Novel Wastewater Toolkit Flags Covid-19 Surges Using Multiple Data Sources

By standardizing, visualizing, and synthesizing a range of Covid-19 indicators–including case counts, hospitalizations, deaths, health care utilization, and wastewater data–the estimator offers insights into how the Covid-19 risk picture varies across different tracking methods, and the added value of each dataset to provide a more complete understanding of the risk level in a community.

The risk estimator has a few distinct features. First, it provides a composite risk score at the county level constructed by weighting and summing the different indicators mentioned above. The composite score ranges from 0 to 100, with 100 representing very high risk. Second, the risk estimator displays trends over time in wastewater viral concentrations alongside trends in other measures. This context helps public health officials understand how the risk picture is changing, what the future risk might look like, and if trends are similar across different data sources. Building off this, the estimator classifies risk directionality to highlight if risk is increasing, decreasing, or stable based on recent trends in the data. Lastly, the risk estimator has an alert function that indicates when risk is becoming significantly elevated compared to historical trends, which could signal the need for additional public health interventions. Showing how trends and alerts vary across different tracking methods, and when they align, gives officials more confidence to act or to take a watch and wait approach.

These features have been developed for public health officials without deep technical expertise, making wastewater data an accessible source for local health departments that have variable capacity. The interactive dashboard has intuitive data visualization, a user-friendly interface and updates in real-time — designed for every day, ongoing use.

Future Applications

 The Covid-SURGE toolkit, which includes the algorithm and risk estimator, represents a significant step forward in public health surveillance. Through rigorous analysis, it provides mechanisms for interpretation and use of wastewater data for public health action, which has been recognized as an ongoing challenge in the field. The alert algorithm is most useful during periods of low transmission, to provide an early warning for new upticks, while the risk estimator may be most useful to assess the extent of spread during an outbreak and determine when all data sources point to waning threat levels.

The significance of these findings are not only applicable for the current Covid-19 pandemic but could also be adapted for other health threats. For example, the logical criteria used to create the Covid-SURGE algorithm could potentially be fine-tuned to develop alert algorithms for flu, polio, or other public health biomarkers being monitored in wastewater.

As the focus on the pandemic wanes with the ending of Covid-19 emergency declarations, the Covid-SURGE algorithm and risk estimator offer public health officials a valuable way to stay vigilant. They provide a timely way to assess when renewed attention and action may be needed, helping to mitigate the impact of future outbreaks, Covid-19 or otherwise.