WA COVID-19 Testing Guidelines - State Health Incident Coordination Centre (SHICC) Department of Health, WA

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WA COVID-19 Testing Guidelines - State Health Incident Coordination Centre (SHICC) Department of Health, WA
WA COVID-19 Testing
Guidelines
State Health Incident Coordination Centre (SHICC)
Department of Health, WA

Version 3.0
09 January 2022
Version Control and Approval
This document should be considered a ‘live document’ and will be reviewed and updated regularly in
response to:
   •   New legislation or statutory directions;
   •   Changes in advice based on emerging evidence or national guidelines;
   •   Learnings from outbreak management locally, in other jurisdictions and internationally; or
   •   Stakeholder engagement and feedback.

Review and update of this document is coordinated by the State Health Incident Coordination Centre
(SHICC) Planning Cell which can be contacted with feedback at PHEOC@health.wa.gov.au.

 Version    Date            Author       Approved by               Comments on revision
 1.0        03 December     SHICC        Dr Paul Armstrong         Original version
            2021            Planning     Deputy Chief Health
                            Cell         Officer
 2.0        04 January      SHICC        Dr Paul Armstrong         Stakeholder feedback
            2022            Planning     Deputy Chief Health       Table updated
                            Cell         Officer                   Hospital ED testing aligned to
                                                                   HSP framework for respiratory
                                                                   pathways
                                                                   Omicron variant information
                                                                   included

 3.0        09 January      SHICC        Dr Revle Bangor-          WA Health System Alert Levels
            2022            Planning     Jones                     Red and Black completed in table
                            Cell         A/Deputy Chief Health     Table aligned to national policy
                                         Officer                   Removal of Outbreak testing
                                                                   Appendix C updated

                                                                                                    2
Contents
 Introduction......................................................................................................................................... 4
    Objectives ...................................................................................................................................................................... 5
    Out of Scope ................................................................................................................................................................. 5
 Priority Groups for Testing ............................................................................................................... 5
 Surveillance activities ........................................................................................................................ 6
    Wastewater testing....................................................................................................................................................... 6
    Whole genome sequencing ........................................................................................................................................ 6
 Funding Considerations .................................................................................................................... 6
 Legislative Considerations ............................................................................................................... 7
 Omicron ............................................................................................................................................... 7
    TTIQ ............................................................................................................................................................................... 7
 WA COVID-19 Testing Framework ................................................................................................... 8
 COVID-19 Testing Matrix ................................................................................................................... 9
    Symptomatic Testing ................................................................................................................................................... 9
    Asymptomatic Testing - Borders ................................................................................. Error! Bookmark not defined.
    Asymptomatic Testing – Hospitals (Staff) ............................................................................................................... 10
    Asymptomatic Testing – Non-Hospital health settings ......................................................................................... 14
    Asymptomatic Testing – Specific settings ................................................................. Error! Bookmark not defined.
 APPENDIX A: SARS-CoV-2 specific testing, Australia .................................................................16
 APPENDIX B: Rapid Antigen Testing (RAT) ..................................................................................17
 APPENDIX C: Current Directions for Testing ................................................................................19
 Works Cited........................................................................................................................................21

                                                                                                                                                                                    3
Introduction
It should be noted that these guidelines will be subject to frequent revision in response
to changing epidemiology, emerging evidence, stakeholder feedback and experiential
learning of effectiveness and logistical challenges.

On 30 July 2021, the National Plan to Transition Australia’s COVID-19 Response was
announced, which outlined federal plans for the opening of Australia’s interstate and
international borders. Western Australia’s (WA’s) Safe Transition Plan for easing border
controls once a 90% double dose vaccination rate is achieved was announced on 5 November
2021. The date for the easing of Western Australia’s border controls has been set for February
5th, 2022.

The goal for the management of COVID-19 in Western Australia will transition from elimination
to suppression of community transmission to a level that does not overwhelm health services.
Test, trace, isolate and quarantine (TTIQ) practices will be an important part of the public health
response to slow COVID-19 transmission, minimise serious illness, hospitalisation and death
and ensure health system capacity. Slowing community transmission will allow time to achieve
good vaccination coverage in the 5-11-year-old cohort, third dose vaccination for those eligible
and maintain delivery of usual health services.

High levels of polymerase chain reaction (PCR) testing and maintenance of rapid turnaround
times for results, will be important to ensure case detection of COVID-19 and efficient contact
tracing to contain an outbreak [1]. Maintenance of high PCR testing rates for symptomatic
individuals is key to early detection of outbreaks during the transition phase; noting that the
pressure on testing capacity will require the use of alternative testing methods, such as rapid
antigen testing, at a certain level of community transmission and in specific settings [1].

