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Glossary of Terms

Administrative controls are measures that the administration of a healthcare facility puts into place to help protect health workers, patients/ residents, and visitors from acquiring infections.
This definition includes antibacterials, antivirals, antiprotozoals, antifungals, antiseptics, and disinfectants. 
A chemical agent that, when applied to living tissue, will destroy or inhibit the reproduction of microorganisms.
It is the spread of an infectious agent caused by the dissemination of droplet
that remain infectious when suspended in air over long distances and time.
Aseptic non-touch technique (ANTT) is applied to prevent the transfer of microorganisms from the healthcare worker, items and equipment used during the procedure or the immediate environment to the patient during the invasive clinical and surgical procedures to prevent healthcare-associated infections.
Infection which does not display any clinical signs and symptoms but may still be capable of transmitting disease or microorganisms.
A person with symptoms.
A person (host) who harbours a microorganism (agent) but does not necessarily display clinical signs/ symptoms of the disease. Depending on the type of pathogens, a carrier may shed organisms into the environment intermittently or continuously and act as a potential reservoir or source of infection.
The administration of antimicrobial agents to prevent the development of an infection or the progression of infection to active manifest disease.

The removal, usually with detergent and water, of adherent visible soil, blood, protein substances, microorganisms, and other debris from the surfaces, instruments, devices, and equipment, by a manual or mechanical process that prepares the items for safe handling and/or further decontamination, i.e. before using heat or chemicals, disinfection or sterilisation.

A group of infected or colonised neonates with the same microorganism grouped in a designated area of a unit.
The practice of assigning specific personnel to care only for patients who are known to be exposed to or infected with the same microorganism. Such personnel would not participate in caring for patients who had not been exposed to or infected with that microorganism.
Infection is defined as a community-acquired if the onset of symptoms occurred in the community or within 48 hours of admission to a healthcare facility. The time frame is modified for infections with incubation periods less than 48 h (e.g. gastroenteritis caused by Norovirus virus) or longer (e.g. viral hepatitis B and C). In addition, it is important to differentiate between community-acquired infection (infection acquired in the community and patients who had no direct or indirect contact with any healthcare facilities) and community-onset infection, where the patient was recently discharged from the healthcare facility, and they should be counted as a part of healthcare-associated infections.
The presence of microorganisms at a body site(s) without symptoms or clinical manifestations of illness or infection. Colonisation may be a form of carriage and a potential transmission source.
A microorganism resident in or on a body site without causing clinical infection.
An exposed individual who might have been infected through transmission from another host or the environment.
Infection is caused by physical contact of a susceptible host with people or objects. Direct contact transmission involves direct body-surface-to-body-surface contact and the physical transfer of microorganisms between an infected or colonised person and a susceptible host. Indirect contact transmission involves contact of a susceptible host with a contaminated intermediate object (e.g., contaminated hands) that carries and transfers the microorganisms.
The presence of microorganisms on a surface or in a fluid or material.
The practice of covering the mouth and nose during breathing, coughing, or sneezing (such as wearing a surgical mask, cloth mask, covering the mouth with tissues, a sleeve, flexed elbow or a hand, followed by hand hygiene) to reduce the dispersal of respiratory secretions that may contain infectious particles.
An infection transmitted from one patient to another or from a staff member or the environment to another patient
The use of physical or chemical means to remove, inacti­vate, or destroy pathogenic microorganisms from a surface or item to the point where they are no longer capable of transmitting infectious particles, and the surface or item is rendered safe for handling, use, or disposal. This term covers cleaning, disinfection, and/or sterilisation.
A chemical agent that, when applied to living tissue, will destroy or inhibit the reproduction of microorganisms.
A chemical agent that, under defined conditions, is capable of disinfection. A substance that is recommended by its manufacturer for application to an inanimate object to kill a range of microorganisms.
Infection is caused by the dissemination of droplets. Droplets are primarily generated from an infected (source) person during coughing, sneezing and talking. Transmission occurs when microorganisms contained in these droplets are propelled (usually < 1 meter or  ~ 3 feet) through the air and deposited on another person's conjunctivae, mouth, nasal, throat or pharynx mucosa. Most of the volume (> 99 per cent comprises large droplets that travel short distances (< 1 meter or  ~ 3 feet ) and do not remain suspended in the air.
They are used to soften and smooth the scales of the skin and prevent flakiness of the skin. In addition, they also act as an occlusive agent– substances that provide a layer of protection that helps prevent loss of water/ moisture from the skin.
Microorganisms originating from the patient's own body, which may cause infection in another body site.
The usual level or presence of an agent or disease in a defined population during a given period.
An unusual, higher than expected level of infection or disease by a common agent in a defined population in a given period.
Microorganisms originating from a source or reservoir transmitted to a person, i.e. contact, airborne, droplet, ingestion, inoculation, vertical, sexual, or vector-borne.

