NHS England » Glossary of terms

Oct 31, 2023

A graze. A minor wound in which the surface of the skin or a mucous membrane has been worn away by rubbing or scraping.

A medical procedure that can result in the release of aerosols from the respiratory tract. The criteria for an AGP are a high risk of aerosol generation and increased risk of transmission (from patients with a known or suspected respiratory infection).

Very small particles (of respirable size) that may contain infectious agents. They can remain in the air for extended periods of time and can be carried over long distances by air currents. Aerosols can be released during aerosol generating procedures (AGPs).

A group of transmission based precautions to prevent the spread of airborne pathogens.

The spread of infection from one individual to another by airborne particles (aerosols) containing infectious agents. Airborne particles are very small particles that may contain infectious agents. They can remain in the air for long periods of time and can be carried over long distances by air currents.

Airborne particles can be released when an individual coughs or sneezes, and during AGPs. ‘Droplet nuclei’ are aerosols formed from the evaporation of larger droplet particles (see droplet transmission). Aerosols formed from droplet particles in this way behave as other aerosols. Airborne precautions are measures used to prevent, and control infection spread without necessarily having close patient contact via aerosols from the respiratory tract of one individual directly onto a mucosal surface or conjunctivae of another individual. Aerosols can penetrate the respiratory system to the alveolar level.

A gel, foam or liquid containing one or more types of alcohol that is rubbed into the hands to inactivate microorganisms and/or temporarily suppress their growth.

An organism that is identified as being potentially significant for infection prevention and control practices. Examples of alert organisms include meticillin resistant staphylococcus aureus (MRSA), Clostridioides difficile (C.diff) and Group A Streptococcus.

Refers to the alveoli which are the small air sacs in the lungs. Alveoli are located at the ends of the air passageways in the lungs and are the site at which gas exchange takes place.

An area with a door from/to the outside corridor and a second door giving access to the patient area (where both doors will never be open at the same time).

[See ‘ventilated lobby’.]

An agent that kills microorganisms or prevents their growth. Antibiotics and disinfectants are antimicrobial agents.

The ability of a microorganism to resist the action of an antimicrobial drug/agent which was previously effective in treating the infection caused by that microorganism.

[See ‘multi-drug resistant organism’.]

The process of preventing infection by inhibiting the growth and multiplication of infectious agents. This is usually achieved by application of a germicidal preparation known as an antiseptic.

A procedure or task that requires an aseptic technique such as inserting invasive devices like vascular or urinary catheters, performing surgery or changing dressings.

Refers to a practice/procedure designed to minimise the risk of contamination from microorganisms into a wound, on insertion or ongoing care of a medical device such as a vascular access device or urethral catheter or during surgical procedures.

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Viruses carried or transmitted by blood, for example Hepatitis B, Hepatitis C and HIV.

Fluid produced by the body such as urine, faeces, vomit or diarrhoea.

Mandatory technical specifications created by either the British Standards Institute (BS) or European Standardisation Organisations (EN) in collaboration with government bodies, industry experts and trade associations. They aim to ensure the quality and safety of products, services, and systems. Table 1 provides an example of the EN standards relevant to disinfectant used in the management of blood and body fluid spills.

Table 1: standards relevant to disinfectants used in the management of blood and body fluid spills.

A phase 2 step 1 suspension test for disinfectants intended for use in the food, industrial, domestic, and institutional areas. The test evaluates the efficacy of the product against bacterial and fungal spores.

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A group of bacteria that have become extremely resistant to the carbapenem class of antibiotics.

Includes but is not limited to general practice, dental and pharmacy (primary care), acute-care hospitals, emergency medical services, mental health, urgent-care centres and outpatient clinics (secondary care), specialist treatment centres (tertiary care), long-term care facilities such as nursing homes and skilled nursing facilities (community care), and care provided at home by professional healthcare providers (home care).

Any person who cares for patients, including healthcare support workers and nurses.

A large, centralised facility for the decontamination and re-processing of re-usable medical equipment eg surgical instruments.

An intravenous catheter that is inserted directly into a large vein in the neck, chest or groin to allow intravenous drugs and fluids to be given and to allow blood monitoring.

