Hospital and community acquired infection and the built environment--design and testing of infection control rooms

A Blockchain-Based Life-Cycle Environmental Management Framework for Hospitals in the COVID-19 Context

During the coronavirus disease 2019 (COVID-19) emergency, many hospitals were built or renovated around the world to meet the challenges posed by the rising number of infected cases. Environmental management in the hospital life cycle is vital in preventing nosocomial infection and includes many infection control procedures. In certain urgent situations, a hospital must be completed quickly, and work process approval and supervision must therefore be accelerated. Thus, many works cannot be checked in detail. This results in a lack of work liability control and increases the difficulty of ensuring the fulfillment of key infection prevention measures. This study investigates how blockchain technology can transform the work quality inspection workflow to assist in nosocomial infection control under a fast delivery requirement. A blockchain-based life-cycle environmental management framework is proposed to track the fulfillment of crucial infection control measures in the design, construction, and operation stages of hospitals. The proposed framework allows for work quality checking after the work is completed, when some work cannot be checked on time. Illustrative use cases are selected to demonstrate the capabilities of the developed solution. This study provides new insights into applying blockchain technology to address the challenge of environmental management brought by rapid delivery requirements.

Reducing the risk of viral contamination during the coronavirus pandemic by using a protective curtain in the operating room

Background

Airborne transmission diseases can transfer long and short distances via sneezing, coughing, and breathing. These airborne repertory particles can convert to aerosol particles and travel with airflow. During the Coronavirus disease 2019 (COVID-19) pandemic, many surgeries have been delayed, increasing the demand for establishing a clean environment for both patient and surgical team in the operating room.

Methods

This study aims to investigate the hypothesis of implementing a protective curtain to reduce the transmission of infectious contamination in the surgical microenvironment of an operating room. In this regard, the spread of an airborne transmission disease from the patient was evaluated, consequently, the exposure level of the surgical team. In the first part of this study, a mock surgical experiment was established in the operating room of an academic medical center in Norway. In the second part, the computational fluid dynamic technique was performed to investigate the spread of airborne infectious diseases. Furthermore, the field measurement was used to validate the numerical model and guarantee the accuracy of the applied numerical models.

Results

The results showed that the airborne infectious agents reached the breathing zone of the surgeons. However, using a protective curtain to separate the microenvironment between the head and lower body of the patient resulted in a 75% reduction in the spread of the virus to the breathing zone of the surgeons. The experimental results showed a surface temperature of 40 ˚C, which was about a 20 ˚C increase in temperature, at the wound area using a high intensity of the LED surgical lamps. Consequently, this temperature increase can raise the patient's thermal injury risk.

Conclusion

The novel method of using a protective curtain can increase the safety of the surgical team during the surgery with a COVID-19 patient in the operating room.

Influenza cases in nine aged care facilities in Sydney, Australia over a three-year surveillance period, 2018-2020

BACKGROUND

Influenza outbreaks in aged care facilities are a major public health concern. In response to the severe 2017 influenza season in Australia, enhanced influenza vaccines were introduced from 2018 onwards for those over 65 and more emphasis was placed on improving vaccination rates among aged care staff. During the COVID-19 pandemic, these efforts were then further escalated to reduce the additional burden that influenza could pose to facilities.

METHODS

An observational epidemiological study was conducted from 2018 to 2020 in nine Sydney (Australia) aged care facilities of the same provider. De-identified vaccination data and physical layout data were collected from participating facility managers from 2018 to 2020. Active surveillance of influenza-like illness was carried out from 2018 to 2020 influenza seasons. Correlation and Poisson regression analyses were carried out to explore the relationship between physical layout variables to occurrence of influenza cases.

RESULTS

Influenza cases were low in 2018 and 2019, and there were no confirmed influenza cases identified in 2020. Vaccination rates increased among staff by 50.5% and residents by 16.8% over the three-year period of surveillance from 2018 to 2020. For each unit increase in total number of beds, common areas, single rooms, all types of rooms (including double occupancy rooms), the influenza cases increased by 1.02 (95% confidence interval:1.018-1.025), 1.04 (95% confidence interval: 1.019-1.073), 1.03 (95% confidence interval: 1.016-1 0.038) and 1.02 (95% confidence interval:1.005-1.026) times which were found to be statistically significant. For each unit increase in the proportion of shared rooms, influenza cases increased by 1.004 (95% confidence interval:1.0001-1.207) which was found to be statistically significant.

