For the purpose of discussion, many general terms are used throughout the book. These include words such as “cleaning”, “disinfection”, “sterilization”, “ decontamination”, etc. These are specifically defined here. They can have very specific meanings and are often misused. These definitions can vary from country to country or depending on their particular use in certain applications. In many cases there is currently no universal acceptance of some definitions, but wherever possible internationally accepted definitions have been used. Further definitions related to specific discussions in the book, for example in the chapters on anatomy, physiology and biochemistry (Chapter 2), microbiology and infection control/prevention (Chapter 5), and chemistry (Chapter 6) are provided in these respective chapters.
Anatomy The study of the structure of living things. Anion Negatively charged atom or molecule, with examples being Cl− (the chloride ion) and OH− (the hydroxide ion). Antibiotics Drugs that kill or inhibit the growth of bacteria and some fungi by interfering with their normal functions. They are used to prevent (“prophylactic”) or treat bacterial and some fungal infections.
Anti-infectives Drugs that can kill or inhibit the growth of infectious agents. These drugs are usually specific in the way they work; they are therefore classified as antibacterials, antifungals, antivirals and antiprotozoal agents.
Antimicrobial The ability of a process or product to be effective against microorganisms by either killing them or inhibiting their growth. Antimicrobials include drugs that are particularly used therapeutically within patients to control infections. These are often referred to as anti-infectives or “drugs” and include antibiotics, antifungals and antiviral agents. These are generally specific in their activity, being active against a very limited range of microorganisms. For example, antibiotics only work against some kinds of bacteria (and sometimes some fungi) and most antiviral agents only target certain classes of viruses. These are not discussed in any detail in this book. The antimicrobial chemicals that are used in disinfection and sterilization applications are often referred to as “biocides” or “microbiocides”.