At a glance

In Queensland, the COVID-19 pandemic has broadly occurred in two phases: a) keeping the virus out for as long as possible until high levels of vaccination coverage were achieved (2020-2021); and b) protecting those at highest-risk (2022).

As at 31 January 2023:

  • Over 80% of adults were estimated to have been infected at least once based on antibody testing of blood donors1
  • 1.6 million positive COVID-19 swabs had been reported in Queensland. 98% were reported in 2022. Most cases (54.5%) were identified through self-reported rapid antigen tests (RATs)
  • Daily counts of public hospital bed occupancy for people with COVID-19 peaked at between 509 to 977 during each of the four waves during 2022. Each wave was attributed to different sub-lineages of the Omicron variant
  • 92.2% of eligible people over 16 years had received at least two doses of vaccine
  • 1,757 people had died from COVID-19 in Queensland (33.9 per 100,000 population).2 This number is very low by global standards (about one-tenth the rate reported in the USA).

Introduction

The SARS-CoV-2 (coronavirus disease 2019 (COVID-19)) global pandemic is one of the foremost public health crises in living memory resulting in substantial morbidity and mortality. The first cases of 'pneumonia with an unknown cause' were detected in Wuhan, China, and were notified to the World Health Organization (WHO) in December 2019.3

The first case in Australia was detected on 25 January 2020 in Victoria while the first Queensland case was detected soon after. Public health actions of test, trace, isolate and quarantine (TTIQ) were undertaken as part of an elimination strategy to disrupt transmission chains.

The initial success of high population levels of vaccine uptake enabled Queensland to open the State borders and shift from a phase where the focus was on keeping the virus out for as long as practicable to then aiming to protect those at highest risk of hospitalisation and death from COVID-19. New variants of concern (VoC) for COVID-19 were expected to emerge, with the likelihood that some would have the potential to behave differently to other virus strains. Undertaking whole genomic sequencing of the circulating strains helped to confirm whether variants were significantly more transmissible and/or caused more severe disease which then informed the public health response to COVID-19.

This feature summarises the health events from the first case of COVID-19 through until near the end of the fourth wave of community transmission in Queensland on 31 January 2023. The essential public health advice that remains in place today is to:

  • stay home if you’re sick
  • keep up to date with your vaccinations
  • take a rapid test (RAT) if you get COVID-19 symptoms
  • if you get COVID-19
    • register your RAT result
    • stay home until you’re well again
    • wear a mask for 7 days after your test
    • avoid visiting hospitals, aged care or disability care for 7 days after your test
    • ask household members to closely monitor for symptoms
    • wash your hands
    • wear a mask if required by the health care provider, venue or household.

'Keeping the virus out' January 2020 to 2 May 2021

In Queensland, the first confirmed case of COVID-19 was detected from a specimen collected on 28 January 2020 in a cluster of five travellers from mainland China. Case numbers increased rapidly in March 2020, doubling every four days and peaking at 73 cases per day before declining until mid-April. From 15 April to June 2020, the number of new cases markedly reduced and remained low, with no more than five cases detected daily throughout this period.

Following the initial incursions of the virus into Queensland, the period July 2020 to 2 May 2021 was characterised by relatively low numbers of new cases and containment of sporadic outbreaks/clusters with very large numbers of potential contacts at risk of infection. One of the largest outbreaks during this period involved 50 cases and over 2,400 contacts traced across multiple Hospital and Health Service areas between 21 July 2020 and 8 October 2020:

  • On 21 July 2020, two COVID-19 infected travellers returned from interstate resulting in a cluster of five cases exposed in South Brisbane.
  • On 19 August 2020, Queensland Health received a notification of a confirmed COVID-19 case who was working at a correctional facility. The case was potentially linked to the previous cluster involving the returned interstate travellers.
  • From 20 August to 15 September 2020, further cases were detected involving high-risk settings including correctional facilities, schools, a hospital, residential aged care facility and childcare centre.

