2.1. The chain of infection
Transmission of infectious agents requires the following elements:
- a causative agent/pathogen (for example SARS-CoV-2)
- a reservoir
- a portal of exit
- a means of transmission
- a portal of entry
- a susceptible host.
Infection prevention and control measures aim to break one or more of the links in the chain to limit or prevent the transmission of the pathogen.
2.2. Hierarchy of controls
This is a model for managing occupational hazards in the workplace. The hierarchy ranks risk avoidance and risk mitigation strategies in decreasing order of reliability. Multiple control strategies are required to eliminate or minimise the risk of infection.
Hierarchy of controls
Hierarchy of controls
A diagram ranking health and safety control measures from the highest, most reliable level of protection to the lowest, least reliable level.
From highest to lowest protection, the measures are:
- Eliminate risks.
- Substitute the hazard with a safer alternative; isolate the hazard from people; reduce the risks through engineering control.
- Reduce exposure to the hazard using administrative controls.
- Use personal protective equipment.
2.3. Strategies to reduce COVID-19 transmission
COVID-19 infection prevention and control strategies should be aligned to the hierarchy of controls approach to risk.
Table 1. Hierarchy of controls and infection control strategies
|Hierarchy of controls||Example IPC strategies|
Removal of the virus from the workplace and therefore eliminate the risk of transmission.
Elimination of the COVID-19 virus itself is unlikely.
Exclude unwell staff from the workplace
Offer alternative work options for at-risk staff
Screen staff and visitors prior to entry to the workplace
Use telehealth to minimise face-to-face consultations
Finding other ways to provide care that reduce potential for transmission.
Use telehealth in place of face-to-face consultations.
Consider conducting activities outdoors.
Isolation of infected persons to prevent potential transmission.
Use Class N negative pressure rooms for COVID-19 positive patients. If not available, use standard isolation rooms or single rooms with private bathrooms.
Use of patient zones.
Changes to infrastructure or equipment or change systems of work.
Optimise ventilation systems/zones in buildings.
Use air cleaning devices.
Consider the use of clear perspex screens (with caution).
Implementation of policies and protocols to guide practices that reduce risk.
Implement policies such as:
Personal protective equipment
Worn to protect the wearer from infection.
Use transmission-based precautions.
Use PPE (masks, respirators, gowns, gloves, and eye protection).
Reviewed 25 May 2023