Standard Precautions & Infection Control – Adelaide Nursing School Lecture

Learning Outcomes

• Define and describe standard precautions.

• Explain transmission‐based (additional) precautions.

• Compare different methods of hand hygiene.

• Understand equipment re-processing: cleaning, disinfection, sterilisation.

• Relate all of the above to breaking the Chain of Infection.

Microbial Transmission & Chain of Infection

• Principal routes of microbial spread

  • Contact

  • Direct (person-to-person).

  • Indirect (via objects/fomites).

  • Droplet (large particles, fall within ≈1 m).

  • Airborne (≤5 µm nuclei, remain suspended & travel long distances).

  • Vehicle-borne – contaminated water, food, blood, IV fluids.

  • Vector-borne – insects/animals carrying organisms between hosts.

• Classic Chain of Infection (cyclical):

  • Susceptible host ⇄ Source/Reservoir ⇄ Mode of transmission.

  • Interruption of ANY link prevents infection.

Nosocomial (Hospital-Acquired) Infections

• Definition: Infection whose development is favoured by the hospital environment; affects in-patients and staff.

• Contributing factors

  • Depressed or immature immunity (illness, chemotherapy, steroids, radiation; neonates; elderly).

  • Comorbidities – diabetes, PVD, cardiac disease, COPD, smoking, etc.

  • Virulence & resistance of the agent (e.g., VRE, MRSA).

  • Situational/iatrogenic: surgery, urinary catheter, IV line, other indwelling devices = direct portal of entry.

  • “Cluster effect” – many sick people in close proximity, harder to isolate.

Common Causative Organisms

• Staphylococcus aureus (inc. MRSA)

• Candida spp. (yeasts)

• Pseudomonas spp.

• Acinetobacter spp.

• Vancomycin-Resistant Enterococci (VRE)

Epidemiology & Key Statistics

• Data ~10 years old; current trends similar (<$1\%$ change).

• MOST COMMON nosocomial infection: Urinary Tract Infection – aligns with catheter use.

• Rank order (US):

  1. UTI

  2. Surgical-site infection (SSI)

  3. Blood-stream infection & Pneumonia (tie; pneumonia ↓ markedly).

• France (same era):

  • UTI & skin/mucous infections ≈ $10\%$ each.

  • SSIs ≈ $12\%$ (previously $14.2\%$).

• UK (2006): overall HA-infection rate $\approx10\%$ (estimate $8.2\%$).

• Australia (2006): overall HA-infection rate $8.4\%$ → ≈$7000$ deaths/yr.

• Ethical & practical implication: each % drop saves hundreds of lives; nursing practices have measurable impact.

Elements of Standard Precautions

• Hand hygiene (central pillar)

• Personal Protective Equipment (PPE)

• Environmental & equipment cleaning

• Clinical waste management

• Linen management

• Spill management

• Sharps injury prevention

• Isolation precautions (room, signage, dedicated equipment)

• Respiratory / cough etiquette

Rationale for Universal Application

• Patients may be:

  • Asymptomatic carriers.

  • In window period (contagious before symptoms).

  • Awaiting lab identification (result delay).

• Protects BOTH patients & healthcare workers – default minimum IPC standard.

Hand Hygiene

• “Single most important” infection-control procedure; professional responsibility.

• Methods

  • Alcohol-based rub/gel – bedside, quick, “five moments”.

  • Soap & water (bar or liquid) – when visibly soiled / after body-fluid exposure / routine “prophylactic” wash (start of shift, post-meal, etc.).

• The 5 Moments (WHO):

  1. Before touching a patient

  2. Before a procedure

  3. After procedure/body-fluid exposure risk

  4. After touching a patient

  5. After touching patient surroundings

• Additional obligatory times: post-toilet, after food handling, between patients, after coughing/sneezing, after glove/PPE removal, start & end of work.

• Technique standards

  • Handwash: 11 steps; cover all surfaces; 40–60 s.

  • Handrub: 8 steps; 20–30 s; ensure dry.

• Efficacy evidence: Agar-plate imprint shows dramatic reduction in flora after alcohol rub – confirms germ-killing capacity.