Exposure-prone procedures (EPPs) include procedures where the worker's gloved hands may be in contact with sharp instruments, needle tips or sharp tissues inside a patient's open body cavity, wound or confined anatomical space, where the hands or fingertips may not be completely visible at all times. However, other situations, such as pre-hospital trauma care, should be avoided by HCWs restricted from performing EPPs, as they could also result in the exposure of the patient's open tissues to the blood of the worker. The definition of EPPs given above embraces a wide range of procedures in which there may be very different levels of risk of bleed-back. A risk-based categorisation of clinical procedures has been developed, including procedures where there is negligible risk of bleed-back (non-EPP) and three categories of EPPs with increasing risk of bleedback. Please refer to the definitions and examples of three categories of EPPs in Emergency Healthcare Workers, Exposure Prone Procedures (EPPs) and the Exposure Prone Environment. Public Health England, London: 2017.

The use of a qualitative or a quantitative method to evaluate the fit of a specific manufacturer, model, and size of the respirator (FFP3) on an individual.
An inanimate object that can act as an intermediate source of infecting organisms, e.g., equipment used for more than one patient that has not decontaminated between uses.
Refers to infections associated with healthcare delivery in any setting (e.g. hospitals, long-term care, and ambulatory settings). This term reflects that some patients are going through various healthcare facilities, and it is not always possible to establish, with certainty, when the primary source of infection was acquired by these patients. This term replaces both hospital-acquired infections and nosocomial infections.
Staff involved in direct patient care, i.e. who have regular clinical contact with patients. This includes doctors, dentists, midwives and nurses, paramedics and ambulance drivers, occupational therapists, physiotherapists, and radiographers. Students and trainees in these disciplines and volunteers working with patients must also be included.
All people primarily engaged in actions with the primary intent of enhancing health. This includes health service providers, such as doctors, nursing and midwifery professionals, public health professionals, technicians (laboratory, health, medical, and non-medical), personal care workers, healers, and practitioners of traditional medicine. It also includes health management and support workers, such as cleaners, drivers, hospital administrators, district health managers, social workers and other occupational groups in health-related activities. This group includes those who work in acute care facilities and long-term care, public health, community-based care and other occupations in the health and social care sectors.
The  High-risk body fluids include blood, amniotic fluid, semen, vaginal secretions, human breast milk, cerebrospinal fluid, peritoneal fluid, pleural fluid, pericardial fluid, synovial fluid, saliva in association with dentistry (likely to be contaminated with blood, even when not visibly so), exudative or other tissue fluid from burns or skin lesions, and unfixed tissues and organs.
Items in close contact with a break in the skin or mucous membrane or which have been introduced into a sterile body area (e.g. surgical instruments, dressings, catheters, and prosthetic devices). The items in this category must be sterile before they are used on a patient. The recommended decontamination method is sterilisation.
A patient who cannot usually respond to an infection due to an impaired or weakened immune system. A patient whose immune system is compromised due to various conditions (congenital deficiency, nutrition-deprived states, etc.)
A patient becomes or is made to suppress their immune system by the use of chemotherapy and/or radiotherapy for the treatment of cancer or the use of immunosuppressive drugs after an organ transplant to prevent graft rejection.

The ratio of the number of new cases of infection or disease in a defined population, in a given period, to the number of individuals at risk in the population.

