Department of Health

Victorian COVID-19 testing criteria

9 April 2021

  • Fever OR chills in the absence of an alternative diagnosis that explains the clinical presentation* 

OR

  • Acute respiratory infection (including cough, sore throat, shortness of breath, runny nose)** 

OR 

  • Loss of smell or loss of taste. 

*Clinical discretion applies; consider potential for co-infection (such as SARS-CoV-2 and influenza). 

**Older people may present with other atypical symptoms including functional decline, delirium, exacerbation of underlying chronic condition, falls, loss of appetite, malaise, nausea, diarrhoea and myalgia. 

Other clinical symptoms 

People in the following groups should be tested if they have new onset of other clinical symptoms associated with COVID-19 (including headache, myalgia, stuffy nose, nausea, vomiting or diarrhoea): 

  • people who are most at risk of severe illness 
  • higher prevalence groups and settings 
  • settings with a high risk of transmission. 

Clinical judgement and reasoningshould be used, including consideration of epidemiological risk factors for acquisition and transmission. 

Case definitions

Confirmed case

A confirmed case requires laboratory definitive evidence. 

  • Detection of SARS-CoV-2 by nucleic acid testing.1

OR 

  • Isolation of SARS-CoV-2 in cell culture, with confirmation using a nucleic acid test.

OR

  • SARS-CoV-2 IgG seroconversion or a four-fold or greater increase in SARS-CoV-2 antibodies of any immunoglobulin subclass including ‘total’ assays in acute and convalescent sera, in the absence of vaccination.2

Historical case

  • A historical case requires laboratory suggestive evidence supported by either previous (prior to the past 14 days) clinical evidence.

OR

  • Previous (prior to the past 14 days) epidemiological evidence. 

A historical case should not have any symptoms of COVID-19 (or not have had symptoms of COVID-19 for the past 14 days). 

Laboratory suggestive evidence

  • Detection of SARS-CoV-2 by polymerase chain reaction (PCR) on two specimens at least 24 hours apart with high Ct values3 on both specimens AND detection of IgG or total antibody, in the absence of vaccination.2,4

OR

  • Negative PCR result AND detection of IgG or total antibody, in the absence of vaccination.2

OR

  • High PCR Ct result on first result, and higher PCR Ct result or negative PCR result on second test, taken >24 hours apart.2

Clinical evidence

  • History of measured (≥37.5°C) or self-reported fever (for example, night sweats, chills).

OR

  • History of an acute respiratory infection (for example, cough, shortness of breath, sore throat). 
  • Loss of smell or taste.

Epidemiological evidence

In the 14 days prior to illness onset: 

  • close contact with a confirmed case
  • international travel
  • workers supporting designated COVID-19 quarantine and isolation services
  • international border staff
  • air and maritime crew
  • health, aged or residential care workers and staff with potential COVID-19 patient contact
  • people who have been in a setting where there is a COVID-19 case
  • people who have been in areas with recent local transmission of SARS-CoV-26.

Notes

  1. There is possibility for false negative PCR (polymerase chain reaction) results in children, who may mount a brisk immune response resulting in a lower viral load. Public health units may seek serological evidence of SARS-CoV-2 immunity in symptomatic children who are repeatedly PCR negative but are known primary close contacts.  
  2. Antibody detection must be by a validated assay and included in an external quality assurance program. For all serological responses to be counted as laboratory evidence, a person should not have had a recent history of COVID-19 vaccination. 
  3. The cycle threshold (Ct) value of a reaction is the cycle number when the fluorescence of a PCR product is first detected above the background signal. The lower the Ct value, the more virus is present in the sample being tested, as fewer amplification cycles are required before the threshold for detection is met. A high Ct value generally indicates that more cycles are required to detect the virus, indicating that there is less viral RNA present in the sample. Each PCR assay may have a different Ct value that is used for detecting SARS-CoV-2. Ct values for one in-vitro diagnostic (IVD) device should not be compared with Ct values from other platforms. This means there is no ‘set’ Ct value to aim for across all platforms. High Ct values are as defined in consultation with the responsible supervising pathologist. 
  4. Occasionally a person may have a positive PCR result, with high Ct values, on a subset of gene targets in the PCR assay/s used. These scenarios may be due to acute infection but could also represent previous infection (that is, intermittent/persistent SARS-CoV-2 shedding in a historical case), sometimes with a concurrent upper respiratory tract infection due to another organism. A further swab collected at least 24 hours after the positive sample and serology testing can assist in distinguishing an acute from a historical COVID-19 infection. If the person is symptomatic, a full respiratory panel for other pathogens should be done. 

Case notification 

Both confirmed and historical cases need to be notified to the Department of Health as soon as practicable by either:

People who have previously been diagnosed and managed overseas or in another Australian jurisdiction do not need to be notified as a confirmed or historical case. 

Key resources

Please ensure you refer to the latest version of the guideline documents as guidance may change.

