When clinical studies emerged showing that people who test positive for SARS-CoV-2 shed the virus in their stool, the sewer seemed like an obvious place to look for it. Wastewater surveillance can be used at the community level to see potential outbreak clusters before clinical diagnosis, especially in areas where COVID-19 prevalence rates far exceed testing rates.

The problem is that the virus is heavily diluted in the waste stream because of how many people's bathrooms drain into it, not to mention all the other junk they flush. Surveillance depends on concentrating the viral particles from the wastewater to detect these low levels. This viral concentration step is typically the major bottleneck in wastewater analyses because it's laborious and time-consuming. Our robot system takes a different, quicker approach.

Cities, schools and businesses around the country are using wastewater surveillance to find coronavirus in their midst.

Wastewater surveillance is especially useful as an early-alert system for high-risk areas, such as communities where undocumented residents may be cautious about individual testing.

The most commonly used viral concentration technique uses filters and can take anywhere from six to eight hours to transform a couple dozen sewage specimens into samples that can then be tested for the presence of SARS-CoV-2. Our new protocol concentrates 24 samples in a single 40-minute run.