Title : Wastewater surveillance for emerging viruses
Abstract:
Since it was declared a pandemic by the World Health Organization in March 2020, SARS-CoV-2 has been known to exhibit notoriety due to the number of people infected and dead over a period of three years. This study was to determine the presence of SARS-CoV-2 RNA viral fragments in wastewater samples from two wastewater treatment plants in Baltimore over a period of one year. The samples were concentrated by the Polyethylene Glycol 8000 (PEG) method, and RNA fragments were purified using the QiAmp Viral RNA Mini Kit. RT-PCR and qPCR assays were performed, and Cq values below 40 were analyzed and presented as gene copies/L. N1 and N2 genes were detected in both WWTP samples, with N1 having log10 gene copies ranging from 1.38 - 3.34 gc/l and N2 ranging from 1.88-3.20 gc/l. Covid19 hospitalization cases in Baltimore County and City were observed to be 40-42 % positively correlated with the copies of N-genes detected in the WWTP-A. On the contrary, the N-genes (N1 and N2) from both WWTPs exhibited a very weak positive and negative relationship with wastewater physical parameters such as pH, electrical conductivity, total dissolved solutes, salinity, and temperature. The reduction in positive correlation between N genes detected and hospitalization cases could be attributed to an increase in immunity amongst the population in both counties surveyed. There is a need to ascertain the effect of physical parameters changes from the sampling point to the processing point on the capture and detection of SARS-CoV-2 viral RNA in wastewater. We have utilized wastewater surveillance for other viruses such as Norovirus and Mpox.
