{Reference Type}: Journal Article
{Title}: Omicron COVID-19 Case Estimates Based on Previous SARS-CoV-2 Wastewater Load, Regional Municipality of Peel, Ontario, Canada.
{Author}: Cheng L;Dhiyebi HA;Varia M;Atanas K;Srikanthan N;Hayat S;Ikert H;Fuzzen M;Sing-Judge C;Badlani Y;Zeeb E;Bragg LM;Delatolla R;Giesy JP;Gilliland E;Servos MR;
{Journal}: Emerg Infect Dis
{Volume}: 29
{Issue}: 8
{Year}: 2023 08 28
{Factor}: 16.126
{DOI}: 10.3201/eid2908.221580
{Abstract}: We determined correlations between SARS-CoV-2 load in untreated water and COVID-19 cases and patient hospitalizations before the Omicron variant (September 2020-November 2021) at 2 wastewater treatment plants in the Regional Municipality of Peel, Ontario, Canada. Using pre-Omicron correlations, we estimated incident COVID-19 cases during Omicron outbreaks (November 2021-June 2022). The strongest correlation between wastewater SARS-CoV-2 load and COVID-19 cases occurred 1 day after sampling (r = 0.911). The strongest correlation between wastewater load and COVID-19 patient hospitalizations occurred 4 days after sampling (r = 0.819). At the peak of the Omicron BA.2 outbreak in April 2022, reported COVID-19 cases were underestimated 19-fold because of changes in clinical testing. Wastewater data provided information for local decision-making and are a useful component of COVID-19 surveillance systems.