A chemical element commonly present in compounds used for disinfecting the care environment. It may be referred to as the concentration of ‘available chlorine (av. cl.) in parts per million (ppm) of a product.

A process that physically removes contamination such as dirt, body fluids (blood, vomit), etc by use of an appropriate cleaning agent such as detergent. Cleaning also removes some microorganisms and, if soiling is present, is an essential step before effective disinfection or sterilisation can be performed.

An infectious agent (bacterium) that can cause mild to severe diarrhoea which in some cases can lead to gastro-intestinal complications and death.

A sink designated exclusively for hand washing in clinical areas by care staff.

An area (room, bay, ward) in which two or more patients (a cohort) with the same confirmed infection are placed. A cohort area should be physically separate from other patients.

The presence of microorganisms on a body surface (such as the skin, mouth, intestines or airway) that does not cause disease in the person or signs of infection.

Mucous membranes that cover the front of the eyes and the inside of the eyelids.

Measures used to prevent and control infections that spread via direct contact with the patient or indirectly from the patient's immediate care environment (including care equipment).

Contact transmission consists of two distinct types: direct contact and indirect contact. Direct transmission occurs when microorganisms are transmitted directly from an infectious individual to another individual without the involvement of another contaminated individual or object (fomite). Indirect transmission occurs when micro-organisms are transmitted from an infectious individual to another individual through a contaminated object (fomite) or person.

The spread of infectious agents from one person to another by contact. When spread occurs through skin-to-skin contact, this is called direct contact transmission. When spread occurs via a contaminated object, this is called indirect contact transmission.

The presence of an infectious agent on a body surface; also, on or in clothes, bedding, surgical instruments or dressings, or other inanimate articles or substances including water and food.

Measures that are taken to minimise the spread of respiratory infections to others.

Spread of infection from one individual, object or place to another.

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A process, or combination of processes that removes or destroys contamination on an item or surface to make it safe for handling, re-use or disposal, by preventing infectious agents or other contaminants reaching a susceptible site in sufficient quantities to initiate infection, or other harmful response. Decontamination may include cleaning, disinfection and/or sterilisation.

A chemical cleansing agent that can dissolve oils and remove dirt.

Three or more loose or liquid bowel movements in 24 hours or more often than is normal for the individual.

Spread of infectious agents from one individual to another by direct skin-to-skin contact.

A chemical used to reduce the number of infectious agents from an object or surface to a level that means they are not harmful to health.

The treatment of surfaces/equipment using physical or chemical means, for example, using a chemical disinfectant, to reduce the number of microorganisms present on an object or surface to a level that is unlikely to cause infection. Successful disinfection is dependent on the number of microorganisms initially present. Therefore, physical cleaning is a prerequisite to effective disinfection.

Waste produced in the care setting that is similar to waste produced in the home.

Measures used to prevent, and control infections spread over short distances (at least 1 metre) via droplets from the respiratory tract of one individual directly onto a mucosal surface or conjunctivae of another individual. Droplets penetrate the respiratory system to above the alveolar level.

The spread of infection from one individual to another by droplets containing infectious agents.

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An agent used to soothe the skin and make it soft and supple.

A room containing a sink and toilet and sometimes a shower/wetroom or bath.

Waste products produced by the body such as urine and faeces (bowel movements).

The condition of being exposed to something that may have a harmful effect such as an infectious agent.

Certain medical and patient care procedures where there is a risk that injury to the healthcare worker may result in exposure of the patient's open tissues to the healthcare worker's blood eg the healthcare worker's gloved hands are in contact with sharp instruments, needle tips or sharp tissues inside a patient's body.

Worn when there is a risk from splashing of secretion (including respiratory secretions). Eye or face protection can be achieved using any one of:

A disposable FRSM worn over the nose and mouth to protect the mucous membranes of the wearer's nose and mouth from splashes and infectious droplets. FRSMs can also be used to protect patients. When recommended for infection control purposes a ‘surgical face mask’ typically denotes a fluid-resistant (Type IIR) surgical mask.

