Scientific researchers and health officials say they can follow an outbreak of the novel coronavirus in a community by examining its wastewater. Such studies could provide a valuable addition to the tools of public health agencies, they say. The idea is simple. Studies show that genetic material from the coronavirus can be found in the waste products of about half of patients with COVID-19, the disease caused by the virus. Researchers can find that genetic material by doing wastewater analysis. Over time, such tests can show changes in infection rates in a community.