datum (n=1)<p><span class="h-card" translate="no"><a href="https://mastodon.social/@augieray" class="u-url mention" rel="nofollow noopener" target="_blank">@<span>augieray</span></a></span> </p><blockquote><p>2) People saying wastewater data isn't accurate.</p></blockquote><p>Wastewater is accurate <em>day-to-day</em>. It <em>may not</em> be accurate <em>variant-to-variant</em>, and is certainly expected to vary within a given person by their vaccination and infection history. Support:</p><blockquote><p>it remains challenging to directly translate wastewater SARS-CoV-2 viral loads to a specific number of infections in the population, due to the unclear fecal viral shedding rate (after accounting for the recovery rate of virus genomes) in wastewater samples. [4]</p></blockquote><p>Eg:</p><blockquote><p>In wastwater [...] Delta [...] had the highest mean shedding rates [...] while Omicron, exhibiting reduced symptoms, had the lowest mean shedding rates [1]</p></blockquote><p>and</p><blockquote><p>monovalent vaccination modified the time course and viral load of infections from different variants [2]</p></blockquote><p>and</p><blockquote><p>viral shedding duration differed significantly between BA.4/5 and BF.7 groups (p < 0.0001). [3]</p></blockquote><p>and</p><blockquote><p>Estimated fecal viral shedding rate was highest during the ancestral/Iota variant wave, at 1.44 (95% CI: 1.35 – 1.53) billion RNA copies in wastewater per day per infection (measured by RT-qPCR), and decreased by around 20% and 50-60% during the Delta wave and Omicron period, respectively. [4]</p></blockquote><p>Which I take to mean that because of variant soup right now, and limited evidence specific to each variant (and kinetics and escape) and to immune histories (and waning), that we cannot translate directly from wastewater to case count. It is quite plausible to imagine, for example, a variant with half the fecal shedding taking over and causing wastewater to decline while cases increase - or with twice the fecal shedding taking over and causing wastewater levels to go up while cases drop.</p><p>[1] <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC9527179/" rel="nofollow noopener" translate="no" target="_blank"><span class="invisible">https://</span><span class="ellipsis">pmc.ncbi.nlm.nih.gov/articles/</span><span class="invisible">PMC9527179/</span></a> </p><p>[2] <a href="https://www.sciencedirect.com/science/article/pii/S0163445323005479" rel="nofollow noopener" translate="no" target="_blank"><span class="invisible">https://www.</span><span class="ellipsis">sciencedirect.com/science/arti</span><span class="invisible">cle/pii/S0163445323005479</span></a></p><p>[3] <a href="https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2024.1478466/full" rel="nofollow noopener" translate="no" target="_blank"><span class="invisible">https://www.</span><span class="ellipsis">frontiersin.org/journals/medic</span><span class="invisible">ine/articles/10.3389/fmed.2024.1478466/full</span></a></p><p>[4] <a href="https://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-025-22306-1" rel="nofollow noopener" translate="no" target="_blank"><span class="invisible">https://</span><span class="ellipsis">bmcpublichealth.biomedcentral.</span><span class="invisible">com/articles/10.1186/s12889-025-22306-1</span></a></p><p><a href="https://zeroes.ca/tags/COVID19" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>COVID19</span></a> <a href="https://zeroes.ca/tags/COVID" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>COVID</span></a> <a href="https://zeroes.ca/tags/SARSCoV2" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>SARSCoV2</span></a> <a href="https://zeroes.ca/tags/CovidIsNotOver" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>CovidIsNotOver</span></a> <a href="https://zeroes.ca/tags/MaskUp" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>MaskUp</span></a> <a href="https://zeroes.ca/tags/cleanAir" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>cleanAir</span></a> <a href="https://zeroes.ca/tags/publicHealth" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>publicHealth</span></a> <a href="https://zeroes.ca/tags/wastewater" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>wastewater</span></a> <a href="https://zeroes.ca/tags/AirborneAware" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>AirborneAware</span></a> <a href="https://zeroes.ca/tags/CovidCompetent" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>CovidCompetent</span></a></p>