Use of Biocidal Surfaces for Reduction of Healthcare Acquired Infections

The notion that contaminated environments in hospital settings significantly contribute to the risk of an individual acquiring an infection while hospitalized is continuously gaining recognition by the medical community. There is a clear correlation between the environmental bioburden present in a clinical setting and the risk of patients acquiring an infection. Thus using self-disinfecting surfaces can be a very important adjunct in the fight against nosocomial pathogens. This book reviews the increasing evidence that contaminated non-intrusive soft and hard surfaces located in the clinical surroundings are a source of nosocomial pathogens and focuses on the utility of copper containing materials in reducing bioburden and fighting hospital acquired infections. It also reviews other biocidal surface alternatives and the economics of using biocidal surfaces in a hospital environment. Finally, it discusses the pros and cons of existent disinfection modalities other than biocidal surfaces. Contents 6 Chapter 1: Preface 7 References 10 Chapter 2: Survival of Microorganisms on Inanimate Surfaces 13 2.1 Introduction 14 2.2 The Role of Surfaces in the Transmission of Pathogenic Microorganisms Causing Healthcare-Acquired Infections (HAI) 15 2.3 Persistence of Microorganisms on Inanimate Surfaces 16 2.3.1 Persistence of Bacteria 17 2.3.2 Persistence of Viruses 17 2.3.3 Persistence of Fungi 19 2.3.4 Persistence of Other Pathogenic Microorganisms 21 2.3.5 Factors Influencing the Survival of Microorganisms in the Environment 21 2.3.5.1 Relative Humidity (RH) 21 2.3.5.2 Temperature 22 2.3.5.3 Biofilm 22 2.3.5.4 Other Factors 23 2.3.6 Limitations on the Knowledge of Microbial Survival on Inanimate Surfaces 23 2.4 Mechanisms of Transmission from Inanimate Surfaces to Susceptible Patients and Consequences Thereof 24 References 25 Chapter 3: The Role of Contaminated Surfaces in the Transmission of Nosocomial Pathogens 33 3.1 Introduction 35 3.2 Pathogens Are Shed into the Hospital Environment 36 3.3 The Concentration of Contamination Is Sufficient for Transmission 37 3.4 Nosocomial Pathogens Can Survive on Surfaces for Long Periods 38 3.5 Limitations of Cleaning and Disinfection 39 3.6 Nosocomial Pathogens Can Be Transferred from Contaminated Surfaces to the Hands of Healthcare Workers 40 3.7 Evidence That Surface Contamination Contributes to Nosocomial Cross-Transmission 42 3.7.1 Clostridium Difficile 44 3.7.2 Vancomycin-Resistant Enterococci (VRE) 46 3.7.3 MRSA 47 3.7.4 Gram-Negative Rods (GNRs) 47 3.7.4.1 Non-fermenting Gram-negative bacteria (Acinetobacter and Pseudomonas) 47 3.7.4.2 Enterobacteriaceae 48 3.7.5 Norovirus 49 3.7.6 Revaluating ``Negative ́ ́ Studies 50 3.8 Environmental Cleaning, Disinfection and Infection Control 51 3.8.1 Improving the Efficacy of Cleaning and Disinfection 51 3.8.2 Evaluating and Implementing New Technology 52 3.8.3 Reducing and Controlling the Extent of Environmental Contamination 53 3.8.4 Antimicrobial Surfaces 54 3.8.5 Improving the Quality of the Evidence 55 3.9 Conclusion 55 References 56 Chapter 4: Role of the Microbial Burden in the Acquisition and Control of Healthcare Associated Infections: The Utility of Sol... 65 4.1 Introduction 67 4.2 Role of the Environment in Healthcare Infection 68 4.2.1 Microbes in the Built Environment 68 4.2.2 Transmission of Pathogens to Patients and Healthcare Workers 70 4.2.3 Contamination of Medical Equipment 72 4.2.4 Risk to Patient When Prior Room Occupant Colonized or Infected with Epidemiologically Important Organisms 72 4.3 No-Touch Disinfection Technologies 75 4.4 Antimicrobial Copper: A Continuously Active No-Touch Disinfection Solution for Healthcare 77 4.5 Postulated Mechanism of Action of Solid Metallic Cooper 81 4.6 Use of Copper Surfaces in Healthcare 81 4.7 Summary 83 References 83 Chapter 5: Biocidal Hard and Soft Surfaces Containing Copper Oxide Particles for the Reduction of Healthcare-Acquired Pathogens 90 5.1 Hospital Textiles as a Source of Healthcare-Acquired Pathogens 91 5.2 Biocidal Textiles as a Tool to Fight