CIC (AAPC) key terms

The time between a person's exposure to an infectious agent and the appearance of the first symptoms or signs of illness. It helps determine monitoring and exclusion windows after exposure.

The span during which an infected person can transmit an infectious agent to others. It may begin before symptoms appear and can outlast them, guiding isolation and work-restriction decisions.

A model describing the six linked elements required for transmission: pathogen, reservoir, portal of exit, mode of transmission, portal of entry, and susceptible host. Breaking any link prevents new infection.

The route by which an infectious agent moves from a source to a host, such as contact, droplet, airborne, or vector-borne. Correctly identifying it determines which precautions and controls are needed.

A person lacking sufficient immunity or resistance to a pathogen, making infection more likely after exposure. Factors include age, immunosuppression, underlying disease, and breaches in skin or mucosal barriers.

Having a weakened immune system due to disease, medication, or treatment such as chemotherapy or transplant immunosuppression. Such patients face higher risk of infection and often more severe outcomes from common pathogens.

A microorganism that usually causes little or no harm in healthy people but can cause serious infection when host defenses are impaired. Examples include certain fungi, molds, and environmental bacteria.

An infection a patient acquires while receiving care for another condition that was not present or incubating at admission. Surveillance programs track these to target prevention efforts.

An infection occurring at or near a surgical incision within a defined time window after the operation, classified as superficial incisional, deep incisional, or organ/space. Surveillance requires standardized criteria and follow-up.

A primary bloodstream infection in a patient with a central venous catheter in place for a defined period, not explained by another source. Rates are commonly reported per 1,000 catheter days.

The total number of days patients have a specific invasive device, such as a ventilator or central line, summed across a population. Used as the denominator for device-associated infection rates.

A measure expressing the number of new infections in a population divided by a denominator such as patient days, device days, or procedures. Denominators must match the population at risk.

The proportion of a defined population that develops illness during a specified period, often used in outbreak investigations. It is calculated as cases divided by the population at risk.

A summary statistic comparing the number of observed infections to the number predicted from a national baseline, adjusted for risk factors. Values above one indicate more infections than expected.

A statistical method that accounts for differences in patient mix, such as severity of illness or device use, so infection rates can be fairly compared across units or facilities.

The occurrence of more cases of a disease than expected in a defined setting or population over a given time. Investigation aims to confirm the excess, find the source, and stop transmission.

Written criteria specifying the clinical, laboratory, and epidemiologic features that classify a person as having the condition under investigation. It must be applied consistently to count and compare cases.

A graph plotting the number of cases over time during an outbreak. Its shape helps infer the mode of transmission, likely exposure period, and whether the outbreak is point-source or continuing.

The standardized criteria a facility uses to decide whether a patient event counts as an infection for monitoring purposes. Consistent definitions allow valid comparison of rates over time.

Basic infection prevention practices applied to all patients regardless of diagnosis, including hand hygiene, gloves, gowns, masks, and safe handling of sharps and body fluids. They are the foundation of transmission prevention.

Additional precautions used beyond standard precautions for patients with known or suspected contagious pathogens, categorized as contact, droplet, or airborne. Choice depends on the pathogen's mode of transmission.

Measures used for pathogens spread by direct or indirect contact, typically requiring gloves and gown for room entry and often dedicated equipment. Examples include multidrug-resistant organisms and Clostridioides difficile.

Measures for pathogens spread by large respiratory droplets generated during coughing or sneezing, requiring a mask for close contact and often a private room. Examples include influenza and pertussis.

Measures for pathogens that remain infectious while suspended in small particles over long distances, requiring an airborne infection isolation room and fitted respiratory protection. Examples include tuberculosis and measles.

A single-patient room designed with negative pressure relative to surrounding areas and frequent air exchanges, often with exhaust directed outside or filtered. It contains aerosols from patients with airborne pathogens.

Cleaning hands with soap and water or an alcohol-based product at the correct moments to remove or kill transient microorganisms. It is the single most effective routine measure for preventing transmission.

Barrier items such as gloves, gowns, masks, respirators, and eye protection worn to prevent contact with infectious materials. Selection is based on the anticipated exposure and transmission route.

A formal procedure verifying that a specific respirator model forms an adequate seal on an individual's face. It is required before use and repeated periodically per program policy.

A microorganism resistant to multiple classes of antimicrobial drugs, limiting treatment options and increasing risk of severe infection. Examples include MRSA, VRE, and resistant gram-negative bacteria.

A coordinated program promoting appropriate antibiotic selection, dose, duration, and route to improve outcomes and reduce resistance and adverse effects. Infection prevention and stewardship programs often collaborate.

Treatment or vaccination given after exposure to a pathogen to prevent infection or reduce its severity. Decisions depend on the pathogen, exposure type, and the person's immune status.

A specific event in which a person contacts blood, body fluids, or infectious material through a needlestick, splash, or similar route. It triggers evaluation, source testing, and possible prophylaxis.

A virus or other microorganism transmitted through contact with infected blood or certain body fluids, notably hepatitis B, hepatitis C, and HIV. Occupational programs focus on vaccination, safe devices, and exposure follow-up.

A policy requiring healthcare personnel to have documented immunity or vaccination against specified diseases, such as hepatitis B, measles, and influenza, as a condition of work. It protects staff and patients.

The physical removal of soil, organic matter, and many microorganisms from a surface or device using detergent and mechanical action. It generally precedes disinfection or sterilization because soil reduces their effectiveness.

A process that eliminates many or all pathogenic microorganisms on inanimate objects, except bacterial spores, using chemical or physical agents. Levels range from low to high depending on the intended use.

A process that kills all microorganisms except high numbers of bacterial spores, used for semicritical items such as endoscopes that contact mucous membranes. It requires thorough prior cleaning.

A validated process that destroys or eliminates all forms of microbial life, including bacterial spores, on an item. It is required for critical items entering sterile body sites or the vascular system.

A medical device that enters sterile tissue or the vascular system, such as a surgical instrument or implant, and therefore must be sterilized before use. Examples also include urinary and intravascular catheters.

A device that contacts intact mucous membranes or nonintact skin without entering sterile areas, such as a flexible endoscope or laryngoscope blade. These require at least high-level disinfection after cleaning.

An object that contacts only intact skin, such as a blood pressure cuff or bed rail, and does not penetrate mucous membranes. These generally require cleaning and low-level disinfection when soiled.

A designated work area kept free of microorganisms during an invasive procedure by using sterile drapes, supplies, and technique. Breaks in technique contaminate the field and increase infection risk.

The number of times the total volume of air in a room is replaced in one hour. It is a key engineering parameter for ventilation, dilution of airborne contaminants, and pressure relationships.

A room maintained at higher pressure than adjacent spaces so air flows outward, protecting its occupant from incoming contaminants. It is used for severely immunocompromised patients such as transplant recipients.