Infection Control

Infection control consists of policy and protective equipment designed to:

Standard/Universal Precautions

Steps taken with all patients, irrespective of suspected or confirmed disease:

  • Hand hygiene
  • Use of appropriate PPE during procedures
  • Safe disposal of sharps
  • Aseptic, no-touch procedure technique
  • Environmental cleaning and laundry
  • Cough etiquette

Contact Precautions

For pathogens spread by direct patient contact, or indirectly by contact with patient environment. Includes:

Examples include:

  • Diarrhoea
  • Meningitis
    In children for suspected enteroviruses, or for confirmed M. tuberculosis.
  • Exotic viruses
    Ebola, etc.
  • Pneumonias
    S. Aureus, S. Pneumoniae, M. tuberculosis.
  • MRSA
  • Single room
    • Patients with the same disease can be co-located, but should be separated by >1m
      Standard precautions apply between patients in the room.
  • PPE
    • Gloves for contact with skin
    • Gown if clothes will contact environment
  • Minimise movement of patient outside room
  • Disposable equipment
  • Daily cleaning and disinfection

Droplet Precautions

For pathogens spread by close respiratory or mucous membrane contact, but that do not cover long distances in air. Includes:

Examples include:

  • B. pertussis
  • Influenza virus
  • Adenovirus
  • Rhinovirus
  • N. meningitides
  • As contact precautions
  • Single room
    • If unavailable, patient should be cohorted with their current roommate to prevent additional exposures
    • Draw curtains in multi-bed room
  • Standard mask

Airborne Precautions

For pathogens that remain infectious over long distances in air. Includes:

The distinction between pathogens spread by droplets and those spread by air depends on particle size, with larger suspensions traveling shorter distances and falling more quickly. The somewhat arbitrary cut-off is ~5µm, from which is derived the 1-2m social distancing rules we are too-familiar with.

Examples include:

  • M. Tuberculosis
  • VZV
  • HSV
  • Measles
  • S. Aureus Pneumonias
  • COVID-19
  • As contact precautions
  • Isolation room
    • Single room
    • 12 air changes per hour
      Via HEPA filter, or to outside.
  • N95 mask or PAPR
  • Susceptible staff should not enter the room
    • e.g. Pregnant, immunocompromised, etc.
    • Vaccinated staff should care for patients with vaccine-preventable disease

If contact occurs outside of a positive-pressure room, then:

  • Mask the patient
  • Keep the patient in a private room with the door closed
  • Use N95 mask for staff

Protective Environment/Reverse Precautions

Reverse precautions are used for severely immunocompromised patients to protect them from staff and visitors, and to ↓ fungal spore counts in the air. Includes:

  • Airborne precautions for staff and visitors
  • Positive-pressure isolation room
    • Anteroom
    • Pressurised relative to surrounding rooms/environment
    • HEPA filtration of incoming air with ⩾12 changes/hour
    • Dust-minimisation design and cleaning
    • Air flow directed towards entry point of the room
  • No flowers or plants

Discontinuation of Precautions

Cessation of precautions varies with the disease, and is usually based on either:

  • Time of treatment
  • Evidence of resolution

References

  1. Bersten, A. D., & Handy, J. M. (2018). Oh’s Intensive Care Manual. Elsevier Gezondheidszorg.
  2. CDC. Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings. 2007.
  3. Randall K, Ewing ET, Marr LC, Jimenez JL, Bourouiba L. How did we get here: what are droplets and aerosols and how far do they go? A historical perspective on the transmission of respiratory infectious diseases. Interface Focus. 2021 Oct 12;11(6):20210049.