Updated Wastewater Testing Results

Bad news! After an undetectable level of virus in last week’s sample (October 4th–5th), this week’s wastewater sample (October 11th–12th) had detectable virus, although the level was not quite as high as it had been during August and September. 
The Yarmouth School Department reported that at least 7 individuals tested positive for SARS-CoV-2 this week (October 11th-15th): 4 at Yarmouth Elementary School and 3 at Harrison Middle School. The cases this week are the first cases reported at any Yarmouth school since September 21st. The presence of virus in Yarmouth’s wastewater this week may reflect viral contributions by one or more of the individuals from Yarmouth schools who tested positive this week.
The number of cases (9) reported by the Maine CDC for the 7-day period from October 4th to 10th was an increase from the 6 cases reported for each of the previous three weeks. This case count is higher than would be expected based on the undetectable level of virus for the October 4th–5th sample. With the shortage of available rapid tests, a testing backlog in the state laboratory, and a delay in counting cases due to the recent surge in cases in Maine, it is difficult to assess the accuracy of recent case counts from the state and their relationship to wastewater levels of SARS-CoV-2 virus. It is possible that the cases reported to Maine CDC for October 4th to 10th represent cases that occured prior to this time period, but which were not tallied and reported in a timely way. It is helpful to have the additional tests reported from the Yarmouth School Department’s pooled testing program and the weekly pop-up tests in Yarmouth to get a better sense of what is going on.
Vaccination of all eligible individuals and adherence to recommended practices for limiting virus transmission are key to reducing viral infections and ongoing transmission. Participation of students, teachers, and staff in pooled testing for SARS-CoV-2 at the Yarmouth schools and testing of individuals in non-school settings, as needed, also play an important role in identifying infected individuals so that appropriate isolation and quarantine can limit viral spread.

The Team would like to thank the Town of Yarmouth, the Yarmouth Community Coronavirus Task Force, and individual donations for funding Yarmouth’s wastewater testing program from late-August 2021 through late-February 2022.

Thanks also to Tom Connolly and Yarmouth Wastewater Treatment Facility staff for collecting the weekly samples; to Tom Downing, Gro Flatebo, Laura Coroi, and Gib Parrish for transporting wastewater samples from the Treatment Facility to the laboratory at Saint Joseph’s College; and to Yolanda Brooks at Saint Joseph’s College for analyzing the samples for SAR-CoV-2.