Established community transmission and maximum utilisation of laboratory PCR testing
capacity will lead to wider use of rapid antigen tests (RATs) to complement, but not replace,
the PCR test as the gold standard test for diagnosis of SARS CoV-2 infection [2]. Where there
is little or no community transmission of COVID-19, screening for the virus using RAT in low-
risk settings (including workplaces) has limited benefit [3]. In these situations, it would be more
beneficial for employers to encourage workers to apply COVIDSafe work practices, ensure
high vaccination coverage, and for employees and their close contacts to get tested via PCR
and isolate if symptoms develop [3].

In an environment with little or no community transmission, any non-negative RAT result must
be followed up by a PCR test with the person isolating until the PCR result is known.

RATs could be used as a screening test in occupational settings that have a potential for
greater exposure to the SARS CoV-2 virus (such as quarantine workers, health care setting
and border workers) with increased frequency of RAT testing improving sensitivity. Further
information on the advantages and limitations of RAT is provided in Appendix B.

The areas of testing this guideline will address which require state-level strategic planning
are:
   1. Symptomatic testing for self-presenting individuals

                                                                                                4
2. Asymptomatic testing for screening

Objectives
This paper will:
   1. Outline PCR testing prioritisation and use after border restrictions in WA are relaxed.
   2. Determine the role of rapid antigen testing (RAT) for screening.
   3. Provide guidance for the use of RAT in WA, including in high-risk settings and
      workplaces.
   4. Inform legislative changes to support the testing guidelines.

Out of Scope
Out of scope for this paper includes:
   • Wastewater surveillance, which is governed by a separate steering committee.
   • Emerging technologies such as extraction-free loop-mediated isothermal amplification
       (LAMP)

Priority Groups for Testing
The national framework [5] identified four priority groups for targeted testing in Australia:

  1. People with COVID-19 compatible symptoms

  2. People with known recent exposure to SARS-CoV-2
     a) Household – secondary attack rate, can be close to 100% in some Australian
        households [1]
     b) Other contacts

  3. People at higher risk of exposure to SARS-CoV-2
     a) International or domestic travellers
     b) Health care workers with direct patient contact
     c) Aged and disability care workers with direct patient contact
     d) Border staff
     e) Quarantine centre workers
     f) Workers transporting persons arriving to WA via air or sea
     g) Aircrew
     h) Maritime crew

  4. People in high risk settings where disease amplification is likely, or where people live or
      visit who are at increased risk of severe disease. For example:
     a) High population density settings
     b) People living or working in proximity to others e.g. Congregate living
     c) Specific environmental conditions
     d) Remote Aboriginal and Torres Strait Islander communities
     e) Secure facilities (correctional and detention facilities)
     f) Mining and Offshore sites

                                                                                                5
g) Food processing, distribution, and cold storage facilities, including abattoirs –
          (Industrial facilities)
       h) Residential aged care facilities
       i) Hospitals
       j) Schools and childcare facilities

The testing approach used in WA must be adaptable and responsive to the introduction of
community transmission when border restrictions are relaxed and must strike the right balance
between limiting community transmission through case finding and controlling outbreaks, and
protecting the sustainability of laboratory and testing site capacity [5].

Surveillance activities
Wastewater testing
The WA Department of Health led SARS-CoV-2 Wastewater Surveillance Program
commenced on 17 September 2020, with the aim of providing information about the existence
of COVID-19 disease (active or recovered) within the WA community, by detecting non-
infectious genetic material shed by cases or recovering cases, in order to complement existing
and future clinical COVID-19 surveillance activities.

Whole genome sequencing
Whole genome sequencing (WGS) is used to compare the genomic relatedness from multiple
COVID-19 cases to facilitate investigations by public health units. It has also allowed mutational
analysis for Variants of Concern (VoC) [6]. While a comprehensive WGS strategy of
sequencing all suitable SARS-CoV-2 positive clinical specimens is possible in a low prevalence
setting, this will not occur when case numbers rise and a change in genomic surveillance to
selective and targeted sequencing will be required.

With the recommencing of international travel the potential for importation of new VoC will
increase. Indeed, this has been highlighted in the recent detection of the Omicron variant:
B.1.1.529 detected in Southern Africa.

