5.1 Infection Control, Standard Precautions & Bloodborne Pathogens

Infection Control, Standard Precautions & Bloodborne Pathogens

Infection control is a fundamental clinical requirement in phlebotomy. Phlebotomists interact directly with diverse patients and handle blood and body fluids daily. Understanding pathogen transmission, personal protective equipment (PPE), regulatory standards, and post-exposure protocols protects patients and healthcare workers alike.

The Chain of Infection

Disease transmission requires six interconnected links in an unbroken chain. Interrupting any single link halts the transmission cycle.

1. Infectious Agent (Pathogen): Biological micro-organisms causing disease, including bacteria (S. aureus, C. difficile), viruses (HBV, HCV, HIV, Influenza), fungi, and parasites.
2. Reservoir: The habitat where pathogens live and multiply, including infected patients, personnel, contaminated water, dirty phlebotomy trays, and countertops (fomites).
3. Portal of Exit: The pathway by which pathogens leave the reservoir, such as blood, respiratory droplets, saliva, exudates, and excretions.
4. Mode of Transmission: The mechanism of movement from reservoir to host:
   • Direct Contact: Physical touch between infected individual and susceptible host.
   • Indirect Contact: Touch contact with contaminated inanimate objects (fomites) like dirty blood tube holders.
   • Droplet Transmission: Inhalation of large infectious droplets (>5 microns) generated by coughing or sneezing within 3 to 6 feet.
   • Airborne Transmission: Inhalation of microscopic droplet nuclei (<5 microns) suspended in the air over long distances.
5. Portal of Entry: The site through which pathogens enter a host, primarily percutaneous needlesticks, skin abrasions, or mucous membrane splashes.
6. Susceptible Host: Individuals lacking effective immunity, such as elderly, immunocompromised, or surgical patients.

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Standard Precautions vs. Transmission-Based Precautions

Standard Precautions (Tier 1)

Standard Precautions apply to all patients in all healthcare settings, regardless of infection status. All human blood, body fluids, secretions, excretions (except sweat), non-intact skin, and mucous membranes are treated as potentially infectious.

Key practices include:

• Hand Hygiene: Wash with soap and water or alcohol-based hand rub before and after patient contact, after glove removal, and after touching surfaces.
• PPE Use: Wear clean gloves for blood or fluid contact. Add gowns, masks, or eye protection if splashing is anticipated.
• Safe Sharps Disposal: Use safety-engineered devices and dispose of needles immediately into puncture-resistant containers.

Transmission-Based Precautions (Tier 2)

Implemented in addition to Standard Precautions for suspected or confirmed contagious pathogens.

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PPE Donning & Doffing Sequences

Donning Sequence (Putting On)

1. Gown: Cover torso from neck to knees and arms to wrists; fasten at neck and waist.
2. Mask/Respirator: Secure ties or elastic bands at head and neck; fit noseband snugly.
3. Goggles/Face Shield: Place over face and eyes; adjust fit.
4. Gloves: Extend gloves to cover gown cuffs.

Doffing Sequence (Taking Off)

1. Gloves: Remove gloves first (most contaminated). Use glove-to-glove, skin-to-skin technique.
2. Goggles/Face Shield: Remove from back by handling clean headband/ear pieces.
3. Gown: Unfasten ties, peel gown away from shoulders touching inside only, roll inside out into bundle.
4. Mask/Respirator: Grasp bottom ties then top ties; remove without touching front. (Doff N95 outside room).
5. Hand Hygiene: Perform hand hygiene immediately after removing all PPE.

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OSHA Bloodborne Pathogens Standard (29 CFR 1910.1030)

Designed to protect workers from occupational exposure to Hepatitis B Virus (HBV), Hepatitis C Virus (HCV), and Human Immunodeficiency Virus (HIV).

Key mandates:

• Exposure Control Plan (ECP): Written, site-specific plan reviewed and updated annually.
• Hepatitis B Vaccine: Offered free of charge within 10 working days of initial assignment.
• Universal Precautions: Treat all human blood and specified body fluids as infectious.
• Work Practice Controls: Prohibit eating, drinking, smoking, or applying cosmetics in blood-handling areas.

Post-Exposure Prophylaxis (PEP) Protocol

[1. Immediate First Aid] ---> [2. Report Exposure] ---> [3. Baseline Testing] ---> [4. Initiate PEP (<2 hrs)]
 (Wash site with soap/water;    (Notify supervisor       (Draw employee &       (Begin antiretrovirals
  flush eyes 15 min)             immediately)             source bloods)         for HIV exposure)

1. Immediate First Aid: Wash needlestick wounds with soap and running water for several minutes. Do NOT squeeze or milk the wound. Flush splashes to eyes or mouth with saline or water for 15 minutes.
2. Immediate Reporting: Report incident immediately to supervisor and occupational health.
3. Medical Evaluation: Obtain consent to test employee and source patient for HBV, HCV, and HIV.
4. PEP Timing: Initiate HIV Post-Exposure Prophylaxis antiretrovirals as soon as possible, ideally within 2 hours (and under 72 hours), continuing for 28 days.

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Needlestick Safety and Prevention Act

Enacted in 2000, this law revised the OSHA BBP Standard to mandate safer needle engineering controls.

• Sharps Safety Devices: Requires built-in safety features (e.g., hinged needle shields, retractable lancets).
• Sharps Injury Log: Employers must maintain a confidential log recording device type, location, and incident details.
• Frontline Employee Input: Non-managerial phlebotomists must participate in evaluating safety devices annually.
• Sharps Disposal Rules: Activate safety device immediately after draw and dispose into rigid, puncture-resistant biohazard containers. Never recap, bend, break, or manually remove needles.

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Clinical Scenario: Post-Exposure Needlestick Management

A phlebotomist completes a venipuncture in the emergency room. While attempting to shield the needle, the patient moves suddenly, causing a needle puncture to the phlebotomist's index finger. The phlebotomist immediately activates the safety shield, disposes of the needle into the sharps container, and washes the wound at the sink with soap and water for 5 minutes without squeezing. The phlebotomist notifies the charge nurse and supervisor. Baseline blood samples are collected from both the phlebotomist and source patient following consent. The employee health physician prescribes HIV PEP antiretrovirals, which the phlebotomist begins within 75 minutes of the exposure.

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Common Exam Traps

Exam Trap 1: Gloves are doffed first during PPE removal because they are most contaminated. Masks/respirators are doffed last.

Exam Trap 2: For C. difficile contact precautions, alcohol hand rubs are ineffective. You must wash with soap and running water to remove spores.

Exam Trap 3: Never squeeze or milk a needlestick wound, as this causes tissue micro-trauma and draws pathogens deeper into capillaries.

Exam Trap 4: Employers must offer the Hepatitis B vaccine at no cost within 10 working days of initial assignment.