On Nov. 18, 2020, Oregon Health & Science University (OHSU) announced an initiative that will attempt to discern early signals of the novel coronavirus – and potentially prevent an outbreak – in four Portland neighborhoods through wastewater screening combined with voluntary saliva testing of area residents.

The test involved collecting samples from residents spitting into a specialized tube. The saliva test is an alternative to the standard nasopharyngeal test, which involves inserting a small swab deep within the nose to collect a sample of mucus.

Two metropolitan area wastewater utilities are assisting in the project: Wastewater samples were taken at four manhole locations by the city of Portland Bureau of Environmental Services and analyzed by the Washington County utility Clean Water Services.

The study aimed to correlate the prevalence of virus in wastewater to the number of positive tests among individuals. With that information, it may be possible to calibrate the rate of testing that would be required to head off an outbreak in other densely populated areas.