This resource is also listed in the popular resources section on the For health services and professionals - COVID-19 page

Testing criteria

    Who should not be tested for COVID-19?

    Patients without symptoms should not be tested except in special circumstances or where requested by the department:

    • as part of an outbreak investigation/response (active case finding)
    • for all primary close contacts and returned international travellers at the start and the end of quarantine
    • prior to surgery
    • as part of enhanced surveillance to:
      • investigate how widespread COVID-19 is in the community, or
      • detect and reduce transmission, particularly in higher prevalence groups and settings, and settings with a high risk of transmission.

    Testing children

    • The same testing criteria applies to adults and children of all ages.
    • For advice on testing technique in children refer to the COVID-19 swabbing clinical practice guidelines (Royal Children's Hospital)
    • Where possible, all family members (parents/carers and children) who meet the testing criteria should be tested at the one location. For advice on which testing sites children can attend for testing refer to getting tested
    • Asymptomatic parents/carers are not required to self-isolate whilst their child is awaiting their swab results (unless told to by the Department of Health) 

    Testing aged care residents

    The Centre of Clinical Excellence - Older People at Safer Care Victoria provides a COVID-19 screening tool for residential aged care services to identify typical and atypical signs of COVID-19 in aged care residents. 

    How is COVID-19 excluded in symptomatic patients?

    For patients with fever or respiratory tract infection who are not hospitalised and who do not have an epidemiological link to a known COVID-19 case, a single negative oropharyngeal and deep nasal swab (plus sputum if possible) is sufficient to exclude COVID-19 infection.

    Repeat testing (especially of lower respiratory tract specimens) in clinically compatible cases should be performed if initial results are negative and there remains a high index of suspicion of infection. In unwell patients, consideration should also be given to a respiratory virus panel test, especially if the first COVID-19 test is negative.

    Hay fever and asthma

    Clinical judgement should be used to decide whether rhinorrhoea represents possible COVID-19 (requiring testing) or allergic rhinitis. There should be a low threshold for testing for COVID-19, particularly if the symptoms are different to the patient’s usual hay fever or asthma symptoms.

    Factors that would make allergic rhinitis more likely include:

    • history of allergic rhinitis in previous years at a similar time of year
    • concomitant itchy nose and eyes
    • response to usual treatments.

    Factors that would make COVID-19 more likely include:

    • other respiratory symptoms (sore throat, cough, anosmia)
    • systemic symptoms (such as fever, myalgia, anorexia)
    • no or minimal response to usual treatments.

    People with known allergic rhinitis or asthma should have:

    • their treatment optimised, including through having an up-to-date asthma action plan or hay fever treatment plan
    • advice about what symptoms might suggest COVID-19 infection and require them to immediately get tested for COVID-19 and stay home until a negative result is received.

    Assessment and procedures

    Assessing a patient with respiratory symptoms in a community setting

    • Separate them from other patients.
    • Place a single-use surgical mask on the patient.
    • Use personal protective equipment (PPE) when assessing the patient (gown, gloves, eye protection and single-use face mask).
    • Conduct a medical assessment, and focus on:
      • date of onset of illness and especially whether there are symptoms or signs of pneumonia
      • contact with confirmed or historical cases of COVID-19
      • precise travel history and occupation
      • history of contact with sick people, travellers, or healthcare facilities
      • work or residence in higher prevalence groups and settings, settings with a high risk of transmission or other priority settings and groups
      • co-morbidities – see 'People who are most at risk of severe illness' on Clinical guidance and resources - COVID-19.

    All patients should attend an emergency department if clinical deterioration occurs. If clinically required, ambulance transport should be used - advise 000 operator of suspected COVID-19.

    Taking a COVID-19 swab

    If you have a patient who meets the criteria for COVID-19 testing (and who does not have symptoms or signs of pneumonia):

    • Place a surgical mask on the patient and isolate them in a single room with door closed.
    • Use personal protective equipment (PPE) (single-use surgical face mask, eye protection, gown and gloves).
    • Take a single oropharyngeal and deep nasal swab for COVID-19 PCR. To conserve swabs, use the same swab to sample the oropharynx and for deep nose sampling (that is, one swab per patient only).
    • Oropharyngeal (throat): swab the tonsillar beds and the back of the throat, avoiding the tongue.
    • Deep nasal:
      • Using a pencil grip, gently rotate the swab, while inserting the tip 2-3 cm (or until resistance is met) into the nostril, parallel to the palate, to absorb mucoid secretion.
      • Rotate the swab several times against the nasal wall. 
      • Withdraw the swab and repeat the process in the other nostril.
    • Place the swab back into the accompanying transport medium.

    If appropriate personal protective equipment is not available, direct the patient to the nearest COVID-19 testing centre.

    Patients with symptoms and signs suggestive of pneumonia should be tested and treated in hospital.

