3.1 Asepsis, Infection Control & Sterilization

Infection control is the first task area in AMT's Clinical Medical Assisting work area, which accounts for 55% of the RMA exam (115 questions). It is one of the most critical topics for a medical assistant.

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Types of Asepsis

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Chain of Infection

The chain of infection describes the six elements required for infection to spread. Breaking any single link prevents transmission:

1. Infectious agent: The pathogen (bacteria, virus, fungus, parasite)
2. Reservoir: Where the pathogen lives and multiplies (humans, animals, fomites, water, food)
3. Portal of exit: How the pathogen leaves the reservoir (respiratory secretions, blood, skin, GI tract, GU tract)
4. Mode of transmission: How the pathogen travels to the new host
   • Direct contact: Touching, kissing, sexual contact
   • Indirect contact: Fomites (contaminated objects), vectors (insects), vehicles (food, water, air)
   • Droplet: Large respiratory droplets (< 3 feet, coughing, sneezing)
   • Airborne: Small particles suspended in air (> 3 feet, remain airborne for extended periods)
5. Portal of entry: How the pathogen enters the new host (respiratory tract, breaks in skin, mucous membranes, bloodstream)
6. Susceptible host: A person with insufficient immunity to resist infection

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Standard Precautions (Apply to ALL Patients)

Standard Precautions are used for every patient encounter regardless of known or suspected infection status:

• Hand hygiene: Before and after every patient contact, after removing gloves
• Gloves: When touching blood, body fluids, mucous membranes, non-intact skin
• Masks, eye protection, face shields: When splashing or spraying of body fluids is anticipated
• Gowns: When contact with blood or body fluids may soil clothing
• Safe injection practices: Use single-use, single-patient vials; never reuse needles or syringes
• Respiratory hygiene/cough etiquette: Cover coughs/sneezes, offer masks to symptomatic patients
• Sharps safety: Use safety-engineered devices; dispose in sharps containers immediately after use

Transmission-Based Precautions

Hand Hygiene

Hand hygiene is the single most important measure to prevent healthcare-associated infections.

When to Perform Hand Hygiene (WHO "5 Moments"):

1. Before touching a patient
2. Before a clean/aseptic procedure
3. After body fluid exposure risk
4. After touching a patient
5. After touching patient surroundings

Hand Washing with Soap and Water

• Required when hands are visibly soiled or contaminated with blood/body fluids
• Required after caring for patients with C. difficile or Norovirus (spore-forming organisms)
• Use warm water, apply soap, lather for at least 20 seconds, rinse, and dry with paper towels
• Use paper towel to turn off faucet

Alcohol-Based Hand Rub (ABHR)

• Preferred for routine hand hygiene when hands are NOT visibly soiled
• Apply enough product to cover all surfaces of hands and fingers
• Rub until dry (approximately 20 seconds)
• NOT effective against spore-forming organisms (C. difficile) -- use soap and water

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Personal Protective Equipment (PPE)

Donning Order (Putting ON):

1. Gown (tie at neck and waist)
2. Mask or N95 respirator (fit snugly over nose and mouth)
3. Eye protection (goggles or face shield)
4. Gloves (extend over gown cuffs)

Doffing Order (Taking OFF):

1. Gloves (peel off without touching exterior; discard)
2. Eye protection (remove by headband, not lens)
3. Gown (unfasten, pull away from body, fold contaminated side in)
4. Mask/respirator (remove by elastic bands, not front)
5. Perform hand hygiene immediately

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Sterilization Methods

Sterilization Quality Assurance

Autoclave Loading Guidelines

• Leave space between packs for steam penetration
• Place items on their sides with lids open (jars, containers)
• Do not overload the autoclave
• Use autoclave tape on the outside of each pack
• Include a chemical indicator strip inside each pack
• Allow items to dry completely before removal and storage
• Label sterilized items with date, initials, and contents
• Shelf life depends on the wrapper and storage conditions: with event-related storage, a pack stays usable until it is torn, wet, punctured, or its seal is broken; with time-related storage, label each pack with an expiration date and reprocess it once that date passes (CDC)