In February 2021, SARS-CoV-2 vaccination commenced across Queensland targeting priority populations including quarantine and border workers, frontline health care and aged care workers. In response to COVID-19 outbreaks, Queensland Health commenced a vaccination program targeting First Nations people in the rural and remote locations from March 2021, ahead of the national roll-out. Prior to the availability of an effective vaccine, successful public health management included:

  • Intensive contact tracing, large-scale and targeted testing events, whole genome sequencing of available samples, and multi-site decentralised incident teams.
  • Short-term local or state-wide lockdowns were implemented in response to escalating case numbers.
  • High SARS-CoV-2 testing coverage from the commencement of the pandemic resulted in unprecedented testing as the result of state-wide encouragement of testing, supported through early and ongoing collaboration with public and private laboratories.
  • Centralised interpretation of SARS-CoV-2 laboratory results included the use of rapid real-time SARS-CoV-2 genomics by Queensland Health Forensic and Scientific Services (FSS) and interpretation of whether a result was a new or previous COVID-19 infection to guide the public health response.

From January 2020 to 2 May 2021, there were 1,582 cases, the majority of which were acquired overseas (79%), or were a contact of a confirmed case or in a known cluster (17%). Over this time period, genomic testing indicated the detection of an 'alpha' variant. Seven COVID-19 deaths were reported during this period.

'Emergence of the Delta variant' 3 May 2021

The 'Delta' variant (B.1.617.2) was first detected on 4 May 2021 from an international traveller while in hotel quarantine. In late July 2021, Queensland Health was notified of a case in a school-aged child with an unknown source of infection. The case was reported as the Delta variant and clustered genomically with two overseas-acquired cases detected in hotel quarantine weeks prior. This signalled the largest single outbreak in Queensland to that point, ultimately involving 147 laboratory-confirmed cases among students and staff from five educational facilities, as well as their contacts in the Brisbane metropolitan area.

There had been a cumulative total of 2,210 cases (Figure 1) with 599 of cases occurring during the period when the 'Delta' variant was predominant but there were no additional COVID-19 deaths. Of the 599 additional cases, 53% were acquired overseas, 39% were linked to outbreaks or clusters and 8% were acquired locally without a link to a known contact or were undetermined. Of the Queensland eligible population 16 years and over, 88.3% had received their first vaccination dose and 81.3% had received a second dose.

Figure 1: Queensland reported weekly COVID-19 cases, 28 January 2020 to 12 December 2021
Bar and line graphs displaying the number of COVD-19 cases and cumulative counts from 28 January 2020 to 7 December 2021, with a peak between March and April 2020

'Omicron variants'

On 13 December 2021, when 80% of eligible people in Queensland had been vaccinated, Queensland borders were opened to domestic and international travellers in Australia. Following the subsequent increase in domestic and international arrivals, case numbers rose steeply to 397,103 by 30 January 2022 (Figure 2).

Figure 2: Queensland reported weekly COVID-19 cases, 13 December 2021 to 31 January 2023
Bar and line graphs displaying the number of COVD-19 cases and cumulative counts from 8 December 2021 to 31 January 2023 by report type

The increase in case numbers was reflected in a rapid shift to Omicron (B.1.1.529/BA.1) as the dominant variant in Queensland by the week ending 26 December 2021. The first case of the Omicron (B.1.1.529/BA.1) variant of SARS-CoV-2 was detected in a sample collected on 6 December 2022 in an international traveller. Four distinct waves of COVID-19 occurred through 2022 and into 2023 typically peaking after 5-6 weeks and persisting for 12 weeks (Figure 2 and 3).

During the first wave of widespread community transmission when Omicron (B.1.1.529/BA.1) was predominant:

  • There were 596,143 cases reported amongst people with COVID-19 over 13 weeks from 13 December 2021 until to 13 March 2022.
  • The daily number of cases peaked at over 20,000 cases on 5 January 2022, while the number of public hospital beds occupied by people with COVID-19 peaked at 928 on 24 January 2022 (Figure 3).

A second wave of community transmission commenced on 14 March 2022, attributed to the BA.2 sub-lineage which was the predominant strain by the week ending 27 March 2022. This was a sub-lineage first detected by FSS in a returned traveller who was in isolation. FSS raised international awareness of this 'Omicron-like' sequence on 5 December 2021.

