Master of Science / Department of Architectural Engineering and Construction Science / Julia A. Keen / Health care facilities are responsible for treating highly infected and contagious patients at the same time as patients who are most susceptible to disease. Therefore, it is important that every available technology and application to be strategically applied to protect each and every occupant. In particular, ultraviolet germicidal irradiation (UVGI) technologies are being used in today's industry as infection control devices, primarily in health care facilities. This paper addresses the effectiveness and economic impact of applying UVGI to remove harmful airborne pathogens and outlines background information on infectious airborne pathogens such as viruses, bacteria, and fungi. Besides UVGI, other engineering control methods covered in this paper include mechanical ventilation and air distribution, filtration, and differential pressure control. Consequently, an economic evaluation of a diagnostic and treatment area was created to compare UVGI technologies and other control methods. The evaluation consists of a baseline system designed to meet code requirements; an upper-room UVGI system; a heating, ventilating, and air-conditioning (HVAC) system with an increased air changes per hour (ACH); and a UVGI system in an AHU. First costs, energy costs, and maintenance costs were the basis of economic comparison. The predicted effectiveness of all the alternatives was held constant and the time required to achieve the desired effectiveness was determined. As a result, the upper-room UVGI system and HVAC system with an increased ACH yielded much higher comparative annual costs as well as significantly better room disinfection effectiveness. The UVGI system in the AHU resulted in a lower comparative annual cost than the baseline system with the same room disinfection effectiveness. By designing infection control systems with UVGI, HVAC engineers will be more capable and successful in providing the optimal control system to these critical facilities.

M.Cur / According to data from the Centers for Disease Control and Prevention’s(CDC) National Nosocomial Infections Surveillance System of 1996, Pseudomonas aeruginosa(P. aeruginosa) can be rated as the number two cause of nosocomial pneumonia(Chen & Rudoy,2006). Nosocomial pneumonia increases hospital cost and morbidity and mortality in patients. Most of the patients in the critical care unit are immune compromised because of underlying illnesses. Antibiotics eliminates the patient’s normal flora which causes opportunity for pathogens to colonise. Indwelling procedures like endotracheal intubation cause a point of entrance for pathogens like P.aeruginosa. The endotracheal tube bypasses the normal physiological processes and inhibits the cough reflex. It is the nurse’s responsibility to remove secretion through endotracheal suctioning. During the past ten years the closed suction method was increasingly implemented to remove secretions because studies showed closed suction caused less infection than open suction. In a spesific critical care unit in a private hospital in Pretoria the nurses are of the opinion that closed suctioning does not effectively remove secretion. Patients are therefore suctioned open which can cause air contamination because the colonised ventilator circuit is opened. The following question can be asked in view of the above arguments and problem statement: Is there a difference in aircontamintion between open and closed suctioning? The aim of the study is to determine whether any difference in air contamination exists between open and closed suctioning in a spesific critical care unit in Pretoria. v A comparitive contextual design with crossover methods was used. Patients are allocated to group 1 or group 2 through random sampling. An air exstractor is used to take airsamples before, during and after suctioning. There was no significant difference in terms of air contamination for open and closed suction. This is probably because of too small a sample. The null hypothesis is accepted and that is there is no significant difference in air contamination between open and closed suction.

ESKAPE pathogens are notorious in causing nosocomial infections and escaping current antibiotic treatments. There has been a dramatic increase in nosocomial infections accompanied with a decrease in the number of antibiotics developed, leading to significant increase in morbidity and mortality among patients. In an attempt to combat this problem, derivatives of ciprofloxacin, rifabutin and beta-lactam antibiotics were synthesized and tested against the ESKAPE pathogens. From minimum inhibitory concentration assays, 4 ciprofloxacin analogs and 8 beta-lactam analogs were found to be effective against multiple bacterial species. Additionally, 12 rifabutin analogs and 23 beta-lactam analogs were potent against single bacterial species, primarily toward methicillin-resistant Staphylococcus aureus (MRSA) at a concentration of ≤ 25 µg mL-1. Based on the effectiveness against methicillin-resistant Staphylococcus aureus (MRSA), three rifabutin analogs were selected for further testing. Two rifabutin analogs (DU644 and DU645) were found to possess between a one to twofold mean increase of inhibitory activities, while the other rifabutin analogs (DU650) demonstrated up to a twofold decrease of inhibitory activity when compared to the parent drug. These compounds were then examined for their bactericidal and antibiofilm activities against MRSA. From these assays, we found that DU644 and DU645 were 4 times more bactericidal and antibiofilm against MRSA when compared to the parent drug. In addition, rpoB mutation validation results confirmed that modification of these rifabutin derivatives at the C3 and C4 positions, and bearing an imidazolyl ring carrying substituted spiropiperidyl ring, did not change their mechanism of action towards the beta-subunit of RNA polymerase. Cytotoxicity testing performed using human hepatocellular carcinoma epithelial cells (hepG2) showed that at concentrations ranged from 1.25 µg mL-1 to 25 µg mL-1, DU644 and DU645 showed very low toxicity. Collectively, structural drugs modifications of these obsolete drugs are able to restore their antibacterial activities against MRSA, which is notable as the most infectious nosocomial pathogen. Therefore, further development and application of rifabutin analogs might be beneficial for medical use to combat MRSA infections.