Where there is an accepted level of community transmission, it will not be necessary to
sequence all samples where COVID-19 has been acquired in Australia, but a testing approach
will be required to ensure detection of new variants with increased transmissibility/virulence
and vaccine escape occurs in a timely manner. Considerations for targeting sequencing for
cases include:
     • Sampling all positive cases acquired overseas
     • Sampling one or two cases from identified clusters
     • Sentinel surveillance through community-based surveillance, including samples from
       those who are fully or partially vaccinated
     • Sampling of hospitalised cases [1].

Funding Considerations
   •     PCR testing for COVID-19 that is mandated under a Public Health Order or Emergency
         Management Act Order is funded under the National Partnership on COVID-19
         response. This is a 50:50 cost shared arrangement between the Commonwealth
         Government and jurisdictions.

                                                                                              6
•   The funding for rapid antigen testing in residential aged care facilities is the responsibility
       of the Commonwealth Government.
   •   Any testing that has been requested or arranged from the Public Health team as part of
       a COVID-19 outbreak response is the responsibility of the WA government.
   •   Any surveillance testing in a workplace performed outside of a public health outbreak
       response, will be the responsibility of the workplace or organisation.

Legislative Considerations
A comprehensive list of all current Directions related to testing are contained in Appendix C.
This includes Directions and Chief Health Officer (CHO) approvals for testing made under the
Emergency Management Act 2005 (WA) and the Public Health Act 2016 (WA). Any changes
to COVID-19 testing arrangements will affect these instruments.

Omicron
The Omicron variant has become the dominant strain of COVID-19 in Australia. Evidence of
the intrinsic transmissibility of this variant, disease severity and the effectiveness of current
vaccines and treatments against transmission is emerging.

Early evidence indicates that Omicron is substantially more transmissible than the Delta variant
in populations with a high previous exposure to COVID-19 and/or high vaccination coverage,
with most recent estimates demonstrating that the number of cases doubles every 2-3 days
[7]. Secondary COVID-19 infection rates in household contacts of Omicron cases in the United
Kingdom appear higher than those for Delta (13.6% versus 10.1% respectively) [8] and more
transmission occurs to contacts of Omicron than those of Delta cases.

Preliminary findings in the United Kingdom also suggest up to a 40-45% reduction in the risk
of hospital admissions for Omicron relative to Delta infections [9] and a reduction in emergency
department attendance [8]. However, relative to Delta, Omicron infections in the United
Kingdom are currently more concentrated in the young adult age group (20-29) and this should
be kept in mind in comparison analyses.

Even at the reduced hospitalisation rates observed compared to previous variants, the
increased transmissibility of Omicron has the potential to put pressure on the health system
due to the potential to infect more people leading to high numbers of hospital admissions.
Health system capacity will be further impacted by staff being furloughed due to being
diagnosed with COVID-19 or being identified as a close contact.

TTIQ
While TTIQ has been demonstrated to be effective, it is limited by operational factors and the
community’s      willingness     to   be   tested    and     comply      with     public  health
recommendations. Therefore, the overall contribution of TTIQ to limiting transmission will
decrease with higher case numbers. This may lead to a requirement in the future to rely more
heavily on other control methods such as indoor mask wearing and strategic use of rapid
antigen testing, to control transmission and impacts, particularly in high-risk settings.

In the context of community transmission specific strategies will be needed to protect high risk
settings and those who work or visit these. This may include expanding the use of rapid antigen
testing in settings such as aged care facilities, clear messaging to individuals at higher risk of

                                                                                                  7
severe disease to ensure they are fully vaccinated and have accessed a booster dose and
ensuring timely access to therapeutics.

WA COVID-19 Testing Framework
The framework below uses the epidemiological contexts described as “Epidemiological Zones”
in the CDNA publication Revised Testing Framework for COVID-19 in Australia (in press). For
ease of use these Epidemiological Zones have been renamed phases in the matrix below.
There may be more than one Epidemiological Zone or phase occurring at the same time within
WA. This will require different, regional approaches to testing in addition to consideration of
local vaccination rates.

When COVID-19 is introduced into WA, enhanced testing responses to localised outbreaks will
be proportionate to local epidemiological factors and may be limited to local areas. The
emergence of the Omicron variant as the dominant strain in some jurisdictions has shown a
rapid increase in cases compared to previous variants, with testing and health system capacity
being reached earlier than modelling projections. In WA a relatively short timeframe (weeks
rather than months) should be prepared for before testing or tracing capacity is reached.