  • There were 530,893 cases reported amongst people with COVID-19 over 13 weeks from 14 March 2022 to 12 June 2022. The number of public hospital beds occupied by people with COVID-19 peaked at 537 on 19 April 2022.

A third wave, attributed to BA.4 and BA.5 sub-lineages of the Omicron variant, commenced on 13 June 2022.

  • There were 396,964 cases reported amongst people with COVID-19 over 21 weeks from 13 June 2022 to 6 November 2022. The number of public hospital beds occupied by people with COVID-19 peaked at 977 on 25 July 2022.

A fourth wave, attributed mainly to BA.2.75 sub-lineages of the Omicron variant, commenced on 7 November 2022.

  • There were 110,315 cases reported amongst people with COVID-19 over 12 weeks and 2 days from 7 November 2022 to 31 January 2023. The number of public hospital beds occupied by people with COVID-19 peaked at 509 on 19 December 2022.
Figure 3: Hospital bed occupancy by people diagnosed with COVID-19 in Queensland, 13 December 2021 to 31 January 2023
Plot of hospital bed occupancy by people diagnosed with COVID-19 for 4 waves in Queensland since December 2021, where the highest bed occupancy was during waves 1 and 3.

Cumulatively by 31 January 2023, there were 1,725,070 COVID-19 cases reported in Queensland and 1,757 deaths attributed to COVID-19.2 The crude case fatality rate was 0.1%. Overall, 5.7% of cases were identified as reinfections increasing from 0.3% during the first wave to 18.6% during the fourth wave.

Of course the true number of infections acquired in Queensland significantly exceeds the number actually diagnosed and reported.  The best estimate we have of the number of Queenslanders who have truly experienced COVID-19 to date is based on the COVID-19 serosurveillance study of Australian blood donors.1 As of 13 December 2022, 67.7% of Queensland blood donors had detectable antibodies to nucleocapsid antigen. The test used is believed to underestimate the incidence of previous infection by 15-20%. This suggests that the true proportion of Queenslanders who had experienced COVID-19 at least once prior to 13 December 2022 was about 80 to 90%.

The number of deaths attributable to COVID-19 either directly or indirectly may be underestimated by death certificate reports. This might occur because the diagnosis is not established before death or death is an indirect effect of infection. One way to try to quantify this is to look at 'excess deaths' (ie how many more people died in Queensland than was predicted statistically). The Actuaries Institute Australia estimated that 3,800 more Queenslanders died between 1 January 2022 and 27 November 2002 than was predicted.4 This number is significantly higher than formally reported deaths attributed to COVID-19 in 2022.

During 2022:

  • 31.0% of adults were diagnosed with COVID-19. Adults 18 to 29 years (409.1 per 1,000) had the highest crude case rates while those adults 70 years and older (164.9 per 1,000) were the lowest
  • females (319.6 per 1,000) had higher crude case rates than males (269.5 per 1,000)
  • First Nations peoples (398.5 per 1,000) had higher crude case rates than other Queenslanders (297.5 per 1,000).

SARS-CoV-2 diagnostic tools and testing requirements in Queensland changed as the increase of COVID-19 cases reduced the capacity to sustain laboratory-based polymerase chain reaction (PCR) testing and with the emergence self-performed Rapid Antigen Tests (RATs).

  • An online RAT portal for self-reporting was launched from 7 January 2022.
  • By 31 January 2023, there were 892,417 COVID-19 cases identified solely through the RAT online portal (54.5% of total cases).

Individuals with a higher risk of severe disease, international travellers and close contacts continue to be encouraged to seek the gold standard PCR diagnostic testing, which has a higher accuracy and sensitivity. This allows targeted monitoring of the ongoing circulation of SARS-COV-2, early detection of the emergence of new variants and recombination of existing variants, and co-infection with other respiratory pathogens.

