Introduction

1.1. Purpose

These guidelines describe specific infection prevention and control (IPC) measures required to reduce the transmission of COVID-19.

It applies to health workers and care staff, infection control professionals, managers, support workers and other healthcare staff in settings such as:

• acute/subacute healthcare
• first responders and patient transport
• residential care facilities
• primary and community health care.

Many of the IPC principles in these guidelines can also be used in the community and in non-healthcare workplaces, particularly the:

• chain of infection
• hierarchy of controls
• cleaning
• hand hygiene
• respiratory and cough etiquette.

Note: Healthcare workers must refer to and always comply with their organisation’s policies and procedures.

Key messages

COVID-19 is predominately transmitted via inhalation of aerosols (both short- and long-range transmission is possible) particularly when an infected person is in close contact (<1.5m) with another person.

Transmission via direct contact with contaminated surfaces is possible but not common. Factors affecting transmission are:

• the concentration of viable virus shed in aerosols expelled by the infected person in the form of particles (ranging from respiratory droplets to smaller aerosols)
• the type of contact the infected person has with others, how close they are and whether the virus can enter via their mouth, nose, or eyes
• the characteristics of the setting of transmission and the infection prevention and control measures which are in place.

To reduce the transmission of COVID-19 in healthcare settings, it is essential to:

• understand standard and transmission-based precautions
• apply the hierarchy of controls
• manage routine care of suspected or confirmed cases of COVID-19 using personal protective equipment (PPE).

Variants of concern will continue to emerge. These guidelines give information for mitigating the risks of variants of differing levels of infectivity and transmissibility.

Treatment/care of patients and outpatients should not be denied or delayed because of COVID-19 IPC precautions.

1.2. Coronaviruses and COVID-19

Coronaviruses are a large family of viruses that cause illness of variable severity in humans. They include the common cold, severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

SARS-CoV-2 is the virus that causes coronavirus disease 2019 (COVID-19).

1.3. Modes of transmission

The COVID-19 virus (SARS-CoV-2) is spread by exposure to respiratory fluids carrying infectious particles. The risk of exposure to respiratory particles is highest when in close contact (within 1.5 metres where the concentration of particles is highest) with an infectious person who has respiratory symptoms, for example, coughing or sneezing.

Exposure can occur in three ways:

• Airborne transmission—very small, infectious aerosol particles can stay suspended in the air for prolonged periods of time. Inhaling aerosols is the main means of transmission of COVID-19.
• Droplet transmission—droplets containing infectious particles can be inhaled or deposited on mucous membranes (mouth, nose, or eyes).
• Indirect contact transmission—droplets with infectious particles can contaminate surfaces. Touching a contaminated surface and then touching the mouth, eyes, or nose without performing hand hygiene, can expose a person to infection. Note, however, that the risk of transmission by indirect contact is low.

1.4. Symptoms

Symptoms include cough, breathing difficulty, sore throat, runny nose, or nasal congestion with or without these other symptoms:

• headache
• myalgia
• fatigue
• diarrhoea
• nausea/vomiting

Less commonly:

• loss of appetite
• loss of smell or loss of taste
• fever (≥37.5C) or history of fever; for example, night sweats, chills.
• In the elderly, consider new or increased confusion, change in baseline behaviour, falling or exacerbation of underlying chronic illness.

All people with recent onset of new or worsening symptoms of an acute respiratory infection (ARI) should be tested for COVID-19 and managed as a possible case until COVID-19 is excluded or an alternative diagnosis is confirmed. Clinical judgement should be applied where there are alternative clinical explanations for symptoms or where non-specific symptoms are present.

1.5. Incubation and infectious period

A standardised operational definition of the infectious period for COVID-19 is used for public health activities including contact identification and management. See the department's COVID-19 (Coronavirus disease 2019) advice.

1.6. Outbreak management information

Each outbreak will differ according to the circumstances of the facility or department; therefore, the investigation and management will be applied on a case-by-case basis after identification and understanding of the features of the outbreak.

To remain prepared for COVID-19 outbreaks, each facility must have an Outbreak Management Plan.

For more information, see Management of Acute Respiratory Infection Outbreaks including COVID-19 and influenza in residential care facilities.

For more information on outbreak response procedures, see the department's COVID-19 (Coronavirus disease 2019) advice.

For further advice and guidance, see Coronavirus Disease 2019 (COVID-19) CDNA National Guidelines for Public Health Units.

1.7. Review

The information in this online publication is based on evidence and national recommendations. As new evidence or resources become available, content in this online publication may be updated. Be aware that any printed copy of this publication may become outdated and should always be compared to current information in this online publication.