of wastewater sampling in monitoring COVID-19 prevalence. The study collected samples from two wastewater treatment plants and three neighborhoods in Shreveport, LA, and revealed significant correlations between SARS-CoV-2 levels in wastewater and the number of individual positive cases at the county level. The findings suggest that the characteristics of wastewater sampling sites, including viral prevalence and population coverage, are major determinants of the public health information that can be derived from monitoring those sites.

Key Takeaways:

  • The study collected grab samples twice per month from two wastewater treatment plants and three neighborhoods in Shreveport, LA, and normalized the data using pepper mild mottle virus (PMMoV) to correct for the size of the contributing population.
  • Both treatment plants showed a significant correlation between SARS-CoV-2 levels in wastewater and the number of individual positive SARS-CoV-2 cases at the county level.
  • The smaller plant, WWTP B, had a significantly larger viral prevalence per capita, while the larger plant, WWTP A, was predictive of county positive SARS-CoV-2 cases up to 12 days in advance.
  • The neighborhood sampling site with the higher level of SARS-CoV-2 per capita showed the strongest relationship to both county cases and the earliest prediction of their increase.
  • The study highlights the importance of considering viral prevalence and population coverage when interpreting wastewater sampling data for public health purposes.

Statistics:

  • The study collected samples from approximately 200,000 residents in Shreveport, LA.
  • The neighborhoods and wastewater treatment plants varied in viral prevalence and population coverage, with WWTP B having a significantly larger viral prevalence per capita.
  • The correlation between SARS-CoV-2 levels in wastewater and county-level positive cases was significant for both WWTP plants.
  • WWTP A was predictive of county positive SARS-CoV-2 cases up to 12 days in advance, while WWTP B was only predictive out to 7 days.
  • The neighborhood with the higher level of SARS-CoV-2 per capita was predictive of county cases and showed the earliest increase in positive cases.

Sources:

  • A comparison of viral prevalence versus population coverage as drivers of public health information derived from wastewater sampling. Heliyon, 2025,11(11):e43423. (Heliyon - http://www.heliyon.com). The publisher for Heliyon is Elsevier.
  • NewsRx. Research from Louisiana State University Reveals New Findings on COVID-19 (A comparison of viral prevalence versus population coverage as drivers of public health information derived from wastewater sampling). Medical Letter on the CDC & FDA. June 22, 2025; p 158.

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