Infection control is a structured approach designed to prevent the spread of harmful microorganisms, such as bacteria, viruses, and fungi, within various environments. These microorganisms cause infections by following a defined chain of transmission, moving from a source to a susceptible person. To effectively break this chain, public health and healthcare institutions rely on a three-pronged strategy. This framework focuses on controlling pathogens at the source, blocking their movement, and eliminating them from objects and surfaces.
Maintaining Cleanliness Through Aseptic Practices
The first method of infection control focuses on reducing the overall number of pathogens in a given environment through specific, clean techniques. These practices, known broadly as asepsis, prevent contamination by minimizing the transfer of microorganisms. The single most effective action within this category is proper hand hygiene, which involves thoroughly washing hands with soap and water or using an alcohol-based hand rub to significantly decrease microbial load on the skin.
Aseptic practices also extend to human behavior aimed at containing the source of pathogens, known as respiratory etiquette. This involves covering the mouth and nose with a tissue or the elbow when coughing or sneezing to prevent the expulsion of droplets containing infectious agents. Prompt disposal of used tissues and subsequent hand hygiene further limits the spread of respiratory illnesses.
Maintaining a clean immediate environment is another aspect of this method, often referred to as “clean technique” in routine care settings. This includes wiping down frequently touched surfaces, like doorknobs and bedside tables, to reduce the reservoir of microbes that can be easily transferred by contact. The goal is not complete eradication but rather managing microbial populations to a level that minimizes the risk of infection.
Blocking Transmission with Barrier Protection
The second category involves the use of physical barriers to interrupt the pathway of transmission between a source and a person. Personal Protective Equipment (PPE) forms the largest part of this strategy, acting as a physical shield to protect the skin, mucous membranes, and clothing from infectious materials. Gloves prevent direct contact with contaminated surfaces or body fluids, while fluid-resistant gowns shield the wearer’s clothing and torso.
Masks and respirators are designed to block the inhalation of airborne or droplet-borne pathogens. Protective eyewear, such as goggles or face shields, prevents infectious droplets from entering the body through the eyes. This equipment must be worn and removed in a specific order to ensure that the user does not contaminate themselves or the environment during the process.
Beyond personal equipment, barrier protection also encompasses environmental controls like patient isolation. This involves placing an infected or potentially infected person in a single room or cohorting them with others who have the same condition. This separation physically contains the pathogens. Specialized ventilation systems, such as negative pressure rooms, can be used to prevent airborne particles from escaping the area, blocking their transmission to the wider environment.
Eliminating Pathogens via Sterilization and Disinfection
The third method centers on the application of chemical or physical processes to destroy microorganisms on inanimate objects. This approach is divided into two levels of microbial destruction: disinfection and sterilization. Disinfection uses chemical agents to eliminate nearly all pathogenic microorganisms on surfaces, but it does not reliably kill bacterial spores, which are highly resistant microbial forms.
Disinfection is commonly used on environmental surfaces, such as floors, walls, and non-invasive medical equipment. Depending on the agent’s strength, it may be categorized as low, intermediate, or high-level. Examples of disinfecting agents include chlorine compounds, quaternary ammonium compounds, and certain alcohol solutions.
Sterilization is a more stringent process that destroys all forms of microbial life, including the highly resilient bacterial spores. This complete eradication is achieved using intense physical methods, such as pressurized saturated steam in an autoclave, or high-level chemical sterilants and gases. Sterilization is reserved for objects that enter sterile tissue or the vascular system, such as surgical instruments, implants, and needles.