An additional category may be considered later to represent a new ‘business as usual’ once
WA passes the expected wave of cases when border restrictions cease. The CDNA
Epidemiological Zones are defined as:

Epidemiological Zone 1     No locally acquired cases outside of returned travellers in
                           quarantine. No community transmission. Current WA position as
                           of 26 November 2021 prior to border relaxation.

Epidemiological Zone 2     Sporadic cases and clusters, through to wide-spread community
                           transmission, with laboratory testing and public health capacity
                           meeting testing demand.

Epidemiological Zone 3     Wide-spread community transmission, with testing demand
                           exceeding laboratory and public health capacity.

Please note that the epidemiological zones described above may vary as the epidemiological
context in WA evolves.

                                                                                           8
COVID-19 Testing Matrix
Phase                                     Phase 1                                      Phase 2                                     Phase 3
CDNA Zones                Epidemiological Zone 1 (current)             Epidemiological Zone 2                      Epidemiological Zone 3
                          No local transmission                        Clusters and community transmission         Widespread transmission exceeding
                                                                                                                   testing and public health capacity
Triggers                  Current conditions                           Once there is sustained community           Rate of transmission exceeds:
                                                                       transmission, manageable within existing        i.   health system capacity;
                                                                       health services and resources.                 ii.   testing capacity; or
                                                                                                                     iii.   the ability to perform detailed
                                                                                                                            contract tracing activities.
  WA Health System               Green: COVID-19 READY                       Amber: COVID-19 ALERT                  Red: Widespread           Black: SYSTEM
      Alert Level           Disease contained, nil to very limited     Disease in community but still contained         transmission           AT CAPACITY
  (current definitions)       numbers increasing in community                                                             Community          Service demand
                          Satisfactory vaccination rates and testing                                                   transmission of       exceeds service
                                          capacity                                                                      COVID-19 no          capacity
                                                                                                                     longer contained

Symptomatic Testing

Symptomatic               All to be tested with nose and throat PCR    All to be tested with nose and throat PCR   RAT as soon as possible.
individuals                                                            until testing capacity is reached then      If negative, repeat RAT in 24 hours.
                          Particularly important to test patients      consider rapid antigen test (RAT) for
*PCR should be            presenting to hospital with pneumonia or     diagnostic purposes.                        Positive RAT should be considered
encouraged as the         acute respiratory infection [5]                                                          confirmed COVID-19 case.
appropriate test for
symptomatic people.

                                                                                                                              9
Asymptomatic Testing – Hospitals (Staff)
  WA Health System                Green: COVID-19 READY                        Amber: COVID-19 ALERT                 Red: Widespread          Black: SYSTEM
      Alert Level            Disease contained, nil to very limited      Disease in community but still contained       transmission          AT CAPACITY
  (current definitions)        numbers increasing in community                                                            Community           Service demand
                           Satisfactory vaccination rates and testing                                                  transmission of        exceeds service
                                           capacity                                                                     COVID-19 no               capacity
                                                                                                                      longer contained
Hospitals (Public and
Private sector) staff      Voluntary nose and throat PCR test on Voluntary twice weekly RAT with a No testing required.
                           day 5 and 12 after first contact with a minimal interval 72 hours apart
Areas within a hospital    COVID-19 patient and then every 7 days
 • Intensive care unit     until 14 days pass from last contact.
 • High dependency
                           If an HCW who has had contact with a          Any breach of infection control practices
     unit
                           positive COVID-19 patient is involved in a    or personal protection equipment should
 • Respiratory wards       breach of infection control practices or
 • Emergency                                                             be managed by the health service
                           personal protection equipment, then           infection control team
     departments           Public Health advice is sought to decide if
 • A COVID clinic          any additional COVID-19 testing in
 • Other units at the      addition to the above is required.
     discretion of the
     hospital operator
Hospitals (Public and
Private sector) staff                                                    Twice weekly RAT with a minimal interval    Daily RAT for all staff if feasible – but
    • Healthcare                                                         72 hours apart                              consideration may be given to limiting to
        settings                                                                                                     symptomatic staff only.
        managing very
                                                                                                                     RAT for visitors at each visit
        high-risk
        patients (e.g.
                                                                                                                     Note: This regime is subject to
        transplant ward,
                                                                                                                     consideration of community prevalence
        haematology
                                                                                                                     and availability of RAT kits.
        unit, oncology

                                                                                                                                10
ward, renal
       dialysis unit)

Asymptomatic Testing – Hospitals (Patients/Visitors)