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Respiratory protection that is worn over the nose and mouth designed to protect the wearer from inhaling hazardous substances, including airborne particles (aerosols). FFP stands for filtering facepiece. There are three categories of FFP respirator: FFP1, FFP2 and FFP3. An FFP3 respirator or hood provides the highest level of protection and is the only category of respirator legislated for use in UK healthcare settings.

[See respiratory protective equipment.]

A method of checking that a tight-fitting facepiece respirator fits the wearer and seals adequately to their face. This process helps identify unsuitable facepieces that should not be used.

[See surgical face mask.]

A term applied to fabrics that resist liquid penetration, often used interchangeably with ‘fluid-repellent’ when describing the properties of protective clothing or equipment. When used to describe a surgical mask this specifically refers to a type IIR surgical mask and not a type II surgical mask.

Surfaces of the environment which are commonly touched or come into contact with human hands. These are surfaces that are frequently more likely to be contaminated with bacteria or viruses, for example, doorknobs, tables, phones etc. which can then easily transfer to the user.

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General practitioner (your family doctor).

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The process of decontaminating your hands using either alcohol based hand rub or liquid soap and water.

Individual, single-use pieces of plastic or cloth fabric pre-moistened with cleansing products and intended for performing hand hygiene. These products may also contain antimicrobials agents.

Hazard group 4 infections cause severe human disease and are a serious hazard to employees; they are likely to spread to the community and there is usually no effective prophylaxis or treatment available.

A team of healthcare professionals whose role it is to protect the health of the local population and limit the risk of them becoming exposed to infection and environmental dangers.

Infections that occur as a result of medical care, or treatment, in any healthcare setting.

Waste produced as a result of healthcare activities, for example, soiled dressings or sharps.

In health and care settings the hierarchy of controls is a system used to identify risks and the appropriate controls to prevent the spread of infection. Control measures are considered and applied in order from most to least effective under the categories of elimination, substitution, engineering controls, administrative controls, and personal protective equipment (PPE), respectively.

A high consequence infectious disease (HCID) typically causes severe symptoms requiring a high level of care, with a high case-fatality rate, and there may not be effective prophylaxis or treatment. HCID are transmissible from human to human (contagious) and capable of causing large-scale epidemics or pandemics.

HFNC is an oxygen supply system capable of delivering up to 100% humidified and heated oxygen at a flow rate of up to 60 litres per minute.

Refers to sodium hypochlorite (bleach), a chlorine-based disinfectant and chlorine releasing agent. Sodium dichloroisocyanurate is another chlorine-based disinfectant in common use in care settings that may be referred to as ‘hypochlorite’, although this is technically incorrect the two products have identical uses and are equally effective.

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To provide immunity to a disease by giving a vaccination.

Any individual whose immune response is reduced or deficient, usually because they have a disease or are undergoing treatment. Individuals who are immunocompromised are more vulnerable to infection.

Cannot be penetrated by liquid.

Induction of sputum typically involves the administration of nebulised saline to moisten and loosen respiratory secretions (this may be accompanied by chest physiotherapy (percussion and vibration)) to induce forceful coughing.

The spread of infectious agents from one person to another via a contaminated object.

Invasion of the body by a harmful organism or infectious agent such as a virus, parasite, bacterium or fungus.

A specialist multidisciplinary team providing practical, clinical advice to staff and service users on IPC issues. This includes implementation of preventative work such as policy, guidance and education, as well as leading on the investigation and management of infection incidents such as data exceedances and outbreaks.

Any organism, such as a virus, parasite, bacterium or fungus, that is capable of causing an infection or infectious disease.

Linen that has been used by a patient who is suspected or confirmed to be infectious and or linen that is contaminated with blood and or other body fluids, for example faeces.

A medical device which penetrates the body, either through a body cavity or through the surface of the body. Central venous access devices, peripheral arterial lines and urinary catheters are examples of invasive devices.

A medical/healthcare procedure that penetrates or breaks the skin or enters a body cavity.

Physically separating patients to prevent the spread of infection.

An isolation suite comprises a single-bed room, en-suite and lobby either negative or positively ventilated. It is recommended that room should either positive or negative pressure and not both (interchangeable).

