RESUMEN
Infectious disease surveillance is vitally important to maintaining health security, but these efforts are challenged by the pace at which new pathogens emerge. Wastewater surveillance can rapidly obtain population-level estimates of disease transmission, and we leverage freedom from disease principles to make use of non-detection of SARS-CoV-2 in wastewater to estimate the probability that a community is free from SARS-CoV-2 transmission. From wastewater surveillance of 24 treatment plants across upstate New York beginning in May 2020, we observed a reliable limit of detection of 0.3--0.5 cases per 10,000 population. No COVID-19 cases were reported 40% of the time following a non-detection of SARS-CoV-2 in wastewater, and cases were less than 1 daily case per 10,000 population 97% of the time following non-detection. Trends in the intensity of SARS-CoV-2 in wastewater correlate with trends in COVID-19 incidence and test positivity ({rho}>0.5), with the greatest correlation observed for active cases and a three-day lead time between wastewater sample date and clinical test date. Wastewater surveillance can cost-effectively demonstrate the geographic extent of the transmission of emerging pathogens, confirming that transmission is absent or under control and alerting of an increase in transmission. If a statewide wastewater surveillance platform had been in place prior to the onset of the COVID-19 pandemic, policymakers would have been able to complement the representative nature of wastewater samples to individual testing, likely resulting in more precise public health interventions and policies.
