Data from reported numbers of positive RT-qPCR tests and reported numbers of death cases were compared to the number of viral particles in wastewater in Bratislava and visualized in the following figures.

Figure 1. The blue curve is our measured data from wastewater with a peak in the middle of December. The green curve visualizes reported fatalities from each day, with the highest number of fatalities in the middle of January. Solely from the data, we can observe a one-month time shift between the peaks from each curve. This dependence for weekly time series was supported mathematically by a double squared root regression model with 83,21% correlation.
Figure 2. The figure is analogical to the Figure 1, but here we focused on the time shifts between the number of viral particles in the water and positive PCR tests. The data displays the correlation highest when we focused on 2 weeks time lag. In this case when using the double squared root regression model we obtained 83,78% fit between the middle of December (blue curve) and the end of December (red curve).
Figure 3. The figure is an overlay of the Figure 2, where it can be seen that wastewater analysis is the first one reaching maximum following PCR tests and fatalities. It can be noticed that all 3 curves display similar trends during the monitored period from September 2020 to March 2021.