Infection control is not optional and it is not just a box-checking exercise. Every patient who walks through a clinical door is either at risk of acquiring an infection or potentially carrying one. Your job is to break the chain of transmission. This article covers the core principles every MA needs to know — and that the CCMA exam tests directly.
The Chain of Infection
Before you can break transmission, you need to understand how infection spreads. Six links form the chain:
- Infectious agent — bacteria, virus, fungus, parasite
- Reservoir — where the pathogen lives (patient, equipment, environment)
- Portal of exit — how it leaves the reservoir (blood, respiratory droplets, feces)
- Mode of transmission — contact, droplet, airborne, vector-borne
- Portal of entry — how it enters a new host (broken skin, mucous membranes, respiratory tract)
- Susceptible host — the new person at risk
Every infection control measure targets one or more of these links. Hand hygiene breaks transmission. PPE protects the portal of entry. Sterilization eliminates the infectious agent at the reservoir.
Standard Precautions
Standard precautions treat all blood, body fluids, non-intact skin, and mucous membranes as potentially infectious — regardless of the patient's known diagnosis. This replaced the older "universal precautions" framework and expanded it to include additional fluid types.
Standard precautions apply to every patient encounter. They include:
- Hand hygiene before and after patient contact
- Appropriate PPE based on anticipated exposure
- Safe needle handling and sharps disposal
- Respiratory hygiene and cough etiquette
- Safe injection practices (one needle, one syringe, one patient)
- Proper handling and disposal of contaminated equipment
Transmission-based precautions (contact, droplet, airborne) are added on top of standard precautions for patients with known or suspected specific infections.
Hand Hygiene
Hand hygiene is the single most effective infection control measure. Two methods are used in clinical settings: soap and water, and alcohol-based hand rub (ABHR).
Soap and Water
Required when hands are visibly soiled, before eating, after using the restroom, and after caring for patients with Clostridioides difficile (C. diff) or norovirus. ABHR does not kill C. diff spores. Lather for at least 20 seconds, covering all surfaces including between fingers, thumbs, and under nails. Rinse and dry thoroughly.
Alcohol-Based Hand Rub (ABHR)
Preferred for most routine clinical hand hygiene when hands are not visibly soiled. Apply to all surfaces of the hands and rub until dry — this typically takes 20-30 seconds. Faster than soap and water, and at least as effective for most pathogens. Convenient at point-of-care with wall-mounted dispensers.
When to perform hand hygiene: before touching a patient, before clean or aseptic procedures, after body fluid exposure risk, after touching a patient, after touching patient surroundings. The WHO calls these the "5 Moments."
Personal Protective Equipment (PPE)
PPE selection is based on the type of exposure anticipated. Know what each type protects against and when to use it.
- Gloves: Any time contact with blood, body fluids, mucous membranes, or non-intact skin is anticipated. Change between patients. Change within a patient encounter if moving from a contaminated to a clean body site. Gloves do not replace hand hygiene.
- Gown: When splashing or spraying of blood or body fluids is likely, or when contact precautions require it. Cover the front of the body and arms completely. Tie at the neck and waist.
- Mask: Surgical masks protect against large respiratory droplets and splatter. N95 respirators filter at least 95% of airborne particles — required for patients on airborne precautions (TB, measles, varicella).
- Eye protection: Goggles or face shield when splash or spray of blood or body fluids to the eyes is possible.
Donning order: gown, mask/respirator, goggles/face shield, gloves. Doffing order is roughly the reverse — gloves first (most contaminated), then goggles, gown, mask last. Perform hand hygiene after removing each item and again after all PPE is removed.
Medical Asepsis vs. Surgical Asepsis
These two concepts get confused on exams. Know the difference.
Medical asepsis (clean technique) means reducing the number of microorganisms to a safe level. It does not eliminate all organisms. Used for routine patient care: taking vital signs, giving oral medications, wound assessment without sterile procedures. Hand hygiene and clean gloves are the core tools.
Surgical asepsis (sterile technique) means eliminating all microorganisms including spores from an object or area. Used whenever the skin barrier is broken — injections, catheter insertion, surgical procedures, sterile dressing changes. Any item that will enter a sterile body cavity or contact an open wound must be sterile.
Autoclave Sterilization
The autoclave is the workhorse of sterilization in clinical settings. It uses pressurized steam to kill all microorganisms including bacterial spores.
Standard parameters:
- Temperature: 250°F (121°C) for gravity displacement; 270°F (132°C) for pre-vacuum
- Time: 15-30 minutes depending on load type and cycle
- Pressure: approximately 15 psi above atmospheric pressure
Items must be clean before autoclaving — organic material (blood, tissue) can block steam penetration and prevent sterilization. Wrap items in autoclave-approved packaging. Load loosely so steam can circulate. Do not stack items tightly.
Use autoclave indicator tape or chemical indicator strips with every load. The tape changes color when exposed to steam. This confirms the load was processed — it does not guarantee sterilization. Biological indicators (spore tests) are the gold standard for confirming sterilization and should be run at least weekly.
Chemical Sterilization
Used for heat-sensitive instruments that cannot go through the autoclave. Common agents include glutaraldehyde and hydrogen peroxide gas plasma. Items must be fully immersed for the required contact time — check the manufacturer's instructions for each chemical agent. Chemical sterilization is slower than autoclaving and requires good ventilation and appropriate PPE due to chemical hazards.
Disinfection is not sterilization. High-level disinfectants like glutaraldehyde can achieve sterilization with extended contact time but are more commonly used for high-level disinfection of semi-critical items (equipment contacting mucous membranes but not sterile tissue).
Biohazard Waste Disposal
Regulated medical waste (biohazardous waste) requires specific disposal procedures to protect healthcare workers, patients, and the public.
- Sharps: Needles, lancets, scalpels, broken glass contaminated with blood. Must go in puncture-resistant, leak-proof sharps containers. Never recap needles two-handed. Use the one-hand scoop technique if recapping is absolutely necessary. Containers should be sealed and replaced when 3/4 full.
- Liquid blood and body fluids: Can generally be disposed in the sanitary sewer with facility approval. Check local regulations.
- Solid biohazardous waste: Items saturated or dripping with blood — gauze, draping, contaminated materials. Placed in red biohazard bags. Labeled with the biohazard symbol.
- Pathological waste: Tissues and body parts. Separate handling per facility and regulatory requirements.
OSHA Bloodborne Pathogen Standard
OSHA's Bloodborne Pathogen Standard (29 CFR 1910.1030) requires employers to protect workers from exposure to blood and other potentially infectious materials (OPIM). Key requirements:
- Written Exposure Control Plan — updated annually
- Use of engineering controls (safety-engineered sharps, needleless systems)
- Work practice controls (one-hand recapping, no bending/breaking needles)
- Provision and use of PPE at no cost to employees
- Hepatitis B vaccine offered to all at-risk employees
- Post-exposure evaluation and follow-up after needlestick or splash
- Annual bloodborne pathogen training
- Sharps injury log maintenance
If you have a needlestick or splash exposure, report it immediately. Do not wait. Wash the site thoroughly with soap and water. Time matters for post-exposure prophylaxis (PEP) for HIV — it must be started within 72 hours, and sooner is better.
The three primary bloodborne pathogens of concern are Hepatitis B (HBV), Hepatitis C (HCV), and HIV. HBV is the most likely to be transmitted via needlestick — it can survive outside the body on dried surfaces for up to 7 days.