Engineering Infection Controls to Reduce Indoor Transmission of Respiratory Infections

Engineering infection controls include a wide range of interventions used indoors to reduce occupants' exposure to respiratory pathogens. To identify and describe primary studies evaluating the effects of engineering infection control interventions designed to reduce the spread of respiratory infections transmitted through indoor air. MEDLINE, Embase, Global Health, Cochrane Central Register of Controlled Trials, CINAHL, Scopus, and Environmental Science Collection from database inception to 12 December 2023. English-language primary research articles evaluating engineering infection control interventions. Publication information, population characteristics, intervention details, and all relevant outcomes were abstracted by a reviewer and verified by a second, senior reviewer. A total of 672 studies published between 1929 and 2024 were identified. Most (n = 606) evaluated environmental samples only, 57 included human participants, and 9 included sentinel animal subjects. About half of the studies included at least 1 intervention classified as pathogen inactivation (n = 405), with fewer involving pathogen removal (n = 200) or air exchange or dilution (n = 143). Across all studies, about half (n = 332) measured the quantity of viable nonpathogenic organisms from air samples, followed by the quantity of nonbiological particulates (n = 197) or viable pathogenic organisms (n = 149). Harms, such as toxic byproducts, were rarely measured. Exclusion of non-English-language publications and gray literature. There is substantial heterogeneity in the available evidence. Gaps in evidence include studies measuring efficacy outcomes that are highly relevant for human infection transmission or harms. Refinements in classification of interventions and outcomes could strengthen reporting of these evaluations. National Institute for Occupational Safety and Health at the Centers for Disease Control and Prevention. (Registered on Open Science Framework https://osf.io/5zmhd).