No description available.

Preventing healthcare-associated infections (HAI) is a national priority. The Centers for Disease Control and Prevention estimates that one of every 25 hospitalized patients contract a HAI while receiving care. In 2009, the annual cost for HAIs in United States’ hospitals was estimated to be $40 billion, and there were 99,000 HAI-associated deaths. In nursing homes (NH), the situation is more dire; among the 4 million NH residents each year, there are 1-2.6 million serious infections and 1 out of every 3 NH residents is colonized with a multi-drug resistant organism. In addition to the frequent infections, over prescription of antibiotics in NH is significant, and frequently inappropriate. NH residents with HAIs are subjected to burdensome treatments and diagnostic procedures, leading to more complications in an already vulnerable population in which quality of life not life prolongation is often the treatment goal. Policy levers are actions designed to realize health objectives that can be taken by either public or private entities, and by individuals or groups. Health policy levers are deployed at all levels including federal, state, regional, and local levels. Vaccinations, such as polio, are one of the great success stories of how policy levers can prevent infections. However, undermined and eroded policy levers can have negative public health consequences, such as seen with the 2018-2019 rash of measles outbreaks. There is much work left to be done improving quality related to infections across all care settings. For this dissertation, I utilized the three-paper format and conducted studies examining the effectiveness of health policy levers used to improve healthcare quality and prevent infections across care settings. These studies were: 1) a systematic review of the published evidence on state mandatory reporting of HAI in hospitals; 2) an environmental scan cataloging state supported initiatives in NH infection prevention, and; 3) a quantitative analysis on the effect of new federal NH regulations on NH quality and patient outcomes. In the systematic review, I found that mandatory reporting was associated with reduced central line associate bloodstream infection rates. The environmental scan demonstrated that wide variation existed between states’ initiatives to support infection prevention in NH. In the quantitative analysis, I found that new federal regulations were significantly associated in improved NH quality in UTI rates and vaccination rates for influenza and pneumonia infections. Based on these results, clinical providers, administrators, policy makers and researchers can use health policy levers to reduce infections and improve quality.

Nosokomiale Infektionen (NKI) gehören zu den häufigsten Komplikationen eines Krankenhausaufenthaltes, insbesondere auf Intensivstationen mit einer Prävalenz von rund 18,65%. Die Folgen sind eine längere Verweildauer, erhöhte Morbidität und Letalität sowie höhere Kosten für das Gesundheitssystem. Die Erfassung NKI stellt einen wichtigen Qualitäts- Parameter für Intensivstationen dar. Ziel dieser Arbeit war es, die Übereinstimmung von nur nach KISS (Krankenhaus-InfektionsSurveillance System)- Definitionen erfassten Infektionen mit der klinisch diagnostizierten nosokomialen Infektion zu prüfen und den Zusammenhang zwischen ärztlicher Diagnose und den laborchemischen und klinisch erhobenen Kriterien darzustellen. Hierfür wurden auf einer interdisziplinären operativen Intensivstation nosokomiale Infektionen sowohl nach ITS- KISS (VAP, ZVK- assoziierte Infektionen und HWI), als auch nach ärztlicher Diagnose plus Beginn oder Eskalation einer Antibiotikatherapie erfasst. Zusätzlich zu den KISS-Parametern wurden laborchemische Entzündungsparameter (CRP und PCT) registriert. Es traten 32 Infektionen nach ITS- KISS und 69 Infektionen nach ärztlicher Diagnose auf. Acht Infektionen wurden ausschließlich nach KISS und 45 ausschließlich nach der ärztlichen Diagnose erfasst. Die Infektionsrate nach KISS für VAP lag bei 20,6, für ZVK bei 5,9 und für HWI bei 2 Infektionen, jeweils pro 1000 Devicetage. Spezifität und positiv prädiktiver Wert hinsichtlich der Vorhersage einer ärztlich diagnostizierten Infektion waren gering. Auch durch Kombination verschiedener Parameter wurden keine höheren prädiktiven Werte erreicht. Die geringe Übereinstimmung der beiden Methoden legt nahe, dass KISS die klinisch relevanten Infektionen nicht wesentlich erfasst und relevante Infektfoci nicht berücksichtigt werden, beispielsweise abdominelle Infektionen. Zudem erlauben die erfassten Laborparameter keine zuverlässige Diagnose bzw. Prädiktion einer nosokomialen Infektion. Die ärztliche Diagnose in Verbindung mit dem Beginn oder der Eskalation einer Antibiotikatherapie könnte eine vereinfachte Methode zur Surveillance nosokomialer Infektionen darstellen.

