Glossary of terms

Aerobe: An organism that grows in the presence of oxygen.

Aerobic Colony Count: The number/type of pathogens recovered from a surface.

Anaerobe: An organism that grows in the absence of oxygen.

Alcohol Hand Rub (AHR): A formulation of alcohol (e.g. ethanol, isopropanol, n-propanol) used to reduce the number of microorganisms on hands that are not visibly soiled.

Antibiotic-Resistant Organism (ARO): A microorganism that has developed resistance to the action of certain classes of antibiotics.

Antiseptic: An agent that can kill or inhibit microorganisms on living tissue and skin.

Bactericidal: Lethal activity against bacteria.

Bioburden: The numbers and types of microorganisms on a contaminated surface.

Biocide: Usually a broad-spectrum chemical or physical agent that inactivates microorganisms.

Cleaning: The physical removal of foreign material (e.g. dust, soil) and organic material (e.g. blood, secretions, excretions, microorganisms) with water, detergents and mechanical action.

Contamination: The presence of an infectious agent on hands and fomites.

Contact Time: The time necessary for a disinfectant to results in a significant reduction (usually 3 log reduction) in microorganisms.

Detergent: An emulsifying agent that contains surfactants and/or protease enzymes and whitening agents.

Disinfectant: A chemical applied on surfaces or medical equipment/devices which is capable of disinfection.

Disinfection: The process of removing/reducing the numbers of an infectious agent. Disinfection does not destroy bacterial spores.

Fomites: An inanimate object that may be contaminated with microorganisms and serve as a vehicle of transmission.

Healthcare-Associated Infection (HCAI): A term relating to an infection that is acquired during the delivery of healthcare (also known as nosocomial infection).

High-Touch Surfaces: High-touch surfaces are those that have frequent contact with hands. Examples include doorknobs, call bells, bedrails, light switches, wall areas around the toilet and edges of privacy curtains.

Infection: The entry and multiplication of an infectious agent in the tissues of the host Infection Prevention and Control: Evidence-based practices and procedures that, when applied consistently in healthcare settings, can prevent or reduce the risk of infection in clients/patients/residents, healthcare providers and visitors.

Low-Level Disinfection (LLD): Level of disinfection required when processing non-invasive medical equipment (i.e., non-critical equipment) and some environmental surfaces. Equipment and surfaces must be thoroughly cleaned prior to low-level disinfection.

Low-Touch Surfaces: Surfaces that have minimal contact with hands. Examples include walls, ceilings, mirrors and window sills.

Microbicide: A substance that destroys infectious agents, including, bacteria, viruses and fungi.

Neutralisation: The ability to stop the activity of a microbicide at a defined exposure time.

Reservoir: Any person, animal, substance or environmental surface in or on which an infectious agent survives or multiplies, posing a risk for infection.

Sporicidal: Lethal activity against spores Sporistatic: Inhibition of spore germination.


ACC – Aerobic colony count.

AHR – Alcohol Hand Rub.

ATP – Adenosine Triphosphate.

CDC – Centres for Disease Control and Prevention.

CDI – Clostridium difficile Infection.

HCAI – Healthcare-Associated Infections.

HCW – Healthcare Workers.

KPC – Klebsiella pneumonia carbapenemase.

LLD – Low-Level Disinfection.

MRSA – Methicillin-Resistant Staphylococcus aureus.

MSDS – Material Safety Data Sheet.

NAO – National Audit Office.

PPM – Parts Per Million.

QAC – Quaternary Ammonium Compound.

RCN – Royal College of Nursing.

UVI – Ultraviolet Irradiation.

VHP – Vapourised Hydrogen Peroxide.

VOC – Volatile Organic Compounds.

VRE – Vancomycin-Resistant Enterococci.