Georgia WWSCAN biweekly update 7/7/23

Welcome to the bi-weekly update for WWSCAN partners in Georgia! Due to a slight delay since the recent holiday, the samples provided up through 6/29/23 have been processed in the lab and data are on the site at data.wastewaterscan.org.

If you notice any bugs on the site or have any comments about it, please continue to send your feedback via email Amanda Bidwell at albidwel@stanford.edu. We thank you for your partnership!

SARS-CoV-2 N gene RNA concentrations range between 8,000 and 240,000 copies per gram. Click on each chart to further interact with a chart on data.wastewaterscan.org. The dark gray line in the chart below is a population-weighted aggregated trend line for all 8 Georgia sites when the data is normalized by PMMoV. There is additional information on the methodology behind this trend line available here in the "How are aggregated trendlines determined?" section. This chart shows the national levels, and you can see that the average levels have slightly decreased. More details can be found under the "How are national levels determined?" section here.

For most targets, we are also including a trend analysis of their concentrations in wastewater solids (normalized by PMMoV) based on the most recent estimates compared to the recent past. In order to calculate a trend, we require 3 points over the last 21 days. We test for linear trends between log10-transformed concentration (target/PMMoV) and time; the trend must be classified as statistically significant (p<0.1). To read more about our methods for trend analysis click the link here. Analysis of SARS-CoV-2 concentrations across the 8 Georgia sites shows no trend at all sites except Johns Creek, which has seen a significant upward trend.

Early in 2023, WWSCAN started testing for XBB* and these results are available to view by selecting 'SARS-CoV-2 View by Variant' on data.wastewaterscan.org. For Georgia sites, data dates back to early February 2023. The ratio of the XBB* mutations/N across all Georgia plants is shown in the chart below. As the ratio reaches 100%, it suggests that all the SARS-CoV-2 genomes in wastewater have the XBB* mutations. These estimates have not changed much since our last update, and data indicate that the average ratio XBB* mutations/N is ~75% but has ranged from 40-100% recently. This suggests the majority of infections across the communities are caused by XBB*. The next chart below shows the ratio of the BA.5, BA.4, and BQ* mutation/N across all Georgia plants. It can be read the same way as the XBB* chart. The average ratio is close to 0%. Note that our XBB* assay will also detect XBB.1.16, XBB.1.9, and FD.2 (XBB.1.5.15.2*).

Influenza A (IAV) RNA was not detected in samples collected within the last two weeks from all Georgia sites, according to the heat map below and there is no significant trend over the last 21 days at all sites.

Influenza B (IBV) RNA concentrations remain low and are below 6,000 copies/g. Samples collected in the last two weeks detected IBV at RM Clayton and College Park sites. Based on the trend analysis of IBV concentrations normalized by PMMoV at all sites, there is no significant trend over the last 21 days at all sites. This can be interpreted to mean that over the last 21 days, concentrations of IBV RNA have generally not changed at most sites.

RSV RNA detection in the wastewater at Georgia sites has been sporadic, based on the heat map below. Furthermore, the analysis of RSV concentrations across the 8 Georgia sites shows there is no significant trend at all sites over the last 21 days. There was a single positive detection at Utoy Creek last week.

HMPV (human metapneumovirus) RNA concentrations decreased over the last two weeks and are less than 15,000 copies/g. Analysis of HMPV concentrations across the 8 Georgia sites shows no trend at all sites. This can be interpreted to mean that over the last 21 days, concentrations of HMPV have generally not changed at most sites. Below is a chart showing national levels, and you can see that the average level line for all Georgia sites is decreasing and approaching the bottom third boundary.

Norovirus GII (HuNoV GII) RNA concentrations have decreased slightly over the last two weeks and range from 700,000 - 5,000,000 copies/g. The analysis of HuNoV GII concentrations across the 8 Georgia sites shows no trend at all sites over the last 21 days except College Park, which has seen a significant downward trend.

Results remain non-detect for mpox at most Georgia plants. In June, mpox was detected in one sample from the Camp Creek Water Reclamation Facility and one sample at Little River Water Reclamation Facility. This heat map shows data since July 2022. Sites are labeled in the rows and each date a sample was collected as a column. The color blue means the sample was non-detect for mpox DNA and the colors get darker with higher concentrations.

The next stakeholder meeting will take place Friday, July 14th @ 12 PM EST. We hope to see you there!