  WA Health System               Green: COVID-19 READY                       Amber: COVID-19 ALERT                       Red: Widespread        Black: SYSTEM
      Alert Level           Disease contained, nil to very limited     Disease in community but still contained             transmission        AT CAPACITY
  (current definitions)       numbers increasing in community                                                                 Community         Service demand
                          Satisfactory vaccination rates and testing                                                       transmission of      exceeds service
                                          capacity                                                                          COVID-19 no             capacity
                                                                                                                          longer contained
Hospitals (Public and                                                  Recommend triaging patients presenting           If supplies of RAT adequate, test all
Private sector) –                                                      to emergency departments according to            patients presenting to emergency
unplanned patient                                                      the reasons for attending as per the             departments with RAT to assist with
presentations                                                          EMHS proposed respiratory pathways in            patient management.
                                                                       Emergency Departments in WA Health
   a) Hospital                                                                                                          If RAT limited, then
      emergency                                                        Group 1: Confirmed COVID-19 case. No
                                                                                                                           •   All patients to be managed as
      departments                                                      further COVID-19 testing required
                                                                                                                               probable COVID
                                                                       Group 2: Suspect COVID-19 infection.                •   If symptoms consistent with
                                                                                                                               COVID-19 then for RAT
                                                                         i.       Patient has clinical and/or
                                                                                  epidemiological criteria consistent   Positive RAT should be considered
                                                                                  with the case definition for          confirmed COVID-19 case.
                                                                                  COVID-19.
                                                                              •   RAT testing on arrival +/- PCR
                                                                                  test

                                                                        ii.       Patients unable to use PPE
                                                                                  effectively e.g. agitated patients,

                                                                                                                                   11
patients with dementia, paediatric
                                         patients
                                     •   RAT testing on arrival

                              iii.       Patients unable to provide
                                         sufficient information on their
                                         symptoms or risk factors for
                                         COVID-19
                                     •   RAT testing on arrival

                             Group 3: Patient does not have
                             symptoms of, or epidemiological risk
                             factors for, COVID-19 infection.
                                 • no RAT or PCR testing needed.

                             RAT and PCR (collected at same time) if
                             a patient will be admitted to hospital

Hospitals (Public and N/A    Testing 72 hours pre-admission and/or RAT at home on the day of admission (or
Private sector)              RAT on arrival (vaccinated and on presentation).
planned          patient     unvaccinated).
presentations e.g. day
procedures          and      NB: Patients would need to isolate after a
multiday admissions          pre-admission PCR test until admission

Hospitals (Public and N/A    RAT on presentation at each visit. This to RAT at home prior to attendance; alert
Private sector) –            be reviewed with an aim to decrease clinic if positive
Patients at risk of severe   frequency      dependent   on      patient
disease e.g. patients        acceptability.
undergoing           renal
dialysis, chemotherapy
radiotherapy, transplant
patients,
immunosuppressed.

                                                                                12
Hospitals (Public and       Consider RAT on presentation at each For Emergency Department
Private sector)             visit.                               presentations – manage as above
- Paediatric patients
aged 5-11                                                         For planned admissions, labour ward,
- Maternity patients                                              birth suites – RAT on presentation

(Likely low vaccination
rates in these cohorts)

Aerosol generating          RAT on presentation                   RAT on presentation
procedures
As defined in
Mandatory Policy MP
0133/20

Hospitals (Public and N/A   No testing required.                  No testing required.
Private sector) –

outpatient attendances
–    clinics,  imaging,
pharmacy,     pathology
etc

                                                                            13
Domiciliary services      N/A                                            No testing required.                         No testing required.

e.g. Hospital in the
Home, Silver Chain,
Community        health
nursing

Hospitals (Public and     N/A
Private sector)                                                          RAT testing for visitors to high risk        RAT for visitors each visit if in a very
                                                                         settings and vulnerable patient cohorts      high-risk setting e.g. transplant ward,
 •   carers                                                              e.g. oncology wards, ICUs. Hospital          haematology unit, oncology ward, renal
     accompanying ED                                                     operator to determine high risk area for     dialysis unit etc
     patients                                                            that hospital
 •   visitors of
     inpatients                                                          RAT every third day for long term regular
 •   carers                                                              visitors
     accompanying
     children

Hospitals (Public and     N/A                                            No testing required.                         No testing required.
Private sector)

