The chain of infection
Infections spread through a six-link chain. Breaking any single link stops transmission:
- Infectious agent — the pathogen (bacteria, virus, fungus, prion).
- Reservoir — where it lives and multiplies (humans, equipment, water).
- Portal of exit — how it leaves (blood, secretions).
- Mode of transmission — contact, droplet, airborne, vehicle, vector.
- Portal of entry — how it enters a new host (broken skin, mucous membranes).
- Susceptible host — a person at risk.
Proper decontamination and sterilization break the chain by eliminating the reservoir and the mode of transmission on reusable devices.
Standard precautions
Standard precautions treat all blood and body fluids as potentially infectious, regardless of a patient's diagnosis. They include hand hygiene, appropriate PPE, safe injection practices, and safe handling of contaminated equipment and surfaces.
🔑 Hand hygiene
Hand hygiene is the single most important measure to prevent the spread of infection. Wash with soap and water when hands are visibly soiled; otherwise an alcohol-based hand rub is acceptable.
Asepsis & sterile technique
- Medical asepsis — reduces the number and spread of microorganisms ("clean technique").
- Surgical asepsis — eliminates all microorganisms from an object or area ("sterile technique").
Sterile processing technicians support surgical asepsis by guaranteeing that every item leaving the department is sterile and that packaging maintains sterility until the point of use.
Bloodborne pathogens & exposure control
OSHA's Bloodborne Pathogens Standard requires an exposure control plan, hepatitis B vaccination offered to at-risk staff, engineering controls (sharps containers, splash guards), and post-exposure follow-up.
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