A statement from the Australian Health Protection Principal Committee (AHPPC) on rapid antigen testing for current high community prevalence environment.
Context
The Omicron COVID-19 variant of concern has demonstrated significant community transmission, despite high rates of vaccination. As a result, a high case burden is expected for a significant period of time.
PCR testing capacity is finite and has been further constrained by the inability to pool samples given high positivity rates, the impact of high community transmission on staff infections and furlough periods, and supply chain constraints (e.g. for reagents).
Current management of COVID-19 relies on timely laboratory PCR testing notification. Increased turnaround times for collection, PCR testing and results will lead to delayed linkage to care and specific therapies, and identification of high-risk contacts. A shift to the increased use of rapid antigen testing as an alternative diagnostic rather than a screening test is therefore required. In moving to rapid antigen testing, new approaches will be required to identify cases and contacts, to ensure that those patients at increased risk of more severe disease, and those that would benefit from treatment interventions are linked to care, and that PCR testing with appropriate turnaround times is available as needed. Proposed use of rapid antigen testing (RAT)
It is proposed that rapid antigen tests can be used for the following 3 purposes:
As a diagnostic test as an alternative to PCR for those at high risk of having COVID-19. In most circumstances in the current high-prevalence environment, a positive rapid antigen test should be accepted as a diagnosis of COVID-19.
To manage outbreaks.
To help early identification of cases in high-risk settings.
1 – Using RAT as a diagnostic test as an alternative to PCR for those at high risk of having COVID-19
Cohort
1
Testing Recommendation
2
Comment
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People residing in the household with a known COVID-19 case
RAT on notification and Day 6
Additional RAT if symptomatic
Positive RAT should be considered confirmed COVID-19 case regardless of symptoms.
If essential for safe service delivery will require risk management plan in place by employer including:
Where essential services will be disrupted:
Depending on risk assessment and other risk mitigations applied, continue to work if negative first RAT and asymptomatic, RAT at least ever second day up to Day 6.
In normal essential service settings:
Quarantine for 7 days, with a RAT test on Day 1 and Day 6.'
Staff should not attend the workplace if symptomatic.
4
People who have had a high-risk exposure to a known COVID-19 case
5
Symptomatic people (who have not had a high-risk exposure)
RAT as soon as possible
If negative, isolate and repeat RAT in 24 hours, or seek immediate PCR
Positive RAT should be considered confirmed COVID-19 case.
If both RATs are negative, isolate until symptoms have resolved, or
Isolate until negative PCR received and symptoms have resolved.
2 – Using RAT to manage outbreaks
Cohort
1
Testing Recommendation
2
Comment
3
High-risk settings (healthcare, aged care, disability care, correctional facilities)
RAT testing to identify initial extent in the facility.
Confirmatory PCR test for initial case(s) only. Subsequent Day 6 and Day 12 RAT to assess outbreak progress. Day 12 swab to declare the outbreak over may be PCR.
4
Other industry, businesses, organisations, etc
RAT testing of staff may help to identify the extent of transmission in workplace settings.
Industry should consider how they will respond to COVID-19 outbreaks in their workplace. This may include daily RAT for staff in addition to other controls already in place.
3 – Using RAT to detect cases early in high-risk settings
Cohort
1
Testing Recommendation
2
Comment
3
Residential aged and disability care settings where there is high community prevalence
Daily RAT for all staff (minimum twice weekly where supply constraints exist)
RAT for visitors at each visit
This regime is subject to local consideration of community prevalence and availability of RAT.
4
Healthcare settings managing very high-risk patients (e.g. transplant ward, haematology unit, oncology ward, renal dialysis unit)
5
Other critical services (e.g. other parts of healthcare services, emergency services)
In specific circumstances, in consultation with Health authorities
Suitable regime determined by respective industry and settings to manage business continuity of supply/service, noting that other risk mitigants may adequately manage risks and RAT may be used supplementary to these.
6
Other industry, businesses, organisations, etc
Not routinely recommended
Industry may review and introduce surveillance testing according to individual industry risk assessment.