Healthcare-Acquired Infections 93 5.3 Biocidal Textiles Containing Copper Oxide 95 5.4 Non-porous Solid Biocidal Surfaces Containing Copper Oxide 98 References 100 Chapter 6: Biocidal Mechanisms of Metallic Copper Surfaces 107 6.1 The Biocidal History of Copper 109 6.2 Copper the ``Modern ́ ́ Bioelement 111 6.2.1 General Chemistry Properties 111 6.2.2 How Organisms Use Copper 111 6.2.3 Copper Homeostasis 112 6.2.4 Ionic Copper Toxicity 114 6.3 Metallic Copper Surfaces as a Biocidal Tool 116 6.3.1 Quick Cell Inactivation by Metallic Copper Surfaces 116 6.3.1.1 Copper Surface Oxidation and Cell Accumulation 119 Copper Release and Accumulation Under Wet Conditions 119 Copper Release and Accumulation Under Dry Conditions 119 Survival Depends on Buffer Composition and Surface Corrosion 120 6.3.2 Additional Physical and Physiological Factors Modulating the Contact-Killing Process 122 6.3.2.1 Copper Alloy Content and Roughness 122 6.3.2.2 Temperature and Moisture 122 6.3.2.3 Copper Chelators 123 6.3.2.4 Osmotic Stress 124 6.3.2.5 Reactive Oxygen Species 124 6.3.2.6 Cellular Physiology 124 Cell Wall Structure 124 Spores 125 Copper Detoxifying Systems and Pre-adaptation to Copper 125 Anaerobiosis 125 Viable-But-Not-Culturable (VBNC) 127 6.3.3 Cellular Targets of Metallic Copper Toxicity 127 6.3.3.1 DNA Mutations and Degradation 127 6.3.3.2 Membrane Permeability 128 6.3.3.3 Lipid Oxidation Chemistry 130 6.4 Holistic ``Systems View ́ ́ of Biocidal Effect of Metallic Copper 133 6.5 Metallic Copper Under Healthcare Environments 134 6.6 Closing Remarks 135 References 136 Chapter 7: An Overview of the Options for Antimicrobial Hard Surfaces in Hospitals 141 7.1 Role of the Environment in Transmission 143 7.1.1 Evidence That Contaminated Surfaces Contribute to Transmission 143 7.1.2 The Relationship Between Contamination Burden and Transmission Risk 143 7.1.3 Potential Role for Antimicrobial Surfaces 146 7.2 Current Options and the `Ideal ́ Candidate for Antimicrobial Surfaces 147 7.2.1 Considering the `Ideal ́ Antimicrobial Surface 150 7.3 Assessing Antimicrobial Surfaces 151 7.3.1 In Vitro Activity 151 7.3.2 In Situ Activity 152 7.3.3 Clinical Impact 158 7.3.4 Cost-Effectiveness 158 7.4 Appraising the Options 159 7.4.1 Metals 159 7.4.1.1 Copper 159 7.4.1.2 Silver 161 7.4.2 Chemical 162 7.4.2.1 Organosilane 162 7.4.2.2 Quaternary Ammonium Compound 162 7.4.2.3 Light-Activated 162 7.4.2.4 Polycationic Polymers 163 7.4.2.5 Triclosan 163 7.4.3 Physical Alteration of Surface Properties 164 7.4.4 Other Options 164 7.5 Summary 164 References 164 Chapter 8: Economics of Using Biocidal Surfaces 171 8.1 Introduction 172 8.2 Evaluation of ICU Cost Effectiveness 173 8.3 Antimicrobial Copper Cu+ Implementation in NICU (Neonatal Intensive Care Unit) 176 8.4 Economic Impacts on the Operational Costs of the ICU After Antimicrobial Copper Cu+ Implementation 179 8.4.1 APACHE II Score 183 8.4.2 SAPSII Score 184 8.5 Analytically 187 8.6 Conclusions 188 References 189 Chapter 9: Alternative Room Disinfection Modalities - Pros and Cons 191 9.1 Introduction 192 9.2 Methods 196 9.3 Results 196 9.3.1 Fumigation Benefits: Efficacy, Effectiveness and Efficiency 196 9.3.2 Fumigation Risks: Health and Safety and Costs 199 9.3.3 UVC Germicidal Irradiation Risks and Benefits 199 9.4 Discussion 202 9.5 Conclusion 206 References 206 Index 212 Front Matter....Pages i-v Preface....Pages 1-6 Survival of Microorganisms on Inanimate Surfaces....Pages 7-26 The Role of Contaminated Surfaces in the Transmission of Nosocomial Pathogens....Pages 27-58 Role of the Microbial Burden in the Acquisition and Control of Healthcare Associated Infections: The Utility of Solid Copper Surfaces....Pages 59-83 Biocidal Hard and Soft Surfaces Containing Copper Oxide Particles for the Reduction of Healthcare-Acquired Pathogens....Pages 85-101 Biocidal Mechanisms of Metallic Copper Surfaces....Pages 103-136 An Overview of the Options for Antimicrobial Hard Surfaces in Hospitals....Pages 137-166 Economics of Using Biocidal Surfaces....Pages 167-186 Alternative Room Disinfection Modalities – Pros and Cons....Pages 187-207 Back Matter....Pages 209-215