Over the course of the Progressive Era, revised scientific accounts of the connections between dust, germs, and disease recast debates over public health. The American School of Home Economics and other institutions affiliated with the emerging subfield of household bacteriology regarded detecting and eliminating pathogens as necessary means to achieve safer homes and communities. Although several historians have attributed the rise of early twentieth-century technocracy and the decline of grassroots health activism to germ theory, household bacteriology complicates this standard narrative. (...) Educators like Sophronia Maria Elliott (1854–1942) rejected the command-and-control tactics of the “new” public health and instead instructed women how to culture microorganisms and to measure the risks of infection within their surrounding environments using kitchen experiments. Household bacteriologists aspired to train “sanitary citizens” with the right and the duty to test for germs with everyday equipment, to prevent disease with effective housekeeping, and to advocate for policies and infrastructure to keep society well. (shrink)