Molecular virologist Arvind Varsani and evolutionary virologist Simona Kraberger are expat New Zealanders working at Arizona State University. During the coronavirus pandemic they've been using genetic tracing techniques to test wastewater to show community spread of the SARS-CoV-2 virus. Using wastewater samples collected across 10 US states, they have detected variants of the disease that have been missed through conventional clinical testing. They think this is due to high rates of asymptomatic spread (infected individuals showing little to no symptoms who still spread the virus). Their work is also revealing valuable information about when, where and how the disease spreads between different locations. Here in New Zealand The Institute of Environmental Science and Research (ESR) is currently conducting a two month trial sampling wastewater from places with and without managed isolation facilities nearby.