Current views of health care design and construction: Practical implications for safer, cleaner environments

Infection preventionists (IP) play an increasingly important role in preventing health care-associated infection in the physical environment associated with new construction or renovation of health care facilities. The Guidelines for Design and Construction of Hospital and Healthcare Facilities, 2010, formerly known as ''AIA Guidelines'' was the origin of the ''infection control risk assessment'' now required by multiple agencies. These Guidelines represent minimum US health care standards and provide guidance on best practices. They recognize that the built environment has a profound affect on health and the natural environment and require that health care facilities be designed to ''first, do no harm.'' This review uses the Guidelines as a blueprint for IPs' role in design and construction, updating familiar concepts to the 2010 edition with special emphasis on IP input into design given its longer range impact on health care-associated infection prevention while linking to safety and sustainability. Section I provides an overview of disease transmission risks from the built environment and related costs, section II presents a broad view of design and master planning, and section III addresses the detailed design strategies for infection prevention specifically addressed in the 2010 Facility Guidelines Institute edition. Key Words: Health care design; construction; ventilation; water quality; operating room design; sustainability. INTRODUCTION Infection preventionists (IP) are integral members of the team of professionals who design, construct, operate, and work in health care facilities. IP's subject matter expertise on prevention of cross transmission and design/operations of facilities aimed at safety of all occupants in the built environment initially led to the foundation of the infection control risk assessment (ICRA) process. The ICRA grew out of concern related to increasing reports of health care-associated infections (HAIs) caused by construction/renovation in facilities. Details of this have been reviewed elsewhere. 2 This forecast plus increasing focus on prevention of HAIs are key developments that will call on continued expansion of the IP's scope of practice. 3 This scope will include oversight of containment of microorganisms and contaminants under the ICRA but increasingly emphasize more proactive involvement in design of the environment of care (EoC) from concept to occupancy. 4 This review will focus on the IP's expanding role in the development and operations of the built environment in the 21st century. OVERVIEW OF DISEASE TRANSMISSION RISKS FROM THE BUILT ENVIRONMENT Disease transmission risks Air. Although the actual percentage of HAIs directly related to construction is unknown, the morbidity, mortality, and costs of mitigation are considerable. Vonberg and Gastmeier reviewed outbreaks of infection caused by Aspergillus spp and found that almost half were associated with construction or renovation in hospitals. 5 In addition, a dose of only 1 colony forming unit/m 3 was needed to cause infection in immunocompromised patients and highlights the critical need for isolation and containment of construction activities from other occupied spaces. Other pathogens transmitted during Water. The reservoir of microbes of pathogens present in potable water and its delivery network are vast. These include gram-negative bacteria, eg, Legionellae and Pseudomonas spp, nontuberculous Mycobacteria, protozoa, and fungi. 8 Disruption of water utility systems during construction or renovation can disrupt the biofilm present in water delivery pipes, posing a threat to patients, including those far away from an active construction zone. Environmental surfaces and patient care equipment. The relative importance of the inanimate environment as a reservoir of organisms has undergone renewed emphasis, given the emergence of a wide range of microorganisms including multidrug-resistant organisms (MDROs) present in health care settings. Presence of MDROs on surfaces that appear relatively clean and transfer of these on hands of personnel has been described. The bioburden of an inpatient room has been studied given the concern over environmental reservoirs of MDROs. Huang et al found admission to a room previously occupied by a patient with MDROs increases the likelihood of acquisition of these organisms by subsequent patients. 14 More recently, Hamel et al describe increased risk of acquisition and cross infection of 2 key MDROs and Clostridium difficile to roommates in multibed patient rooms. 15 Equipment and devices used to support electronic health records can also become contaminated with microbes; however, Lu et al demonstrated that the concentration of this contamination is low and often unrelated to strains recovered from patients. Construction trends and changes in health care delivery in US hospitals Annual construction and design cost. United States trends indicate a continued major expenditure in health care construction and renovation even with economic downturn in [2008][2009]. Changes in patient acuity, aging, and reduced capitol funds have affected construction expenditures in a number of ways. Recent trends show that dollars are spent primarily on inpatient specialty beds (eg, cardiac and cancer) along with increasing demands for assisted-living and skilled nursing centers. Construction for hospitals and clinics in the fourth quarter of 2008 totaled $40.7 billion with three quarters of projects involving either expansion or renovation. 17 Interestingly, among the top 5 design features incorporated into patient room design was an in-room handwashing sink (almost 50% of new construction), separate from that in the bathroom attached to the room. Looking ahead, there will likely be a stabilization in construction activities with modest growth as noted earlier, but the economic constrains may lead to a drop in the total square footage of built environment for the next several years. Planning for future needs. The increasing age of US health care facilities generates a constant need for repair, remediation work (cabling, room additions), or replacement. These processes increase risks of environmental contamination, affecting air and water quality and sustainability. Planning for surge capacity. Planning for surge capacity needed for potential airborne infectious agent releases or a major influx of patients with communicable disease such as an influenza pandemic is also challenging with increased numbers of single or variable acuity patient rooms. Some institutions include extra utilities, so some rooms, including ICUs, have essentially 2 head walls with duplicate utilities needed for such critical circumstances that could require 2 patients in each room. DESIGN AND MASTER PLANNING SAFETY AND INFECTION PREVENTION Design layout trends New elements being incorporated into design and master planning of health care facility construction S2 Bartley, Olmsted, and Haas Designs aimed at environmental sustainability are also being used in over 80% of active projects based on a survey from 2008, and this is likely to continue. 2 These green design features include enhanced efficiency of heating, ventilation, and air conditioning (HVAC) systems; building utilities (power and water); surface and finish treatments that lessen use of volatile organic compounds; and use of natural lighting, lowemission glass, and waste reclamation. Contractors frequently reclaim/recycle materials produced during demolition. Addressing economic challenges while maintaining quality and safety of patient care has led to increasing use of Six Sigma Lean methods and principles. The goal of Lean is to create maximum value for patients by reducing waste through improved quality, efficiency, and safety. It employs a range of performance assessment and improvement tools and depends heavily on datadriven decision making. Lean principles have been adopted widely by health care planners and are increasingly making an impact on design of the built environment, supporting the goal of increased efficiency and waste elimination