Healthcare-associated infections (HAIs) are among the most common and significant patient safety issues posing great threats to public health. One in every 25 inpatients in the United States experiences a HAI. Because they have continuously been a major reason for increased morbidity and mortality in healthcare facilities, increased attention to understanding the spread of HAIs is an urgently needed. Therefore, the purpose of this dissertation, was to examine the risk factors for two of the most common HAIs (surgical site infection [SSI] and Clostridioides difficile infection [CDI]), using multiple methodological approaches. Chapter 1 provides an overview of HAIs, the risk factors identified from the previous literature, and the necessity of different methodological approaches to identify the risk of HAIs. Chapter 2 is an integrative review synthesizing the findings from seven published studies examining the association between the development of pocket hematoma and the risk of wound infection in individuals with cardiovascular implantable electronic devices. Chapter 3 is a summary of a retrospective cohort study using machine learning techniques—logistic regression, decision tree, and support vector machine approaches—to build predictive models of SSI among individuals with permanent pacemakers, followed by a comparison of the predictive abilities of the three algorithms. Chapter 4 describes a retrospective matched case-control study to examine (1) temporal changes in the incidence of community or hospital-acquired CDI, (2) the risk factors for hospital-acquired CDI including individual-host factors and pharmacological-related factors, and (3) temporal changes in the risk factors for hospital-acquired CDI. Lastly, Chapter 5 summarizes and synthesizes the findings of the studies included in this dissertation, the strengths and limitations of the studies, implications for public health and clinical practice, advanced studies on methodology, and future research. In conclusion, this dissertation adds comprehensive knowledge regarding the associations between risk factors and HAIs by identifying reliable risk factors measured in various ways and applying various methodological approaches.

No description available.

Health care-associated and hospital-acquired infections are two entities associated with increased morbidity and mortality. They are highly costly and constitute a great burden to the health care system. Vitamin D deficiency (< 20 ng/ml) is prevalent and may be a key contributor to both acute and chronic ill health. Vitamin D deficiency is associated with decreased innate immunity and increased risk for infections. Vitamin D can positively influence a wide variety of microbial infections. Herein we discuss hospital-acquired infections, such as pneumonia, bacteremias, urinary tract and surgical site infections, and the potential role vitamin D may play in ameliorating them. We also discuss how vitamin D might positively influence these infections and help contain health care costs. Pending further studies, we think it is prudent to check vitamin D status at hospital admission and to take immediate steps to address existing insufficient 25-hydroxyvitamin D levels.

Accurate assessment of disease dynamics requires a quantification of many unknown parameters governing disease transmission processes. While infection control strategies within hospital settings are stringent, some disease will be propagated due to human interactions (patient-to-patient or patient-to- caregiver-topatient). In order to understand infectious transmission rates within the hospital, it is necessary to isolate the amount of disease that is endemic to the outside environment. While discerning the origins of disease is difficult when using ordinary spatio-temporal data (locations and time of disease detection), genotypes that are common to pathogens, with common sources, aid in distinguishing nosocomial infections from independent arrivals of the disease. The purpose of this study was to demonstrate a Bayesian modeling procedure for identifying nosocomial infections, and quantify the rate of these transmissions. We will demonstrate our method using a 10-year history of Morexella catarhallis. Results will show the degree to which pathogen-specific, genotypic information impacts inferences about the nosocomial rate of infection.