A comparison of viral prevalence versus population coverage as drivers of public health information derived from wastewater sampling

Résumé fourni par la source

Wastewater has previously been used to monitor infectious diseases, drugs of misuse, and chemical exposures, including relating the prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to the population served. Most wastewater studies have used wastewater treatment plant (WWTP) sampling to assess county-level dynamics in SARS-CoV-2 prevalence. However, little is known regarding how viral prevalence and population coverage at WWTP sites influence predictions of county-level dynamics in SARS-CoV-2. Even less information is available from sampling at the level of individual neighborhoods. In this study, samples were collected during the Delta wave of the SARS-CoV-2 pandemic at two WWTPs and three neighborhoods in Shreveport, LA (total population of approximately 200,000 residents). The neighborhoods (10k-20k residents) and WWTPs (15 % versus 80 %) varied in the prevalence of the virus as well as the percent of the overall population that they covered. Grab samples were collected twice per month 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. The plant serving a larger population, WWTP A, was predictive of county positive SARS-CoV-2 cases up to 12 days in advance, whereas the smaller population covering plant, WWTP B, was only predictive out to 7 days. At the level of the neighborhood, the 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. These findings suggest that the characteristics of wastewater sampling sites are major determinants of the public health information that can be derived from monitoring those sites.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.