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Wastewater (sewage) can be tested to detect traces of infectious diseases circulating in a community, even if people don’t have symptoms. You can use these data as an early warning that levels of infections may be increasing or decreasing in your community.
COVID-19 Variants in Wastewater
COVID-19 Wastewater Monitoring in the U.S.
This chart shows the average relative proportions of SARS-COV-2 virus variants in wastewater at the national level. Variants constituting less than 5% abundance are categorized as “Other.”
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All lineages not enumerated in this graphic are aggregated with their parent lineages, based on Pango statement of nomenclature rules.
This chart shows proportions of SARS-CoV-2 variants and sublineages in wastewater over time for contributing wastewater treatment plants with reported sequencing data by collection week. Variant proportions are calculated for each sequenced sample and then averaged nationally. Lineages that make up less than 5% of circulating lineages nationally are categorized as ‘Other’ for the week. These data are not from clinical specimens, but this information complements other systems used to track the emergence and prevalence of variants in US communities. See Summary of Variant Surveillance on COVID Data Tracker for more information.
Predominant variant refers to the most abundant variant collected during the week that was three weeks before the current one, to allow for lags in sequencing. Data from the most recent weeks may be incomplete due to delays in data reporting, and the proportions for previous weeks may change as more data are reported. Certain geographic areas have a higher density of sampling sites, limiting the ability to generalize these results regionally or nationally.
For more information about the data, see Data Methods.