in the population.
Items that make direct contact with intact mucous membranes. Semi-critical items need not be sterile when used, although this is desirable, they need to be free of the common vegetative microorganisms. The recommended decontamination method is disinfection, preferably by moist heat.
Any procedure that pierces the skin or mucous membranes or enters a body cavity or organ. This includes surgical entry into tissues, cavities, or organs or repair of traumatic injuries.
The number of new cases of a disease (or event) occurring in a specified time.
The time interval between initial exposure to the infectious agent and the appearance of the first signs or symptoms of the disease in a susceptible host.
The first case to be recognised in a series of transmissions of an infective agent in a host population.
The host's reaction to invasion by microorganisms which can cause damage to body tissue by poisonous substances (e.g. toxins) released by the microorganisms.
Any procedure that pierces the skin or mucous membranes or enters a body cavity or organ. This includes surgical entry into tissues, cavities, or organs or repair of traumatic injuries.
Include urine, vomit (unless visibly stained), saliva (non-dentistry associated), and faeces.
Objects that make contact with intact skin (e.g.chairs, baths, washing bowls, toilets, and bedding). The recommended decontamination method is cleaning and drying. Disinfection is necessary if there is a known infection risk.
According to the WHO, a medical device means any instrument, apparatus, implement, machine, appliance, implant, reagent for in vitro use, software, material, or another similar or related article, intended by the manufacturer to be used, alone or in combination, for human beings, for one or more of the specific medical purpose(s).
The normal human microbial flora (also called microbiota ) comprises microbes found commonly on or in humans. In general, the normal flora lives, multiplies, and dies without adverse effects on the host.
A microscopic entity capable of replication. These include bacteria, viruses, fungi, and protozoa.
A chemical agent that, when applied to living tissue, will destroy or inhibit the reproduction of microorganisms.
Used to denote airflow, which is negative in relation to surrounding air pressure. It is usually created by mechanical airflow devices (e.g. exhaust fans). Infected patients are isolated in the room to prevent the transmission of specific pathogens transmitted by the airborne route.
A microorganism capable of producing disease in a susceptible host.
The power of an infectious agent or microorganism to produce disease in a susceptible host.
The air pressure is higher than in the adjoining areas in a positive air pressure isolation room. Therefore, positive pressure isolation prevents airborne pathogens from entering the room. These rooms are used for patients with immunosuppressed patients.
The Ratio of the total number of individuals who have a disease at a particular time in the population at risk of having the disease.
A small proteinaceous infectious unit that appears to cause transmissible spongiform encephalopathies.
A widespread occurrence of an infectious disease over a whole country or the world at a particular time.
Any animate or inanimate focus in the environment where an infectious agent may survive and multiply, which may be a potential source of infection.
An item designated or intended by the manufacturer as suitable for reprocessing and re-use.

Special type of closely fitted face cover with the capacity to filter

particles to protect the wearer against inhaling infectious droplet nuclei, e.g.

tuberculosis. The FFP2 and FFP3 respirator has a filter efficiency level of 94 % and 99 %, respectively, against 0.4 μm particles and is tested against both an oil and a non-oil aerosol.

The development of antibodies not previously present, resulting
from primary infection.

Any objects capable of inflicting penetrating injury, including needles,
scalpel blades, wires, trochors, auto lancets, stitch cutters, etc.
Items designated by the manufacturer for single-use only
An antiseptic intended for application to intact, healthy skin to prevent the transmission of transient or resident skin bacteria.
The physical separation of an infected or colonised host from the remainder of the 'at-risk' population in an attempt to prevent transmission of the specific agent to other individuals and patients.
A single case which has not been associated with other cases, excreters, or carriers in the same period of time.
The aim of standard precautions is to protect health workers and patients by reducing the risk of microorganisms transmission from recognised and unrecognised sources. They are the minimum standard of infection prevention and control practices that should be used by all healthcare workers, during the care of all patients, at all times and in all settings. When applied consistently, standard precautions can prevent the transmission of microorganisms between patients, health workers and the environment.
Free from all living microorganisms and spores.
The destruction of all microorganisms, including bac­terial spores. For practical reasons, a process can be said to sterilise if it can kill or remove 106 spores of a type specified to test the process within the time specified.
A person not possessing sufficient resistance (or immunity) to an infectious agent to prevent them from contracting an infection when exposed to the agent.
Systematic collection, analysis, and interpretation of data on specific events (infections) and diseases, followed by dissemination of that information to those who can improve the outcomes.
A person (host) infected with a bacterium, virus, or other microorganism that infects disproportionately more secondary contacts than other hosts also infected with the same disease.
They are used in addition to standard precautions for patients with known or suspected infection or colonisation with transmissible and/or epidemiologically significant pathogens. The type of transmission-based precautions assigned to a patient depends on the transmission route of the microorganisms i.e. contact, droplet and airborne.
Triage identifies those who require immediate medical intervention and also identifies mothers and neonates with suspected infection.
The intrinsic ability of a microorganism to infect a host and produce disease.