CONCLUSIONS

There is a relationship between influenza case counts and aspects of the physical layout such as facility size, and this should be considered in assessing risk of outbreaks in aged care facilities. Increased vaccination rates in staff and COVID-19 prevention and control measures may have eliminated influenza in the studied facilities in 2020.

Investigation of airborne particle exposure in an office with mixing and displacement ventilation

Effective ventilation could reduce COVID-19 infection in buildings. By using a computational fluid dynamics technique and advanced experimental measurement methods, this investigation studied the air velocity, air temperature, and particle number concentration in an office under a mixing ventilation (MV) system and a displacement ventilation (DV) system with different ventilation rates. The results show reasonably good agreement between the computed results and measured data. The air temperature and particle number concentration under the MV system were uniform, while the DV system generated a vertical stratification of the air temperature and particle number concentration. Because of the vertical stratification of the particle number concentration, the DV system provided better indoor air quality than the MV system. An increase in ventilation rate can reduce the particle concentration under the two systems. However, the improvement was not proportional to the ventilation rate. The increase in ventilation rate from 2 ACH to 4 ACH and 6 ACH for MV system reduced the particle concentration by 20% and 60%, respectively. While for the DV system, increasing the ventilation rate from 2 ACH to 4 ACH and 6 ACH reduced the particle concentration by only 10% and 40%, respectively. The ventilation effectiveness of the MV system was close to 1.0, but it was much higher for the DV system. Therefore, the DV system was better than the MV system.

Nurses' Perception of Safety on Hospital Interior Environments and Infectious Diseases: An Exploratory Study

Introduction

Healthcare environments consist of a variety of different fomites containing infectious agents. From the 2003 outbreaks of Severe Acute Respiratory Syndrome to the recent concerns about the Ebola and Zika viruses, interest in the role of healthcare environment fomites in spreading infectious diseases has increased. Because of a high risk of being exposed to infections, the goal of this study was to learn how hospital interior environments impact nurses' perceptions of safety about infectious diseases.

Methods

Semistructured, in-depth interviews were conducted with six nurses at a public hospital.

Results

The following three themes were identified: (1) perceptions of safety from infectious diseases were diverse among the participants; (2) various interior environments in hospital settings can prevent as well as promote the spreading of infectious diseases; and (3) the different perceptions influenced the ways participants developed their contrasting behaviors of treating interior environments to cope with their fears (e.g., how they open doors).

Conclusion

The findings from this study contribute to the existing body of knowledge on designing hospital interior environments to better understand nurses' perception of infectious diseases.

Cartography of opportunistic pathogens and antibiotic resistance genes in a tertiary hospital environment

Although disinfection is key to infection control, the colonization patterns and resistomes of hospital-environment microbes remain underexplored. We report the first extensive genomic characterization of microbiomes, pathogens and antibiotic resistance cassettes in a tertiary-care hospital, from repeated sampling (up to 1.5 years apart) of 179 sites associated with 45 beds. Deep shotgun metagenomics unveiled distinct ecological niches of microbes and antibiotic resistance genes characterized by biofilm-forming and human-microbiome-influenced environments with corresponding patterns of spatiotemporal divergence. Quasi-metagenomics with nanopore sequencing provided thousands of high-contiguity genomes, phage and plasmid sequences (>60% novel), enabling characterization of resistome and mobilome diversity and dynamic architectures in hospital environments. Phylogenetics identified multidrug-resistant strains as being widely distributed and stably colonizing across sites. Comparisons with clinical isolates indicated that such microbes can persist in hospitals for extended periods (>8 years), to opportunistically infect patients. These findings highlight the importance of characterizing antibiotic resistance reservoirs in hospitals and establish the feasibility of systematic surveys to target resources for preventing infections.

Spatiotemporal characterization of microbial diversity and antibiotic resistance in a tertiary-care hospital reveals broad distribution and persistence of antibiotic-resistant organisms that could cause opportunistic infections in a healthcare setting.