    Do patients need to isolate whilst waiting for test results?

    People who are symptomatic at the time of testing for COVID-19 should isolate until COVID-19 is excluded, unless advised to isolate for longer by the department. If their test is negative, they should continue to isolate until the acute symptoms have resolved and they feel well.

    People who are asymptomatic at the time of testing for COVID-19 should isolate until COVID-19 is excluded, unless advised otherwise by the department. Some asymptomatic people will not be required to quarantine after testing, such as people tested as part of a surveillance testing or other targeted testing program.

    Tests currently available for COVID-19

    PCR-based tests

    Molecular testing on a well-collected single throat and deep nasal swab is the current test of choice for the diagnosis of acute COVID-19 infection.

    Molecular tests use real-time polymerase chain reaction (PCR) to look for evidence of the genetic material (RNA) of SARS-CoV-2 (the virus that causes COVID-19).

    A positive PCR result indicates current or very recent infection. SARS-CoV-2 RNA is generally detectable in respiratory specimens from about one day prior to symptom onset, and during the acute phase of infection.

    A negative PCR result means that SARS-CoV-2 RNA was not identified in the sample. Negative results do not preclude SARS-CoV-2 infection, and interpretation of such results should be combined with clinical observations, patient history, and epidemiological information. 

    Rapid antigen testing

    Rapid antigen tests are now required as a screening tool for COVID-19 in some workplaces in Victoria. Workers are tested prior to entry to the workplace by health professionals. If a worker tests positive to COVID-19, their results are provided to the Department of Health via an online form. 

    For all positive RAT COVID-19 result notifications please fill out the Rapid Antigen Test (RAT) Form.

    If a worker tests positive to COVID-19 using a rapid antigen test, the department will follow up to ensure a confirmatory PCR test is performed and matched against the positive rapid antigen test.

    These tests can be performed by health professionals, as outlined by the TGA, outside of the laboratory, and can give a result within 15 to 20 minutes.

    Because rapid antigen tests are less sensitive at detecting COVID-19 than PCR-based assays and can vary in performance, they are considered to be a screening tool for COVID-19.

    The use of antigen-based screening is part of a responsive and adaptive testing system, and is determined by epidemiology and the phase of the public health response in Victoria.

    The Victorian Government is supporting adoption of rapid antigen screening for COVID-19 in the following contexts:

    1. High-frequency screening for surveillance (except in highest-risk settings where PCR testing is required) where screening testing is repeated at least three (3) times per week.

    2. A combined rapid antigen and PCR test where an early antigen test result can assist with triaging people quickly while awaiting their PCR-result.

    The Victorian Government continues to advise against the use of rapid antigen tests to diagnose acute SARS-CoV-2 infection in symptomatic persons. In Victoria and Australia, reverse transcription-polymerase chain reaction (RT-PCR) testing is the accepted diagnostic test for acute SARS-CoV-2 infections.

    All positive antigen-based screening results require reporting to the Department of Health using the Rapid Antigen Test (RAT) Form and follow-up PCR testing for confirmatory diagnosis.

    The Department of Health will continue to review this policy position as new evidence and experience emerges.

    Resources are available detailing how to implement rapid antigen testing:

    The Australian Prostate Centre has developed a video and accompanying booklet guide to setting up and performing rapid antigen testing for COVID-19.

    Notifying patients and the department

    Medical practitioners should notify the Department of Health of confirmed and historical cases as soon as possible by either: 

    General practitioners notifying patients

    General practitioners should ensure arrangements are in place for contacting the patient with their COVID-19 test result, regardless of whether it is negative or positive.

    If the result is positive, notify the Department of Health by either calling 1300 651 160 or using the online COVID-19 notification form.

    All confirmed cases of COVID-19 must  isolate until they are cleared by the Department of Health or a nominated representative.

    Health service clinicians notifying patients

    Testing clinics and health services should ensure arrangements are in place for contacting the patient with their test result, regardless of whether it is negative or positive.

    If the result is positive, the health service infectious diseases lead, or senior clinician should notify the Department of Health by either:

    All confirmed cases of COVID-19 must  isolate until they are cleared by the Department of Health or a nominated representative.

    Contact from the Department of Health

    The department receives notification from laboratories of all positive results and contacts confirmed cases (people who test positive). The department may contact a patient before the treating doctor to inform the patient of their result – this ensures that case contact interviews, communications and contact tracing are timely. 

    Even if the department has already contacted a patient with a positive COVID-19 test result, the treating doctor or clinical team representative (as appropriate) should still contact the patient. This is important to ensure that:

    • the patient has received their result
    • any clinical queries have been addressed
    • there is a clear management plan in place.

    To provide any additional clinical information, clinicians should call the department on 1300 651 160

    All confirmed cases of COVID-19 must  isolate until they are cleared by the Department of Health or a nominated representative.

    Reviewed 16 November 2021

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