As the Covid-19 pandemic marches across America, causing record-breaking numbers of cases, almost every solution for controlling the disease includes more testing, especially as cities and states try to reopen. But with states hitting their limits on testing, we need new tools for understanding Covid-19 transmission. A national wastewater surveillance program offers a cost-effective approach to track Covid-19 across the majority of the U.S. population and provide early warnings of resurgence.
Simply testing individuals with symptoms won’t be enough to track how many people are infected. Given the high degree of asymptomatic spread — even in the absence of superspreading events — we need a national strategy that relies heavily on surveillance. Experts increasingly argue that we should be testing nursing home residents every week. Some universities are planning to test every student multiple times per week. And the federal government is talking about pooled testing as a strategy for testing large groups of individuals at once. The hope is that such testing, when coupled with robust contact tracing, can identify infections before they spread.