Impact of air-handling system exhaust failure on dissemination pattern of simulant pathogen particles in a clinical biocontainment unit

Biocontainment units (BCUs) are facilities used to care for patients with highly infectious diseases. However, there is limited guidance on BCU protocols and design. This study presents the first investigation of how HVAC (heating, ventilation, air-conditioning) operating conditions influence the dissemination of fluorescent tracer particles released in a BCU. Test conditions included normal HVAC operation and exhaust failure resulting in loss of negative pressure. A suspension of optical brightener powder and water was nebulized to produce fluorescent particles simulating droplet nuclei (0.5-5 μm). Airborne particle number concentrations were monitored by Instantaneous Biological Analyzers and Collectors (FLIR Systems). During normal HVAC operation, fluorescent tracer particles were contained in the isolation room (average concentration = 1 × 10⁴ ± 3 × 10³ /L_air ). Under exhaust failure, the automated HVAC system maximizes airflow into areas adjacent to isolation rooms to attempt to maintain negative pressure differential. However, 6% of the fluorescent particles were transported through cracks around doors/door handles out of the isolation room via airflow alone and not by movement of personnel or doors. Overall, this study provides a systematic method for evaluating capabilities to contain aerosolized particles during various HVAC scenarios. Recommendations are provided to improve situation-specific BCU safety.

General Information

Many bacteria, viruses, parasites, fungi and prions may cause serious infections and lead to the isolation of those who are infected from those who are susceptible. Isolation may be done in single rooms or in special isolation units. A modern isolate for patients with infections comprises (1) a sluice with a good space for dressing and undressing of personal protective equipment (PPE) and for hand hygiene, (2) a large patient room and (3) a bathroom/disinfection room with own decontaminator or autoclave and with separate entrance from the patient’s room. Isolates for airborne and droplet-transmitted infections have in addition a defined negative air pressure and hepafiltered exhaust. In all isolates, doors must be closed in such a way that contaminants do not escape the isolate. A modern isolate for patients with impaired immune defence is similar to the infection isolates, with following exceptions: usually no need for decontaminator, hepafiltered clean air into the room and with a defined positive air pressure. A positive pressure isolate should never be used for patients with infections, and a negative pressure isolate should never be used for patients with impaired immune defence, except if the patient also has an infection that needs isolation.

Design and Simulation of Isolation Room for a Hospital

Heating, ventilation and air conditioning (HVAC) of hospitals is a highly specialized field and critical care units like isolation rooms and operation theatres deserve special attention, as infected patients must be isolated from ambient environment in order to prevent the infection from spreading and to save the life of the patient. This manuscript aims to optimize the ventilation strategy towards contaminant suppression in the isolation room. 3D Navier-Stokes and energy equation using finite volume method (FVM) with a domain of isolation room is solved for appropriate boundary conditions. The patient’s body is approximated as a semi-cylindrical shape resting on a bed and is treated as a constant heat source. Velocity and temperature profile inside the isolation room for various configurations are simulated. Our results suggest that immune-suppressed patients should be kept near the air supply and infectious patients near the exhaust.

Strict Isolation

Strict isolation: suspected highly infectious and transmissible virulent and pathogenic microbes, highly resistant bacterial strains and agents that are not accepted in any form of distribution in the society or in the environment. Examples are completely resistant Mycobacterium tuberculosis, viral haemorrhagic fevers like Ebola and Lassa, pandemic severe influenza and coronavirus like SARS, MERS, etc. In most countries, strict isolation is a rarely used isolation regime but should be a part of the national preparedness plan. For instance, in Norway, strict isolation has not been used for the last 50–60 years, except for one case of imported Ebola infection in 2014. Patients in need of strict isolation should be placed in a separate isolation ward or building.

Infection spread by contact, droplet and airborne infection, aerosols, re-aerosols, airborne microbe-carrying particles, skin cells, dust, droplets and droplet nuclei. At the same time, it is always contact transmission (contaminated environment, equipment, textiles and waste).

The source of infection is usually a patient but may also be a symptomless carrier or a zoonotic disease.

Background Information: Isolation Routines

The isolation of patients with suspected or documented infections—to not spread to others—has been discussed for hundreds of years. Guidelines are many, methods are different, attitudes show vide variations, routines and procedures are still changing, regulations by law may be absent, and some healthcare professionals may be afraid of adverse outcomes of isolation [1–44]. Microbes that are spread in the environment, on the hands and equipment are invisible. The invisible agent does not call on attention before the infection; clinical disease, hospital infection or nosocomial infection is a factum that can be registered [23, 28, 29, 35–37]. How to stop the transmission is often “to believe and not believe” in infection control.

