# Wastewater Surveillance for SARS-CoV-2 in Rural Kentucky, 2021–2023

## TL;DR

Wastewater testing for SARS-CoV-2 in rural Kentucky showed strong correlations with reported cases, offering a useful tool for tracking the pandemic in underserved areas.

## Contribution

The study implemented and evaluated wastewater surveillance in rural communities, revealing its effectiveness in tracking SARS-CoV-2.

## Key findings

- Significant correlations between wastewater SARS-CoV-2 concentrations and reported cases were found at seven of ten sites.
- The strongest correlations occurred during the Delta variant period.
- The model predicted higher case numbers than official reports in the latter part of the study.

## Abstract

Wastewater testing for SARS-CoV-2 provided useful public health information during the COVID-19 pandemic yet was underutilized in rural communities. We addressed this gap by implementing wastewater surveillance and assessing its performance in 10 communities in Eastern Kentucky. We collected wastewater samples 1–2 times weekly at 10 wastewater treatment plants (WWTPs) from May 2021 until April 2023 and measured SARS-CoV-2 RNA concentrations using polymerase chain reaction testing. We calculated time-lagged correlations between wastewater concentrations and county-level reported COVID-19 cases by site. We developed a generalized linear model to estimate COVID-19 incidence from wastewater SARS-CoV-2 concentrations. The 10 participating WWTPs served 2430 to 35,575 customers, and 90% were in rural counties. We cumulatively analyzed 818 wastewater samples. Correlations between wastewater SARS-CoV-2 concentrations and COVID-19 cases were significant at seven of the WWTPs and were strongest during the Delta variant period. The incidence density model predicted more COVID-19 cases during the latter study period (May 2022–April 2023) than were officially reported. Wastewater surveillance data in these rural communities corroborated clinical case data and may have more accurately described community disease levels later in the pandemic.