They continue to aggregate the data by calculating a z-score, and normalizing to a rolling one-year baseline, before aggregation. Thus the WVAL is still not proportional to RNA copies detected, but rather a number which reflects recent trends. 3/
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The change to non-normalized data *might* make sense given that they are interested in producing a number that tracks trends in wastewater RNA. It removes any trend that might be present due to changes in the normalization (e.g. seasonal changes in PMMoV). 4/
aug 16, 2025, 12:37 am • 4 0 • view
Practically though, it appears to have increased the short-time fluctuations in the data. Which probably makes it less useful for detecting changes in the recent trend. So I am a bit surprised that they made the change. 5/5
aug 16, 2025, 12:37 am • 5 1 • view