In October 2020 Digital Journal reported on a new rapid test method for the assessment of viral particles in wastewater, including the detection of the novel coronavirus responsible for the COVID-19 diseases (the virsu SARS-CoV-2). The test, and the underpinning assumption that the levels of virus particles detected in wastewater can provide a meaningful assessment of potential cases in a given location, appears to be borne out from a new study.
The new wastewater sampling work is titled: “Wastewater Analysis of SARS-CoV-2 as a Predictive Metric of Positivity Rate for a Major Metropolis“. This one a larger-scale study into a big city. The study discovered that wastewater spikes in SARS-CoV-2 present clinical positives by two weeks. This provides health agencies with a significant lead time and of thereby providing an advantage for getting a handle on outbreaks before they happen and to put appropriate health policies in place.
There is a growing body of work that suggests wastewater monitoring for SARS-CoV-2 can provide an important epidemiological indicator of community infection dynamics as well as for disease prevalence.
In the research, conducted in Houston, Texas, it is reported that wastewater viral RNA levels of SARS-CoV-2 in a major metropolis can be used as this type of indicator. The area selected served over 3.6 million people geographically and there were 39 distinct sampling sites from which samples could be drawn from.
The researchers assessed viral RNA levels each week for a period of 22 weeks. The time period was both before, during, and after a major surge in cases. To ensure the reliability of the data, tests were undertaken simultaneously at two independent laboratories.
It was found that SARS-CoV-2 RNA wastewater levels were a strong predictive indicator of trends in the nasal positivity rate two-weeks in advance. In addition, wastewater viral RNA loads were found to offer a robust tracking of positivity rate for populations served by individual treatment plants.
Such findings can be used in real-time to assist with public health interventions, such as the deployment of testing services and to increase the level of public information aimed at viral spread prevention. This approach may be especially useful to resource-poor communities with limited access to healthcare facilities.