Airborne/Droplet Infection Isolation

Airborne/droplet infection is caused by infected agents in the air around a person. Microbial pathogenic agents that are mainly transmitted airborne are aerosols, re-aerosols, microbe-carrying particles, huge amounts of bacteria-carrying airborne skin cells, dust, droplets and droplet nuclei. At the same time, there is always a contact transmission from contaminated environment, equipment, textiles and waste. Droplet nuclei are small evaporated droplet residues (<5 μm) produced by coughing, sneezing, shouting, singing and speaking very distinct—especially the consonants. Droplet nuclei remain for many hours in the air and may be carried by normal air currents in long distances outside the room. Therefore, “droplet isolation and droplet precaution” is included in the airborne isolation regime. The source of infection is usually a patient but may also be a healthy carrier. The patient should be placed in isolate dedicated for airborne infections.

Assessing the functionality of temporary isolation rooms

BACKGROUND

Challenges with limited single rooms and isolation facilities in hospitals have created an opportunity for temporary, portable isolation technology. This article describes the process used to evaluate the prototype of a new isolation room (RediRoom; CareStrategic Ltd, Brisbane, Queensland, Australia) that can be installed in existing hospital ward areas. Our aim is to assess the functionality of this new room, and in so doing, to evaluate the methods used.

METHODS

We employed a mixed-methods approach involving video recording, interviews, and objective temperature and humidity measurements within a crossover interventional study. Participants completed a range of clinical activities in the RediRoom and a control. The setting for the study was a clinical ward environment at an Australian higher education institution.

RESULTS

There were similarities between the RediRoom and the control using a range of measures. The time taken to complete a range of clinical activities in both rooms was broadly consistent. Network analysis also suggested broad similarities in the movement of nurses undertaking activities in both rooms.

CONCLUSION

Our study attempted to simulate a clinical environment and clinical activities and provide the best possible comparison by completing activities sequentially, with immediate feedback to researchers. Video recording added significant value to the process because it provided some objectivity. A form of reflexive ethnography with participants could be of value in similar studies in the future.

Negative pressure of the environmental air in the cleaning area of the materials and sterilization center: a systematic review

OBJECTIVE

to analyze the scientific evidence on aerosols generated during cleaning activities of health products in the Central Service Department (CSD) and the impact of the negative pressure of the ambient air in the cleaning area to control the dispersion of aerosols to adjacent areas.

METHOD

for this literature systematic review the following searches were done: search guidelines, manuals or national and international technical standards given by experts; search in the portal and databases PubMed, Scopus, CINAHL and Web of Science; and a manual search of scientific articles.

RESULTS

the five technical documents reviewed recommend that the CSD cleaning area should have a negative differential ambient air pressure, but scientific articles on the impact of this intervention were not found. The four articles included talked about aerosols formed after the use of a ultrasonic cleaner (an increased in the contamination especially during use) and pressurized water jet (formation of smaller aerosols 5μm). In a study, the aerosols formed from contaminated the hot tap water with Legionella pneumophila were evaluated.

CONCLUSIONS

there is evidence of aerosol formation during cleanup activities in CSD. Studies on occupational diseases of respiratory origin of workers who work in CSD should be performed.

Surgical clothing systems in laminar airflow operating room: a numerical assessment

This study compared two different laminar airflow distribution strategies - horizontal and vertical - and investigated the effectiveness of both ventilation systems in terms of reducing the sedimentation and distribution of bacteria-carrying particles. Three different staff clothing systems, which resulted in source strengths of 1.5, 4 and 5 CFU/s per person, were considered. The exploration was conducted numerically using a computational fluid dynamics technique. Active and passive air sampling methods were simulated in addition to recovery tests, and the results were compared. Model validation was performed through comparisons with measurement data from the published literature. The recovery test yielded a value of 8.1 min for the horizontal ventilation scenario and 11.9 min for the vertical ventilation system. Fewer particles were captured by the slit sampler and in sedimentation areas with the horizontal ventilation system. The simulated results revealed that under identical conditions in the examined operating room, the horizontal laminar ventilation system performed better than the vertical option. The internal constellation of lamps, the surgical team and objects could have a serious effect on the movement of infectious particles and therefore on postoperative surgical site infections.

