Paper published on viable bacteria around hospital windows!

In a 2019 collaboration between the Biology and the Built Environment Center at the University of Oregon and the Oregon Health & Sciences University, we sampled various window surfaces from patient rooms in a hospital ward. We characterized the viable bacterial community located on these surfaces, and investigated the association of relative light exposure of the surface (in direct light or not), the cardinal direction of the room (and roughly the amount of total light exposure in a day), and proximity of the patient room to the nurses’ station (which has higher occupancy and traffic).

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Figure 1. Floor plan and rendering of a typical patient room at the Oregon Health and Science University hospital. (a) Floor plan of the 13th floor of Kohler Pavilion (13K) at Oregon Health and Science University (OHSU). Red shading indicates the rooms that were sampled between 10:00 a.m. and 11:00 a.m. on June 7, 2019 (b) Digital rendering of a typical patient room on OHSU (13K) with the sampling locations indicated by the numbers. The sampled locations were (1) window glass surface, (2) the window frame surface facing into the room at the sill, (3) glazing-side of the window frame at the sill, (4) window-side of the curtain, (5) patient-side of the curtain and, (6) wood-covered air return grille.

The microbial community found in buildings is primarily a reflection of the occupants, and in the case of hospitals, the microbiota may be sourced from patients, staff, or visitors. In addition to leaving microbiota behind, occupants may pick up microorganisms from building surfaces. Most of the time, this continuous exchange of microorganisms between a person and their surroundings is unremarkable and does not raise concerns. But in a hospital setting with immunocompromised patients, these microbial reservoirs may pose a risk.  Window glass, sills, and the surfaces around windows are often forgotten during hospital disinfection protocols, and the microbial communities found there have not previously been examined.

This paper is the first first-authored research paper from a former undergraduate mentee of mine at the University of Oregon; Patrick Horve.

Horve, P.F., Dietz, L., Ishaq, S.L., Kline, J., Fretz, M., Van Den Wymelenberg, K. 2020. Viable bacterial communities on hospital window components in patient rooms. PeerJ 8: e9580. Impact 2.353. Article.

2019 review one of Indoor Air’s top downloaded articles for 2018 – 2019!

A collaborative review article that I was last author on was listed in the top 10% most downloaded papers of 208/2019 in the journal Indoor Air! Even more impressive, this review was published August 20, 2019, and it was still in the top 10% spanning from January 2019 – December 2019!!

This paper stems from my work on the microbiology of the built environment at BioBE, and reviews the interaction between chemistry, microbiology, and health in the built environment. It was co-authored and led by undergraduate students I was mentoring at the time, as well as research associates and PIs from the BioBE lab, and a variety of fabulous collaborators!

From one species to another: A review on the interaction between chemistry and microbiology in relation to cleaning in the built environment

Review on ‘health in the built environment’ available online

The review on health in the built environment, led by undergrad (now post-bac) Patrick Horve and which I acted as managing author, is available online here, and an open-access, view-only version is available here.  It’s part of the Healthy Building special issue from the Journal of Exposure Science & Environmental Epidemiology.  

Building upon current knowledge and techniques of indoor microbiology to construct the next era of theory into microorganisms, health, and the built environment. Patrick F. Horve, Savanna Lloyd, Gwynne A. Mhuireach, Leslie Dietz, Mark Fretz, Georgia MacCrone, Kevin Van Den Wymelenberg & Suzanne L. Ishaq.  Journal of Exposure Science & Environmental Epidemiology (2019) 


In the constructed habitat in which we spend up to 90% of our time, architectural design influences occupants’ behavioral patterns, interactions with objects, surfaces, rituals, the outside environment, and each other. Within this built environment, human behavior and building design contribute to the accrual and dispersal of microorganisms; it is a collection of fomites that transfer microorganisms; reservoirs that collect biomass; structures that induce human or air movement patterns; and space types that encourage proximity or isolation between humans whose personal microbial clouds disperse cells into buildings. There have been recent calls to incorporate building microbiology into occupant health and exposure research and standards, yet the built environment is largely viewed as a repository for microorganisms which are to be eliminated, instead of a habitat which is inexorably linked to the microbial influences of building inhabitants. Health sectors have re-evaluated the role of microorganisms in health, incorporating microorganisms into prevention and treatment protocols, yet no paradigm shift has occurred with respect to microbiology of the built environment, despite calls to do so. Technological and logistical constraints often preclude our ability to link health outcomes to indoor microbiology, yet sufficient study exists to inform the theory and implementation of the next era of research and intervention in the built environment. This review presents built environment characteristics in relation to human health and disease, explores some of the current experimental strategies and interventions which explore health in the built environment, and discusses an emerging model for fostering indoor microbiology rather than fearing it.