Personal Protective Equipment (PPE)

• Use when contact with blood, body fluids, non-intact skin or mucous membranes anticipated.

• Components

  • Gloves (single-use).

  • Gown/Apron – fluid resistant.

  • Protective eyewear (goggles/face shield).

  • Masks:

  • Surgical mask

  • N95 ("N" = not oil-resistant; "95" = ≥$95\%$ filter efficiency for 0.3 µm particles).

  • Surgical mask + integrated eye shield.

• Donning (typical sequence)

  1. Hand hygiene

  2. Gown

  3. Mask/Respirator

  4. Goggles/face shield

  5. Gloves (last, over gown cuffs)

• Doffing (reverse mindset – avoid self-contamination)

  1. Gloves

  2. Hand hygiene

  3. Goggles/face shield

  4. Gown

  5. Mask/Respirator

  6. Hand hygiene again

• Training resources: Adelaide Health & Simulation Centre videos for donning/doffing.

Environmental Cleaning & Equipment Re-processing

• Goal: reduce environmental bioburden; microbes survive prolonged periods on dry surfaces.

• Staff assist by decluttering & clearing horizontal surfaces before cleaning.

• Item classification (Spaulding):

  • Non-critical – contact intact skin (e.g., BP cuff, SpO₂ probe, stethoscope); clean w/ low–intermediate level disinfectant after every use.

  • Semi-critical – contact mucous membranes/broken skin; require high-level disinfection or sterilisation.

  • Critical – enter sterile body sites/vascular system; must be sterile.

Spill Management

• Spills vary (blood, body fluids, chemicals) → need correct agent & PPE.

• Standardised Spill Response Kits on wards:

  • Clear instructions sheet for each spill type.

  • Orientation includes knowing kit location.

Sharps Injury Prevention

• Major hazard: forcing sharps into over-full containers.

• Controls: single-entry sharps bins, fill-line indicators, immediate disposal at point of use.

• Follow organisational post-exposure protocol if injury occurs.

Additional (Transmission-Based) Precautions

• Terminology: formerly “transmission-based”; universal → standard now preferred.

• Categories (ADDED to standard precautions):

  • Contact – MRSA, VRE, resistant GNRs.

  • Droplet – pertussis, influenza, meningococcal meningitis, some pneumonias.

  • Airborne – tuberculosis, varicella, measles.

• Implementation determinants: organism identity + route of spread.

• Common elements across categories

  • Door signage (ACSQHC-endorsed) instructing visitors to see nurse.

  • PPE supply outside room.

  • Ideally single room + dedicated toilet.

  • Allocate immune staff where relevant (e.g., immune nurse for chickenpox case).

  • Patient-specific equipment; surgical/N95 mask during transport.

  • Enhanced cleaning using disinfectant active against the known pathogen.

  • May require “specialling” if patient acuity demands rapid response.

Airborne Precautions (Add-on)

• N95/P2 respirator before entry; fit-checked.

• Negative-pressure room if available.

Droplet Precautions (Add-on)

• Surgical mask before entry; dispose on exit.

Contact Precautions (Add-on)

• Gown + gloves before entry; remove & perform hand hygiene before exit.

Cough Etiquette / Respiratory Hygiene

• CDC & WHO “Cover Your Cough” campaigns adopted in Australia.

• Best practice

  • Cover mouth & nose with tissue → bin immediately → hand hygiene.

  • If no tissue, cough/sneeze into elbow/upper sleeve (NOT hands).

  • Wash hands with soap & running water; dry thoroughly.

• Low population immunity to some droplet/airborne agents means public education is vital.

Integration, Clinical Significance & Ethical Considerations

• Each link in infection control chain (hand hygiene, PPE, cleaning, isolation) supports the others; failure of one jeopardises the whole system.

• Evidence-based reductions of even $1\%$ infection incidence equate to hundreds of lives saved and massive cost avoidance.

• Maintaining diligence upholds professional ethics (duty of care) and legal obligations (workplace health & safety).

• Continuous auditing, education, and culture of safety are essential for sustained compliance.

“Everybody knows that washing your hands is the best way to stop germ transmission – it’s your responsibility.”