Contractors        and
suppliers

Asymptomatic Testing – Non-Hospital health settings
WA Health System Alert             Green: COVID-19 READY                         Amber: COVID-19 ALERT                 Red: Widespread        Black: SYSTEM
         Level                Disease contained, nil to very limited       Disease in community but still contained       transmission        AT CAPACITY
  (current definitions)         numbers increasing in community                                                             Community         Service demand
                            Satisfactory vaccination rates and testing                                                   transmission of      exceeds service
                                            capacity                                                                      COVID-19 no             capacity
                                                                                                                        longer contained

                                                                                                                                14
Ambulance staff            Tested at 48 hours, Day 7 and day 14   Voluntary twice weekly RAT with a   No testing required.
                           post contact with a confirmed case.    minimal interval 72 hours apart

Non-hospital health care
setting                                                           No testing required.                No testing required.

 •   WACHS remote area
     clinics
 •   WACHS remote
     nursing posts

                                                                                                               15
APPENDIX A: SARS-CoV-2 specific testing, Australia

TYPE OF TEST                     USES
Nucleic acid amplification testing Test of choice to detect SARS-CoV-2 during the acute
(NAAT) (PCR)                       illness.

                                 Can use pooling of specimens when pre-test probability
                                 of infection is low.

                                 Pooling not advised when infection rates are high
Rapid, low throughput, NAAT      To detect SARS-CoV-2 during the acute illness when a
(GeneXpert) (PCR)                rapid result is required.
                                 Limited to one sample at a time

Serology                         Retrospective diagnosis of infection when will influence
                                 individual or outbreak management.
                                 Not recommended as check of immunity post
                                 vaccination

Antigen testing (RAT)            Most accurate when used for the diagnosis of a SARS-
                                 CoV-2 infection in the early stages of symptomatic
                                 infection.
                                 They are intended for use with nasopharyngeal, throat
                                 or nasal swabs
                                 Any positive result must be confirmed by NAAT testing
Whole genome sequencing          WGS is used to compare the genomic relatedness from
(WGS)                            multiple COVID-19 cases to facilitate investigation of
                                 clusters by public health units.
                                 Used to detect and monitor for Variants of Concern
                                 (VoC)
                                 Monitoring for strains resistant to antiviral therapies,
                                 impact NAAT performance or vaccine effectiveness

Virus culture                    Limited use for diagnosis

Wastewater testing               Surveillance activities

                                                                                        Source: [6]

                                                                                               16
APPENDIX B: Rapid Antigen Testing (RAT)

Rapid Antigen Testing (RAT)

Established community transmission and maximum utilisation of laboratory PCR testing capacity will lead to
wider use of RAT to complement, but not replace, the PCR test as the gold standard test for diagnosis of
SARS CoV-2 infection [2]. RAT testing may be considered:

   1. In public health investigations where the pre-test probability is high for SARS CoV-2 infection. For
      example:
          a. Close contacts of a confirmed case in a closed setting e.g., schools, care homes, workplaces
          b. Broader contacts in a community for which it may inform isolation and quarantine strategies. In
              this situation it may need to be repeated regularly
          c. To rapidly identify an outbreak in a closed setting with several symptomatic individuals [11]
          d. When community transmission has been established.
   2. When the pre-test probability is high, and PCR is unavailable or where an extensive delay in
      turnaround time for results is anticipated but confirmatory testing by PCR is available.
   3. In situations where a false negative result is considered a reasonable risk and has minimal impact on
      the management of the individual.
   4. When RAT is used for screening purposes or as an initial diagnostic tool in high-risk exposure or
      transmission settings, to maximise the public health benefit, individuals should be screened two to
      three times a week to mitigate the reduced sensitivity of the test [12].
   5. For screening in certain settings for early detection of outbreaks. Daily testing would be considered to
      counteract the lower test sensitivity compared to PCR. For example:
      • Primary schools where children are not yet eligible for vaccination
      • Health care facilities
      • Aged care facilities
      • Food distribution centres
      • Meat, poultry, porcine processing centres
      • Construction sites
      • Mine sites
   6. In an outbreak setting, consideration of the potential impacts of false negative results from using RAT
      and the small proportion of cases that will be missed.
   7. The use of RAT should consider the potential impact on resources used to investigate false positive
      results in the setting of low prevalence.
   8. Then use of RAT may need to be revoked in the event of reduced test sensitivity caused by antigenic
      change in new variants [2].

