A 21st century view of infection control in everyday settings: Moving from the Germ Theory of Disease to the Microbial Theory of Health

• Published in: American journal of infection control 2020-11, Vol.48 (11), p.1387-1392
• Main Authors: Scott, Elizabeth A., Bruning, Elizabeth, Nims, Raymond W., Rubino, Joseph R., Ijaz, Mohammad Khalid
• Format: Article
• Language: English
• Subjects: Bidirectional hygiene; Common-touch surfaces; Microbiome; Pathogen transmission; Probiotic cleaner; State of the Science Review; Targeted hygiene; Targeted microbicidal products
• ISSN: 0196-6553; 1527-3296
• DOI: 10.1016/j.ajic.2020.05.012

•We have considered theories on impact of human exposure to nonpathogenic microbes.•A new Microbial Theory of Health is proposed, encouraging targeted hygiene.•Microbiome research and insights from Bidirectional Hygiene inform targeted hygiene. The growing understanding of the importance of a healthy microbiome is challenging traditional thinking that resulted in the general acceptance of the Germ Theory of Disease. We propose a more encompassing Microbial Theory of Health that will have implications for the way that we address our relationship with microbes, including hygiene policy and community-based infection control practices. This paper considers theories over the last 30 years that have impacted hygiene policy and consumer practice, from the Germ Theory of Disease and the Hygiene Hypothesis, to the Microbial Theory of Health, including the concept of Bidirectional Hygiene. Here we present a high-level review of the literature on pathogen transmission and the cycle of infection in the home and everyday settings. Targeted hygiene is an evidence-based hygiene policy that is employed to prevent transmission of pathogens and the transmission of infectious diseases through targeting only sites, surfaces, and practices that are considered high risk for pathogen transmission. Targeted hygiene also discourages the indiscriminate use of broad-spectrum microbicides for lower-risk activities and surfaces. The Microbial Theory of Health, including age-appropriate and health-appropriate hygiene practices for home and everyday life, should usher in a new era in which pathogen reduction can be accomplished without indiscriminate elimination of potentially beneficial microbes from the human and environmental microbiomes.