COVID Regional Wastewater Testing Program
Since July 2020, the City of Moscow Water Reuse and Reclamation Facility has partnered with the University of Idaho Biological Sciences and Civil & Environmental Engineering Departments, in partnership with the Institute for Modeling Collaboration and Interaction, to coordinate a regional wastewater testing program to monitor wastewater for the presence of SARS-CoV-2, the virus that causes COVID-19. Prior to the U of I partnership, the City worked with Biobot Analytics, Inc. beginning in May 2020.
Results shown in the graph here present the concentration of the COVID-19 viral fragments found in Moscow's wastewater from January 2020 to present. The Moscow Water Reclamation and Reuse Facility serves the area within Moscow City limits and the Southeast Moscow Sewer District located just outside of Moscow's east city limit boundary. These viral fragments are shed from infected individuals at or even before symptoms' onset. Viral fragments are also shed from individuals who never show symptoms. Because it detects both symptomatic and asymptomatic infections, wastewater-based detection provides an agnostic assessment of SARS-CoV-2 circulation in a community. However, wastewater testing does not provide a method to determine the number of infected people, as people shed the virus at different rates and the wastewater concentration is affected by changes in flows and dilution such as a significant rain event. What we can determine from the chart, however, is the changing rate of infection in our community. A comparison of infection rates – based on clinical test results – to the wastewater test results shows the concentration of viral fragments in wastewater increase at the same time or in advance of the community experiencing an increase of infection rates. In short, the wastewater studies provide complementary surveillance to monitor the spread of the virus in our community; results can help community leaders and health care providers in making more proactive decisions to protect the community.
The City of Moscow began variant testing with GT Molecular in April of 2021, submitting samples about every 2 weeks. The below table shows the copies per liter, the predominant variant found at the time of testing, and the 7 day average of confirmed positives as reported to USA facts. The attached graph indicates the changes in confirmed cases in Latah county as reported by USA facts and the copies per L of COVID over time as determined through GT Molecular.
NORMALIZED VIRAL COPIES/L
7-DAY COUNTY CONFIRMED MOVING AVG.
PREDOMINANT VARIANT STRAIN
|3/20/22||36,661||0||Omicron (BA.1 + BA.2 present)|
|4/3/2022||115,824||0||Omicron (BA.1 + BA.2 present)|
|4/17/2022||104,826||1||Omicron (BA.1 + BA.2 present)|
|5/2/2022||156,962||4||Omicron (BA.1 + BA.2 present)|
|5/15/2022||446,390||5||Omicron (BA.1/BA.2 present)|
|5/31/2022||693,881||5||Omicron (BA.2 present)|
|6/15/2022||399,779||5||Omicron (BA.2 present)|
|6/26/2022||1,039,795||5||Omicron (BA.2.12.1, BA.4, BA.5 present)|
|7/11/2022||444,475||7||Omicron (BA2.12.1, BA.4. BA.5 present)|
|7/25/2022||476,952||8||Omicron (BA2.12.1, BA.4. BA.5 present)|
|8/8/2022||445,280||3||Omicron (BA2.12.1, BA.4, BA.5 present)|
|8/22/2022||2,350,666||3||Omicron (BA.4, BA.5 present)|
|9/6/2022||1,044,271||5||Omicron (BA 1, BA.4, BA.5 present)|
|9/18/2022||475,891||3||Omicron (BA.4, BA.5 present)|
BDL =Below detectable levels