Waste water analysis closely fitted trend of persons testing COVID positive--study

Predicting COVID-19 Incidence Using Wastewater Surveillance Data, Denmark, October 2021–June 2022 Predicting COVID-19 Using Wastewater Surveillance Emerging Infectious Diseases journal

Analysis of wastewater is used in many settings for surveillance of SARS-CoV-2, but it remains unclear how well wastewater testing results reflect incidence. Denmark has had an extensive wastewater analysis system that conducts 3 weekly tests in ≈200 sites and has 85% population coverage; the country also offers free SARS-CoV-2 PCR tests to all residents. Using time series analysis for modeling, we found that wastewater data, combined with information on circulating variants and the number of human tests performed, closely fitted the incidence curve of persons testing positive