Quantitative imaging of concentrated suspensions under flow

We review recent advances in imaging the flow of concentrated suspensions, focussing on the use of confocal microscopy to obtain time-resolved information on the single-particle level in these systems. After motivating the need for quantitative (confocal) imaging in suspension rheology, we briefly describe the particles, sample environments, microscopy tools and analysis algorithms needed to perform this kind of experiments. The second part of the review focusses on microscopic aspects of the flow of concentrated model hard-sphere-like suspensions, and the relation to non-linear rheological phenomena such as yielding, shear localization, wall slip and shear-induced ordering. Both Brownian and non-Brownian systems will be described. We show how quantitative imaging can improve our understanding of the connection between microscopic dynamics and bulk flow.Comment: Review on imaging hard-sphere suspensions, incl summary of methodology. Submitted for special volume 'High Solid Dispersions' ed. M. Cloitre, Vol. xx of 'Advances and Polymer Science' (Springer, Berlin, 2009); 22 pages, 16 fig

Transcriptional Regulator PerA Influences Biofilm-Associated, Platelet Binding, and Metabolic Gene Expression in Enterococcus faecalis

Enterococcus faecalis is an opportunistic pathogen and a leading cause of nosocomial infections, traits facilitated by the ability to quickly acquire and transfer virulence determinants. A 150 kb pathogenicity island (PAI) comprised of genes contributing to virulence is found in many enterococcal isolates and is known to undergo horizontal transfer. We have shown that the PAI-encoded transcriptional regulator PerA contributes to pathogenicity in the mouse peritonitis infection model. In this study, we used whole-genome microarrays to determine the PerA regulon. The PerA regulon is extensive, as transcriptional analysis showed 151 differentially regulated genes. Our findings reveal that PerA coordinately regulates genes important for metabolism, amino acid degradation, and pathogenicity. Further transcriptional analysis revealed that PerA is influenced by bicarbonate. Additionally, PerA influences the ability of E. faecalis to bind to human platelets. Our results suggest that PerA is a global transcriptional regulator that coordinately regulates genes responsible for enterococcal pathogenicity