Isolation rooms/suites grouped together in a ward that includes a ventilated lobby at the ward entrance. Isolation wards can include isolation rooms ventilated under negative and positive pressure or exclusively of positively ventilated isolation rooms.

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Any living thing (organism) that is too small to be seen by the naked eye. Bacteria, viruses and some parasites are microorganisms.

The way that microorganisms spread from one person to another. The main modes or routes of transmission are airborne (aerosol) transmission, droplet transmission and contact transmission.

An incident in which the mucous membranes (eg mouth, nose, eyes) are exposed to blood/other body fluid.

The surfaces lining the cavities of the body that are exposed to the environment such as the lining of the mouth and nose.

A room that contains more than one bed. In NHS England, the preferred maximum number of beds in a multi-bed room is four. Multi-bed rooms require two clinical wash-hand basins and must have en-suite sanitary facilities.

Organisms (predominately bacteria) that are resistant to more than one class of antimicrobial agent.

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Ventilation which maintains permanent negative pressure between a lobby, room, and/or en-suite and adjacent environment, ie, air flow is from the outside adjacent space (eg, access corridor) into the room and then exhausted to the outside.

Isolation rooms/suites under negative pressure should be used to accommodate a patient known or suspected to be infected with a microorganism spread by the airborne (aerosol) route while the patient is considered infectious.

A synthetic rubber material used to make non-latex gloves.

Skin that is broken by cuts, abrasions, dermatitis, chapped skin, eczema etc.

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Exposure of healthcare workers or care staff to blood or body fluids in the course of their work.

When two or more individuals have the same infection, or more individuals than expected have the same infection. The cases will be linked by a place and a time period.

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Equipment an individual wears to protect themselves from risks to their health or safety, including exposure to infection agents. The level of PPE required depends on the:

A disease outbreak that occurs over a wide geographical area (such as multiple countries and/or continents) and typically affects a significant proportion of the population.

Any disease-producing infectious agent.

Placing a group of two or more patients (a cohort) with the same infection/strain in the same bay/ward. Cohorts are created based on clinical diagnosis, microbiological confirmation, epidemiology, and mode of transmission.

An injury caused by a sharp instrument or object such as a needle or scalpel, cutting or puncturing the skin.

In health and care settings physical distancing is the recommended distance that should be maintained between staff, patients and visitors unless mitigations are in place such as the use of PPE.

Ventilation which maintains permanent positive pressure between a lobby, room, and/or en-suite and adjacent environment, ie air flow is from the outside adjacent space (eg, access corridor) into the room and then exhausted to the outside.

Isolation rooms/suites under positive pressure should be used to accommodate a patient requiring protective isolation, eg immunocompromised patients.

These provide the first point of contact in the healthcare system and includes general practice, dentistry, community pharmacies etc.

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To put a needle or other sharp object back into its plastic sheath or cap.

Respiratory protection that is worn over the nose and mouth designed to protect the wearer from inhaling hazardous substances, including airborne particles (aerosols).

There are two types of respiratory protection that can be used: tight-fitting disposable FFP respirators and loose-fitting powered respirator hoods (TH2). FFP stands for filtering face piece.

There are three categories of FFP respirator: FFP1, FFP2 and FFP3. FFP3 and loose-fitting powered respirator hoods provide the highest level of protection and are recommended when caring for patients in areas where high risk AGPs are being performed.

[See FFP3.]

Respiratory symptoms include:

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A medical sharps device which has been designed to incorporate a feature or mechanism that minimises and/or prevents the risk of accidental injury. This includes needle-free devices or mechanisms on a needle, such as an automated re-sheathing device, that cover the needle immediately after use. Other terms include (but are not limited to) safety devices, safety-engineered devices and safer needle devices.

All sinks and furniture in a bathroom, such as a toilet, bath, shower etc.

Screening is a way of identifying apparently healthy individuals who may have an increased risk of a particular condition. The NHS offers a range of screening tests to different sections of the population.

Any bodily fluid that is produced by a cell or gland, such as saliva or mucous, for a particular function in the organism or for excretion.

Physically separating or isolating from other individuals.

A life threatening condition that arises when the body's response to a severe complication of infection, eg pneumonia (lung infection), injures its own tissues and organs. This can lead to multiple organ failure and death. Early recognition, treatment and management is key to successful patient outcomes.

