SURVEILLANCE OF HOUSTON’S WASTEWATER TO TRACK COMMUNITY COVID-19 INFECTION DYNAMICS (Invited Presentation)

COVID-19 goes undetected in a large percentage of the population because many people are asymptomatic or experience only mild symptoms. Undiagnosed, infected individuals are contagious and play a role in the rapid transmission of the virus. Confirmed clinical cases of COVID-19 are a significant underestimate of the total number of COVID-19 cases, particularly in areas with limited testing capabilities. Fecal viral shedding presents the opportunity to use wastewater-based epidemiology (WBE) to monitor and track the spread of COVID-19 infection by testing for the virus in wastewater. Infections can be monitored using wastewater samples because they reflect a pooled urine and fecal sample of an entire community. Wastewater monitoring is an additional tool to monitor COVID-19 infection dynamics at a community scale to inform the allocation of healthcare resources and social distancing policies.

Houston Water treats an average of 250 million gallons of wastewater per day, and services over 2.1 million people at 39 wastewater treatment plants. In collaboration with Houston Health Department, Houston Water, and Baylor College of Medicine, we have been collecting, processing, and analyzing weekly untreated wastewater samples from all 39 wastewater treatment plants in Houston. SARS-CoV-2 has been detected in wastewater samples from every wastewater treatment plant. The data is being used to track trends (increases and decreases in viral load at each treatment plant), identify geographic areas that are experiencing high infection burdens, and identify areas that may be experiencing an outbreak (sharp increases in viral loads week over week). This talk will summarize the methods being using to measure SARS-CoV-2 in wastewater samples, how the data is being used by the Health Department, and how the wastewater virus data compares to available clinical test data.