                                                                                                Page 17 of 22
Advantages of RAT
   • Can be used at point-of-care
   • Rapid turnaround time to result (15-30 minutes)
   • Potential lower cost of PCR if only non-negative RATS are followed by PCR. Rapid antigen tests vary
      in cost but are usually between $10-$20 per unit. Additional implementation costs, including
      supervising workforce, personal protective equipment (PPE), waste management and results
      management need to be considered [3]
   • Ability to use as a self-test at home
   • Use for populations far removed from pathology services
   • With regular testing, enhanced confidence of lower likelihood of being infectious in the community; and
   • Can supplement laboratory-based PCR capacity [2].

Limitations of RAT
   • Lower sensitivity and specificity than PCR
   • Not recommended as a diagnostic tool where accuracy of every test is important to detect cases
   • PCR testing is preferred in symptomatic persons
   • Risk of false positives in areas of low prevalence
   • Labour intensive for supervised screening programs
   • Not scalable to large numbers of samples
   • Need for confirmatory PCR test for non-negative RAT results
   • Failure to undertake confirmatory PCR testing
   • Notification to Public Health is not automatic
   • Limited in the ability for genomic testing

                                                                                               Page 18 of 22
APPENDIX C: Current Directions for Testing

Relevant Directions to COVID-19 testing under the Emergency Management Act 2005 (WA) – subject
to change

OVERARCHING DIRECTION
  ▪ Controlled Border for Western Australia Directions (and Amendment Directions)

PRESENTATION FOR TESTING DIRECTIONS
  • Presentation for Testing Directions (No 37)
        o Premises Approved for the Purposes of Paragraph 17(b)(i)
  • Presentation for Testing (Airport Workers - Direct International Arrivals) Directions *
  • Quarantine Driver Directions*
  • Presentation for Testing (Quarantine Centre Workers) Directions (No 8)*
        o Authorisation under paragraph 14e and 15(f)
  • Transport and Accommodation Services (Exposed Maritime Worker) Directions (No 2)*
  • Exposed On-Board Worker Directions (No 2)*
  • Maritime Crew Member Directions (No 2)*
  • Rig or Platform Crew Member Directions (No 2)*
  • Transport, Freight and Logistics Directions (No 7)*
  • Flight Crew Directions (No 7)*
  • Exposure Site (Western Australia) Directions (No 2)*
  • Exposure Sites (Outside of Western Australia) Directions (No 3)
  • New South Wales Traveller Quarantine Modification Directions*
  • Outbreak Outside of Western Australia Response Directions (No 12) *

* Refer to applicable CHO approvals made under COVID-19 Testing Directions (PHA) for medical practitioners
and persons duly and properly engaged to collect specimens to request a COVID-19 test (due to person
presenting as asymptomatic)

Relevant Directions to COVID-19 testing under the Public Health Act 2016 (WA)

OVERARCHING DIRECTION
     COVID-19 Testing Direction (No 4)

CHO Approvals pursuant to above “Testing Directions”
  • Chief Health Officer Approval to Conduct COVID-19 Testing People Isolated or Quarantined (No 2)
  • Chief Health Officer Approval to Conduct COVID-19 PCR Testing at Point of Care in Remote Clinics
     (No 2)
  • Chief Health Officer Approval to Conduct COVID-19 Testing Before Proceeding with Organ Donation
     or Organ Transplantation (No 2)
  • Chief Health Officer Approval to Request COVID-19 Testing and Authorisation to Inform in relation to
     COVID-19 Detect Borders Initiative

                                                                                              Page 19 of 22
CHO approvals to request COVID-19 Testing on:
  • Patients who are Required to Provide Evidence of a Negative COVID-19 Test to Meet the Entry
     Requirements of Overseas Governments (No 3)
  • Persons who have Been to Locations Visited by Confirmed Cases (No 2)
  • Persons who are quarantine workers from anywhere in Australia

* CHO approvals to request COVID-19 Testing on persons who are presenting for testing under the:
   • Controlled Border for Western Australia Directions (AS AMENDED)
   • Presentation for Testing Directions (No 37)
   • Presentation for Testing (Airport Workers- International Arrivals) Directions (No 4)
   • Quarantine Driver Directions
   • Presentation for Testing (Quarantine Centre Workers) Directions (No 8)
   • Transport and Accommodation Services (Exposed Maritime Worker) Directions (No 2)
   • Exposed On-Board Worker Directions (No 2)
   • Maritime Crew Member Directions (No 2)
   • Rig or Platform Crew Member Directions (No 2)
   • Transport, Freight and Logistics Directions (No 9)
   • Flight Crew Directions (No.7)
   • Exposure Site (Western Australia) Directions (No 2)
   • Exposure Sites (Outside of Western Australia) Directions (No 2)
   • New South Wales Traveller Quarantine Modification Directions
   • Outbreak Outside of Western Australia Response Direction (No 12)

Note: Refer to Restatement of Approvals and Authorisations Directions, whereby the schedule of approvals
made under prior Testing Direction (No 2) continue to have effect under current amendment (No 3).

