Epidemiology and biostatistics

This section includes a chapter on basic epidemiology and biostatistics as applied to healthcare-associated infections (HAIs). The epidemiology section summarizes various types of studies and outlines the advantages and disadvantages of case–control and cohort studies. It describes the incidence and prevalence rate and how to calculate the most common HAIs. Practical advice is also given on how to avoid bias and confounders. The chapter describes basic concepts in biostatistics and tests of statistical significance used in investigating an outbreak. It also provides guidance on how to calculate the sensitivity and specificity of the test and describes how to interpret confidence intervals and statistical process charts.

Support services

This section discusses the role of hospital support services in the prevention and control of infection. It examines the role and responsibilities of the occupational health department which include pre-employment assessment and provision of guidance on how to manage healthcare workers who are exposed and/or infected with various communicable diseases and multidrug-resistant pathogens. It outlines the importance of infections spread by contaminated environment and provides practical advice on the environmental cleaning. Advice on the management of clinical waste, kitchen and catering services, linen and laundry services, and pest control is also provided.

Control of multidrug-resistant microorganisms

This chapter discusses the burden and impact of antimicrobial resistant (AMR) bacteria on human health. It describes the types of antibiotic resistance, and the various factors which are responsible for promoting the emergence and spread of multidrug-resistant organisms (MDROs) in the healthcare facility. The chapter provides advice on how to successfully implement an antibiotic stewardship programme in hospital and strategies to promote prudent antibiotic prescribing. The role and responsibilities of the antimicrobial management team is also discussed. It provides a summary and characteristic of most commonly encountered MRDOs in a healthcare facility and provide practical advice on how to prevent and control the spread of methicillin-resistant Staph. aureus (MRSA), vancomycin-resistant Enterococcus (VRE), extended-spectrum beta-lactamases (ESBLs), carbapenem-resistant Enterobacteriaceae (CRE), and multidrug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii.

Practical aspects of prevention and control

The chapter examines various types of isolation precautions and provides practical advice on infection prevention and control (IPC) measures to be taken on isolation of patients of new and emerging infectious diseases. In an alphabetical order, it lists IPC precautions, modes of transmission of infections, incubation periods, periods of infectivity, and the duration of isolation for various infectious diseases and multidrug- resistant microorganisms (MDROs). The well-illustrated chapters explain how to properly don and take off various types of personal protective equipment. It reviews the most up-to-date information on the various aspects of hand hygiene, including hand washing and proper use of alcohol-based hand rub products. Practical advice is also given on injection safety, how to prevent transmission of infection after death and prevention of infection by healthcare building design which also includes ventilation of operating theatres.

Building infection prevention programmes

This Chapter examines the global burden of healthcare-associated infections (HAIs) and its impact on healthcare facilities and on individuals. It also provides practical advice on how to successfully build an infection prevention and control (IPC) programme. It also summarizes how to provide low cost and cost-effective IPC services and lists unsafe, ritualistic, and wasteful IPC practices. The chapter examines the responsibilities both of healthcare facilities and healthcare workers in the prevention of HAIs. It also provides guidance on how to organize an IPC programme and discuss the role and responsibility of the infection control doctor and nurse/practitioner and outlines the core competencies required by the IPC team to perform their job effectively. It provides a summary of WHO core components to establish successful IPC programmes both at the national and healthcare facility level. Lists and web links to key IPC professional organizations and regulatory bodies are also provided.

Basic concepts and prevention strategies

This chapter provides a brief description of various microorganisms, and discusses host susceptibility and immune defense mechanisms. It explains how microbes are spread and explains the various modes of transmission of microorganisms in healthcare facilities. It reviews various strategies to prevent and control healthcare-associated infections and discusses the five key elements of the WHO multimodal infection prevention and control (IPC) implementation strategies to prevent, control, and sustain IPC practices in healthcare facilities. The chapter also discusses how to carry out risk assessments in IPC and guide an IPC team on how to set priorities. A brief description is also provided on the root cause analysis.

Disinfection and sterilization

The chapter on decontamination examines various methods of heat sterilization and chemical disinfection. It outlines how to carry out a risk assessment of contaminated items and equipment based on the Spaulding classification and provides practical guidance on how to decontaminate various items in healthcare facilities. It also discusses how to transport items, clean, disinfect, and sterilize various items and equipment in healthcare facility. It outlines various heat sterilization procedures and gives practical advice on how to maintain various types of sterilizer or autoclave and how to safely store sterile items. Detail is also provided on how to use chemical disinfectants in healthcare facilities and summarizes the use and antimicrobial activity of various disinfectants and antiseptics. This chapter also includes advice on decontamination of endoscopes and maintenance of automatic endoscope reprocessors. It also provides practical advice and summarizes the key points on how to investigate and follow up cases after a failure of decontamination process.

Special pathogens

This section includes infection prevention and control (IPC) measures require for bloodborne viral infections, i.e. hepatitis B, hepatitis C, and HIV infection, gastrointestinal infections, i.e. Clostridium difficile associated diarrhoea, norovirus, and rotavirus, microorganisms spread via respiratory route, e.g. tuberculosis, influenza, respiratory syncytial virus (RSV), coronavirus (SARS and MERS-CoV), and Legionnaires’ disease. Separate parts deal with other common infections, e.g. varicella zoster virus (VZV), meningococcal infections, viral haemorrhagic fevers e.g. Lassa, Ebola, Marburg and Crimean-Congo haemorrhagic fever and human prion diseases, e.g. Creutzfeldt–Jakob disease (CJD). It also includes IPC advice on the management of scabies and infestation with lice and fleas.

Prevention of healthcare associated infections

This chapter provides the most up-to-date advice on infection prevention and control (IPC) of the four most common healthcare-associated infections (HAIs). These are: surgical site infections; infection associated with peripheral IV line/cannula and central line-associated bloodstream infections (CLABSIs); catheter-associated urinary tract infections (CAUTI); and hospital-acquired and ventilator-acquired pneumonias (VAP). The chapter examines and summarizes various key elements and discusses implementation of HAI care bundles and high impact interventions which are necessary to reduce these infections.

Surveillance and outbreak management

This chapter describes the surveillance of healthcare-associated infections (HAIs) and outlines the management of an outbreak. The chapter on surveillance describes the objectives and advantages and disadvantages of various surveillance strategies. It describes how to collect and validate surveillance data and calculate various HAI rates. It also summarizes the advantages and disadvantages of both outcome and process surveillance. It provides a list of alert infectious conditions and alert organisms which need to be monitored by healthcare facilities. Advice is also given on how to recognize and manage an outbreak, and the role of the microbiology laboratory. It provides advice on how to develop an epidemic curve and summarizes what steps should be taken on an investigation of an outbreak.