Synergistic Actions of Hematopoietic and Mesenchymal Stem/Progenitor Cells in Vascularizing Bioengineered Tissues

Poor angiogenesis is a major road block for tissue repair. The regeneration of virtually all tissues is limited by angiogenesis, given the diffusion of nutrients, oxygen, and waste products is limited to a few hundred micrometers. We postulated that co-transplantation of hematopoietic and mesenchymal stem/progenitor cells improves angiogenesis of tissue repair and hence the outcome of regeneration. In this study, we tested this hypothesis by using bone as a model whose regeneration is impaired unless it is vascularized. Hematopoietic stem/progenitor cells (HSCs) and mesenchymal stem/progenitor cells (MSCs) were isolated from each of three healthy human bone marrow samples and reconstituted in a porous scaffold. MSCs were seeded in micropores of 3D calcium phosphate (CP) scaffolds, followed by infusion of gel-suspended CD34+ hematopoietic cells. Co-transplantation of CD34+ HSCs and CD34− MSCs in microporous CP scaffolds subcutaneously in the dorsum of immunocompromized mice yielded vascularized tissue. The average vascular number of co-transplanted CD34+ and MSC scaffolds was substantially greater than MSC transplantation alone. Human osteocalcin was expressed in the micropores of CP scaffolds and was significantly increased upon co-transplantation of MSCs and CD34+ cells. Human nuclear staining revealed the engraftment of transplanted human cells in vascular endothelium upon co-transplantation of MSCs and CD34+ cells. Based on additional in vitro results of endothelial differentiation of CD34+ cells by vascular endothelial growth factor (VEGF), we adsorbed VEGF with co-transplanted CD34+ and MSCs in the microporous CP scaffolds in vivo, and discovered that vascular number and diameter further increased, likely owing to the promotion of endothelial differentiation of CD34+ cells by VEGF. Together, co-transplantation of hematopoietic and mesenchymal stem/progenitor cells may improve the regeneration of vascular dependent tissues such as bone, adipose, muscle and dermal grafts, and may have implications in the regeneration of internal organs

Comparative Genomic Analysis of Pathogenic and Probiotic Enterococcus faecalis Isolates, and Their Transcriptional Responses to Growth in Human Urine

Urinary tract infection (UTI) is the most common infection caused by enterococci, and Enterococcus faecalis accounts for the majority of enterococcal infections. Although a number of virulence related traits have been established, no comprehensive genomic or transcriptomic studies have been conducted to investigate how to distinguish pathogenic from non-pathogenic E. faecalis in their ability to cause UTI. In order to identify potential genetic traits or gene regulatory features that distinguish pathogenic from non-pathogenic E. faecalis with respect to UTI, we have performed comparative genomic analysis, and investigated growth capacity and transcriptome profiling in human urine in vitro. Six strains of different origins were cultivated and all grew readily in human urine. The three strains chosen for transcriptional analysis showed an overall similar response with respect to energy and nitrogen metabolism, stress mechanism, cell envelope modifications, and trace metal acquisition. Our results suggest that citrate and aspartate are significant for growth of E. faecalis in human urine, and manganese appear to be a limiting factor. The majority of virulence factors were either not differentially regulated or down-regulated. Notably, a significant up-regulation of genes involved in biofilm formation was observed. Strains from different origins have similar capacity to grow in human urine. The overall similar transcriptional responses between the two pathogenic and the probiotic strain suggest that the pathogenic potential of a certain E. faecalis strain may to a great extent be determined by presence of fitness and virulence factors, rather than the level of expression of such traits