TESTING REPORTING DIRECTIONS
   ▪ COVID Testing Reporting Directions (No 2)
   ▪ Wastewater COVID Testing at WA Laboratories Reporting Directions (No 2)
   ▪ Wastewater COVID Testing at Laboratories Outside of WA Reporting Directions (No 2)

PROHIBITED TESTING DIRECTIONS
  ▪ Prohibition on the Use of Rapid Antigen Test Directions (No 2) Revocation Directions
  ▪ Prohibition on the Use of Point of Care Serology Tests Directions (No 2)

                                                                                           Page 20 of 22
Works Cited

[1] CDNA, “Considerations for COVID-19 Test, Trace, Isolate and Quarantine (TTIQ) in transition phases
    of the National Plan (Draft),” Communicable Diseases Network Australia, Canberra, 2021a.

[2] CDNA&PHLN, “Joint Statement on SARS-CoV-S version 201,” XX November 2021. [Online].
    Available: https://www.health.gov.au/resources.

[3] DHHS, “Guidance for the provision of rapid antigen testing for COVID-19 screening in non-clinical
    settings,” 05 October 2021a. [Online]. Available:
    https://www.dhhs.vic.gov.au/sites/default/files/documents/202110/Guidance-for-the-provision-of-
    RAT_1.pdf.

[4] DHHS, “Surveillance testing industry list and requirements.,” 11 November 2021b. [Online]. Available:
    https://www.health.vic.gov.au/covid-19/surveillance-testing-industry-list-covid-19.

[5] CDNA, “Revised Testing Framework for COVID-19 in Australia (draft),” XX November 2021b. [Online].
    Available: https://www.health.wa.gov.au/resources.

[6] Public Health Laboratory Network, “PHLN guidance on laboratory testing for SARS-CoV-2 version 2.1,”
    29 October 2021. [Online]. Available: https:www.health.gov.au/resources.

[7] Australian Health Protection Principal Committee, “AHPPC statement on the Omicron public healht
    implications and response options,” 22 December 2021. [Online]. Available:
    https://www.health.gov.au/news/ahppc-statement-on-the-omicron-public-health-implications-and-
    response-options.

[8] UK Health Security Agency, “SARS-CoV-2 variants of concern and variants under investigation in
    England,” 23 December 2021. [Online]. Available: https://assets.publishing.service.gov.uk.

[9] Ferguson N.,et al “Report 50: Hospitalisation risk for Omicron cases England,” 22 December 2021.
    [Online]. Available: https://www.imperial.ac.uk/media/imperial-college/medicine/mrc-gida/2021-12-22-
    COVID19-Report-50.pdf.

[10] NSW Education, “Response protocols for COVID-19 cases,” 27 November 2021. [Online]. Available:
     https://education.nsw.gov.au/covid-19/response-protocol.

[11] NSW Health, “Living Evidence - rapid testing (policy),” 22 November 2021b. [Online]. Available:
     https://aci.health.nsw.gov.au/covid-19/critical-intelligence-unit/living-evidence-rapid-testing.

[12] NSW Health, “Framework for the Provision of Rapid Antigen Screening for COVID-19 in Clinical and
     Non-Clinical Settings,” 23 August 2021a. [Online]. Available:
     https://www.nsw.gov.au/sites/default/files/2021-
     08/Framework%20and%20Standard%20Operating%20Procedure%20-%2022%20August.pdf.

[13] CDNA, “Australian National Disease Surveillence Plan for COVID-19,” 21 April 2021c. [Online].
     Available: https://www.health.gov.au/resources/publications/australian-national-disease-surveillance-
     plan-for-covid-19.

                                                                                                Page 21 of 22
Last updated 10 January 2022 – V3.0 SHICC PHAB
This document can be made available in alternative formats
on request for a person with disability.

© Department of Health 2022

Copyright to this material is vested in the State of Western Australia unless otherwise indicated. Apart from
any fair dealing for the purposes of private study, research, criticism, or review, as permitted under the
provisions of the Copyright Act 1968, no part may be reproduced or re-used for any purposes whatsoever
without written permission of the State of Western Australia

                                                                                                Page 22 of 22
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