Infection Control & Pathogens: Medical Asepsis, Sterilization, and Healthcare Safety

Pathogen

Microorganism capable of causing disease

Host

Organism in which pathogens live and multiply

Carrier

Person who harbors pathogens without showing symptoms

Fomite

Object that can carry infectious material

Vector

Living carrier that transmits infection (e.g., mosquito)

Sepsis

Systemic infection; body's extreme response to infection

Nosocomial infection

Acquired during hospitalization

Iatrogenic infection

Infection caused by medical treatment or procedure

Direct contact

Touching infected person/body fluids

Indirect contact

Touching contaminated objects (fomites)

Droplet

Coughs, sneezes, talking (travels ~3-5 feet)

Airborne

Inhalation of evaporated droplets or dust (e.g., TB, varicella)

Vehicle

Food, water, blood, drugs

OSHA

Occupational Safety and Health Administration: sets and enforces infection control regulations.

CDC

Centers for Disease Control and Prevention: provides evidence-based infection control guidelines.

WHO

World Health Organization: coordinates international public health efforts.

The Joint Commission

Accredits healthcare institutions and enforces safety standards.

Medical Asepsis

Reduces number and spread of pathogens.

Surgical Asepsis

Eliminates all microorganisms and spores.

Disinfection

Destroys most pathogens (not spores) using methods like boiling, UV light, bleach, alcohol.

Sterilization

Destroys all microbes and spores using methods like steam under pressure (autoclave), ethylene oxide gas, chemical sterilant.

Rules of Surgical Asepsis

A sterile object remains sterile only when touched by another sterile object.

Sterile Field Contamination

If sterility is in doubt → consider contaminated.

Sterile Field Positioning

Keep sterile field above waist level and in view.

Sterile Field Contamination Zone

Outer 1 inch of sterile field is contaminated.

Sterile Person Passing

Sterile persons must pass back-to-back only.

Sterile Field Protocol

Never reach over a sterile field.

Zone 1 - Unrestricted

Street clothes permitted.

Zone 2 - Semi-restricted

Scrub dress, hair/shoe covers.

Zone 3 - Restricted

Full surgical attire + mask.

Donning PPE Order

Gown → Mask → Goggles/Face shield → Gloves

Doffing PPE Order

Gloves → Goggles → Gown → Mask

Normal Temperature Range (Adult)

97.8-99°F

Normal Temperature Range (Infant)

99-99.7°F

Normal Pulse Rate (Adult)

60-90 bpm

Normal Pulse Rate (Child)

90-100 bpm

Normal Pulse Rate (Infant)

~120 bpm

Normal Respiration Rate (Adult)

15-20/min

Normal Respiration Rate (Child)

20-30/min

Normal Respiration Rate (Infant)

30-60/min

Normal Blood Pressure (Adult)

90-120 / 50-70 mmHg

Oxygen Saturation Normal Range

95-100%

Hypoxemia Indicator

<90% indicates hypoxemia

BUN Normal Range

7-20 mg/dL

Creatinine Normal Range (Women)

0.6-1.2 mg/dL

GFR Normal Range

>90

Hemoglobin Normal Range (Women)

12-15.5 g/dL

Platelets Normal Range

150,000-450,000 /mL

PT/INR Normal Range

10-14 sec / 1.0

Neonate Development Stage

Birth-1 mo. Maintain warmth, infection prevention.

Infant Development Stage

1 mo.-1 yr. Calm tone, involve parents, security object.

Toddler Development Stage

1-3 yrs. Simple directions, allow choices.

Preschooler Development Stage

3-6 yrs. Explain in simple terms, allow independence.

School-age Development Stage

6-12 yrs. Honest answers, maintain modesty.

Adolescent Development Stage

12-19 yrs. Respect privacy, discuss pregnancy possibility with females.

Geriatrics - Three D's

Depression: sadness, hopelessness; Dementia: chronic memory and personality loss; Delirium: acute, reversible confusion.

Geriatrics Considerations

Slow processing → give time; Fall risk → monitor mobility; Sensory decline → clear, calm instructions.