Identification and Control of Health Risks in Hospital Environment from the Aspect of Users, Buildings and Systems

Izhodišča: Bolnišnice predstavljajo kompleksno notranje okolje, v katerem so bolniki, zaposleni in obiskovalci izpostavljeni številnim dejavnikom tveganja za zdravje. Raziskav, ki bi obravnavale več dejavnikov tveganja hkrati, je danes malo. Ne izhajajo iz povezave med uporabniki, stavbo in sistemi. Namen metaanalize je prepoznati fizikalne, biološke in kemične dejavnike tveganja za zdravje v bolnišničnem okolju ter izdelati izhodišča za pripravo priporočil za njihovo preprečevanje in obvladovanje. Pri tem bomo upoštevali uporabnike ter življenjski cikel stavbe in sistemov.

Metode: Opravili smo metaanalizo raziskav na področju fizikalnih, bioloških in kemičnih dejavnikov tveganj za zdravje v bolnišničnem okolju. Zajeli smo dve bibliografski bazi (Pub Med in Science Direct). V analizo je bilo vključenih 634 virov literature, ki so bili objavljeni med letoma 1934 in 2012. Izhodišča za pripravo priporočil smo izdelali po nadgrajeni metodi inženirskega načrtovanja.

Rezultati: Na podlagi izsledkov metaanalize smo pripravili izhodišča za pripravo priporočil, ki vključujejo sistematične ukrepe, specifične za bolnišnično okolje. Preprečevanje fizikalnih dejavnikov tveganja za zdravje vključuje ukrepe s področja zakonodaje, načrtovanja stavbe in sistemov ter usposabljanja zaposlenih. Najpomembnejši ukrepi s področja bioloških in kemičnih dejavnikov tveganja za zdravje so: preprečevanje in obvladovanje poti prenosa povzročiteljev bolezni ter nadzor kemičnih onesnaževal v notranjem in zunanjem zraku.

Zaključki: Metaanaliza predstavlja nov pristop k preprečevanju in obvladovanju fizikalnih, bioloških in kemičnih dejavnikov tveganja za zdravje v kompleksnem bolnišničnem okolju - od načrtovanja stavbe do njene uporabe in vzdrževanja. Učinkovitost stavbe in sistemov se doseže s celostnim upoštevanjem značilnosti uporabnikov, bolnišničnega okolja in rabe energije. Uporabljen pristop je tudi pogoj za načrtovanje stavb in sistemov; je temelj uspešnih prenov.

Hospital ventilation simulation for the study of potential exposure to contaminants

Airflow and ventilation are particularly important in healthcare rooms for controlling thermo-hygrometric conditions, providing anaesthetic gas removal, diluting airborne bacterial contamination and minimizing bacteria transfer airborne. An actual hospitalization room was the investigate case study. Transient simulations with computational fluid dynamics (CFD), based on the finite element method (FEM) were performed to investigate the efficiency of the existing heating, ventilation and air-conditioning (HVAC) plant with a variable air volume (VAV) primary air system. Solid modelling of the room, taking into account thermo-physical properties of building materials, architectural features (e.g., window and wall orientation) and furnishing (e.g., beds, tables and lamps) arrangement of the room, inlet turbulence high induction air diffuser, the return air diffusers and two patients lying on two parallel beds was carried out. Multiphysics modelling was used: a thermo-fluidynamic model (convection-conduction and incompressible Navier-Stokes) was combined with a convection-diffusion model. Three 3D models were elaborated considering different conditions/events of the patients (i.e., the first was considered coughing and/or the second breathing). A particle tracing and diffusion model, connected to cough events, was developed to simulate the dispersal of bacteria-carrying droplets in the isolation room equipped with the existing ventilation system. An analysis of the region of droplet fallout and the dilution time of bacteria diffusion of coughed gas in the isolation room was performed. The analysis of transient simulation results concerning particle path and distance, and then particle tracing combined with their concentration, provided evidence of the formation of zones that should be checked by microclimatic and contaminant control. The present study highlights the fact that the CFD-FEM application is useful for understanding the efficiency, adequacy and reliability of the ventilation system, but also provides important suggestions for controlling air quality, patients' comfort and energy consumption in a hospital.