A ‘sharp’ is a device or instrument used in healthcare settings with sharp points or edges, such as needles, lancets and scalpels which have the potential to cause injury through cutting or puncturing the skin.

See percutaneous injury.

In relation to valved respirators, a shroud refers to the material covering the valve outlet. The material must meet the same standards for fluid-resistance as a fluid resistant (Type IIR) surgical mask. A respirator with a shrouded valve can be used for the same activities as an unvalved respirator, that is to protect the wearer against splash and spray in addition to airborne infection risks.

A percutaneous, mucocutaneous exposure or non-intact skin (abrasions, cuts, eczema) exposure to blood/other body fluids from a source that is known (or later found to be) positive for a bloodborne virus infection.

A room with space for one patient and usually contains (as a minimum) a bed, a locker or wardrobe and a clinical wash-hand basin. Single-bed rooms may also include an en suite and / or ventilated lobby and be under positive or negative pressure.

Source control refers to use of well-fitting cloth masks, FRSMs, or respirators (must be unvalved or shrouded) to cover a person's mouth and nose to prevent spread of respiratory secretions when they are breathing, talking, sneezing, or coughing.

A form taken by fungi and some bacteria, eg Clostridioides difficile, that allows them to survive for long periods of time. Spores have thick walls and are highly resistant to the effects of heat, humidity, pressure and chemical disinfection.

SICPs are the basic IPC measures necessary to reduce the risk of transmitting infectious agents from both recognised and unrecognised sources of infection. Sources of (potential) infection include blood and other body fluids secretions or excretions (excluding sweat), non-intact skin or mucous membranes and any equipment or items in the care environment that could have become contaminated.

When staff care for one specific group of patients and do not move between different patient cohorts. Patient cohorts may include for example ‘symptomatic’, ‘asymptomatic and exposed’, or ‘asymptomatic and unexposed’ patient groups.

Free from live bacteria or other microorganisms

A disposable fluid-resistant mask worn over the nose and mouth to protect the mucous membranes of the wearer's nose and mouth from splashes and infectious droplets and also to protect patients. When recommended for infection control purposes a ‘surgical face mask’ typically denotes a fluid-resistant (Type IIR) surgical mask.

Also referred to as surgical hand antisepsis, surgical scrubbing is the term used to describe the process of hand hygiene required prior to performing a sterile or surgical procedure.

Way of closing bag by twisting the top of the bag (must not be more than two-thirds full), looping the neck back on itself, holding the twist firmly, and placing a seal over the neck of the bag (such as with a tag).

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A terminal clean is defined as: a procedure required to ensure that an area has been cleaned/decontaminated following transfer or discharge of a patient suspected or confirmed to be infected or colonised with an infectious pathogen (that is, alert organism or communicable disease) to ensure a safe environment for the next patient.

Additional precautions to be used in addition to SICPs when caring for patients with suspected or confirmed infection or colonisation.

Prioritisation of care according to severity using a validated tool. In this guidance those with respiratory symptoms should be prioritised for isolation/single room care while awaiting test results.

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Universal masking in health facilities is defined as the requirement for all persons (staff, patients, visitors, service providers and others) to wear a mask at all times except for when eating or drinking.

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A preparation of immunogenic material that is administered to stimulate the immune response of the body against an infectious agent.

Any medical instrument used to access a patient's veins or arteries such as a central venous access device or peripheral intravenous catheter.

Ventilation is a means of removing and replacing the air in a space. In its simplest form this may be achieved by opening windows and doors (natural ventilation) or may be achieved via a controllable (mechanical) method. Basic systems consist of a fan and either collection, (extraction) or distribution (supply) ductwork.

A room between the patient's bedroom and the access corridor, where the lobby to corridor and the lobby to bedroom doors open into the lobby and are fitted with door closers. Ventilated lobbies can be under negative or positive pressure ventilation.

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Hospital beds that are grouped into bed clusters, multi-bed rooms, single-bed rooms, or a combination of all three, with associated treatment and support facilities. In NHS England, the minimum recommended number of beds per ward is 24 and the maximum 32 beds per ward.

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