Counties from three US States in the Navajo Nation with percent Navajo population and COVID-19 case attributes.

Wastewater-based epidemiology is a promising public health tool that can yield a more representative view of the population than case reporting. However, only about 80% of the U.S. population is connected to public sewers, and the characteristics of populations missed by wastewater-based epidemiology are unclear. To address this gap, we used publicly available datasets to assess sewer connectivity in the U.S. by location, demographic groups, and economic groups. Data from the U.S. Census’ American Housing Survey revealed that sewer connectivity was lower than average when the head of household was American Indian and Alaskan Native, White, non-Hispanic, older, and for larger households and those with higher income, but smaller geographic scales revealed local variations from this national connectivity pattern. For example, data from the U.S. Environmental Protection Agency showed that sewer connectivity was positively correlated with income in Minnesota, Florida, and California. Data from the U.S. Census’ American Community Survey and Environmental Protection Agency also revealed geographic areas with low sewer connectivity, such as Alaska, the Navajo Nation, Minnesota, Michigan, and Florida. However, with the exception of the U.S. Census data, there were inconsistencies across datasets. Using mathematical modeling to assess the impact of wastewater sampling inequities on inferences about epidemic trajectory at a local scale, we found that in some situations, even weak connections between communities may allow wastewater monitoring in one community to serve as a reliable proxy for an interacting community with no wastewater monitoring, when cases are widespread. A systematic, rigorous assessment of sewer connectivity will be important for ensuring an equitable and informed implementation of wastewater-based epidemiology as a public health monitoring system.

The TIGER/Line shapefiles and related database files (.dbf) are an extract of selected geographic and cartographic information from the U.S. Census Bureau's Master Address File / Topologically Integrated Geographic Encoding and Referencing (MAF/TIGER) Database (MTDB). The MTDB represents a seamless national file with no overlaps or gaps between parts, however, each TIGER/Line shapefile is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. American Indian tribal subdivisions are administrative subdivisions of federally recognized American Indian reservations/off-reservation trust lands or Oklahoma tribal statistical areas (OTSAs). These entities are internal units of self-government and/or administration that serve social, cultural, and/or economic purposes for the American Indian tribe or tribes on the reservations/off-reservation trust lands or OTSAs. The Census Bureau obtains the boundary and attribute information for tribal subdivisions on federally recognized American Indian reservations and off-reservation trust lands from federally recognized tribal governments through the Census Bureau's Boundary and Annexation Survey (BAS). For the 2020 Census, the boundaries for tribal subdivisions on OTSAs were also obtained from federally recognized tribal governments through the Participant Statistical Areas Program (PSAP). Note that tribal subdivisions do not exist on all reservations/off-reservation trust lands or OTSAs, rather only where they were submitted to the Census Bureau by the federally recognized tribal government for that area. The boundaries for American Indian tribal subdivisions are as of January 1, 2020, as reported by the federally recognized tribal governments through the Census Bureau's Boundary and Annexation Survey (BAS). The boundaries for tribal subdivisions on OTSAs are those reported as of January 1, 2020 through PSAP.

Correlation of the percentage of a Florida county subdivision not connected to septic tanks with different demographic or economic variables.