Infection Control in Healthcare Settings

Flashcards covering basic principles, definitions, strategies, and historical context of infection control in healthcare and dental settings based on chapter 12 of Marsh & Martin’s Oral Microbiology.

Physical strategies

Methods of infection control involving sterilisation and disinfection.

Chemotherapeutic

The use of drugs to kill or inhibit the growth of microorganisms.

Immunisation

The use of antigens from a specific microbe to generate a protective immune response.

Infection Control

Processes and precautions taken to control the spread of infection.

Typhoid Mary (Mary Mallon, 1869–1938)

The first identified asymptomatic carrier of Salmonella typhi in the USA who infected at least 53 people as a cook.

Direct Transmission

Spread of infection through contact with infectious lesions/skin infections, droplets from coughing/sneezing at $< 1\text{ metre}$, or exchange of bodily fluids.

Indirect Transmission

Spread of infection via pathogens carried $> 1\text{ metre}$ (airborne) or through contaminated objects known as fomites.

Fomites

Contaminated objects such as instruments, clothing, taps, door handles, and keyboards that can transmit pathogens indirectly.

Cleaning

The mechanical removal of material from the surface of an object, usually using detergent and water.

Disinfection

The destruction or removal of most microorganisms; it usually kills bacteria but may not kill spores and viruses.

Disinfectant

A chemical suitable for use on inanimate objects for the purpose of removing or killing microorganisms.

Antiseptic

A chemical disinfectant suitable for use on skin or living tissue that kills or removes harmful organisms without damaging tissues.

Sterilisation

The complete destruction or removal of ALL microorganisms including spores and viruses.

Sterile

A state of being free of all living organisms.

Alcohols (< 100\text{%})

Antiseptics that dissolve lipids in the cell wall/plasma membrane and require water to denature proteins; used for skin wipes and venipuncture prep.

Chlorhexidine

An antiseptic that disrupts the plasma membrane, has residual activity, and possesses low toxicity; widely used for handwashing.

Iodine-containing (e.g. povidone-iodine)

Antiseptics that oxidise microorganism components; used in mouthwash and for healing oral wounds.

Autoclaves (Moist Heat Sterilisers)

Devices that replace air with pressurised steam to achieve sterilisation, such as at $121^{\text{o}}C$ for $15\text{ minutes}$ or $134^{\text{o}}C$ at $2.25\text{ bar}$ for $3\text{ minutes}$.

Gamma ($\gamma$) irradiation

A sterilisation method used for anaesthetics, syringes, implants, and single-use medical supplies.

Critical Items

Spaulding classification for items that penetrate sterile tissue, body cavities, or the bloodstream (e.g., surgical instruments) which require sterilisation.

Semi-critical Items

Spaulding classification for items that contact mucous membranes or non-intact skin (e.g., mouth mirrors) requiring single-use, sterilisation, or high-level chemical disinfection.

Non-critical Items

Spaulding classification for items that contact intact skin only (e.g., X-ray heads) requiring cleaning and decontamination.

Blood-Borne Viruses (BBVs)

Viruses such as HBV, HCV, and HIV which are the main focus of infection control in dental settings.

Standard Precautions

The practice of treating ALL patients as potentially infectious at ALL times to break the chain of infection.

Ignaz Semmelweis

Historical figure who demonstrated in the 1840s that chlorine handwashing dramatically reduced childbed fever mortality.

Personal Protective Equipment (PPE)

Components such as gloves, masks, eye protection, and gowns that protect skin and mucous membranes from infectious spray or spatter.