Health information management processes adapted rapidly during the course of the pandemic. This included improved linkage between notifiable conditions information and other administrative health data sets such as vaccination status and disease severity measures for patients admitted to hospital or Intensive Care Units (ICU). This, in combination with monitoring for new variants of concern, allowed more complete epidemiological, clinical and laboratory assessment of potential public health threats and will have ongoing benefit in supporting health services and public health responses more broadly.

The rapid evolution of the virus in our communities locally and globally has required an innovative response with vaccines and continued primary prevention measures such as mask-wearing and social distancing. While we have moved on from lockdowns and border closures in Queensland, we continue to remain cautious of new VoCs that have potential to impact vaccine effectiveness against severe disease.

Some health experts believe that the world was informed yet ill-prepared to respond to the COVID-19 pandemic.5 One of the most valuable tools that we have in Queensland is our experience in responding to COVID-19 in the last three years. The community performed exceptionally well when compared to other global settings and repeatedly lead by example in demonstrating effective control of localised community transmission. While other countries were experiencing crippling spikes in cases and deaths, Queenslanders largely remained safe. Our strong response and commitment to safety measures was an incredible sacrifice that afforded us the critical time we needed to protect our communities with vaccines. We have since been rewarded with one of the lowest mortality rates in the world.

The COVID-19 pandemic is not over. We aim to keep the risk of death and other severe outcomes from COVID-19 infection as low as possible. This includes ensuring eligible Queenslanders remain up-to-date with their SARS-CoV-2 vaccinations to provide the best available protection against severe disease. Importantly, there is also a need to establish continued support systems for those suffering from prolonged effects of COVID-19 ('long COVID').6

Additional information

Section technical notes

Data for this section were sourced from the Queensland Health Notifiable Condition System (NoCS) between 1 January 2020 and 31 January 2023. Data were extracted on 6 March 2023 with the following caveats:

Cases

  • COVID-19 cases from Queensland were notified to NoCS and included self-reported COVID-19 RAT Portal results that had been established as pipeline into NoCS.
  • The COVID-19 case definition, including the criteria to distinguish a new case from an existing case in NoCS is as per the CDNA Series of National Guidelines for Public Health Units.
  • Cases notified to NoCS data are reported as per the date the PCR or RAT test was collected. For cases who were positive on both PCR and a RAT during the same COVID-19 episode, the case is reported as a confirmed COVID-19 case and earliest test is used.
  • Cases self-reported on the online RAT portal are reported as per submission date.
  • Differences between the numbers reported here and in other public facing reports may be due to differences in data cleaning and extraction methodology.

Rates

  • Crude case and death population rates are presented in this report.
  • Rates are calculated by dividing cases by the relevant Estimated Resident Population of Queensland as at June 2020 per 1,000 or 100,000 population as indicated.

Deaths

  • COVID-19 deaths are defined for surveillance purposes as per the COVID-19 death definition outlined in the COVID-19 Series of National Guidelines (SoNG):

“A COVID-19 death is defined for surveillance purposes as a death in a confirmed or probable COVID-19 case, unless there is a clear alternative cause of death that cannot be related to COVID-19 (e.g. trauma). There should be no period of complete recovery from COVID-19 between illness and death. Where a Coroner’s report is available, these findings are to be observed”.

  • COVID-19 deaths are reported based on the date the person died.
  • Deaths due to COVID-19 are not in themselves notifiable and Queensland Health obtains information about deaths from a variety of sources. The treating clinician will typically assess the role COVID-19 may have played in the death of a patient.
  • There may be a delay in COVID-19 deaths being reported due to several reasons.

Age groups

  • Excludes cases where age is missing.

Sex

  • Excludes cases where sex is missing.
  • Includes positive cases on NoCS. Case data on sex is not captured on the online RAT portal.

First Nations Status

  • Excludes cases where First Nations status is missing. The number of cases classified as First Nations is likely to be an underrepresentation.

Hospital and Health Service

  • Cases are assigned based on their reported residential address. Some cases are reported who reside in a jurisdiction other than Queensland where public health management and address were reported in Queensland.
  • Hospital and Health Service (HHS) is assigned based on geocoded residential addresses using postcode and suburb.
  • Excludes cases where postcode and/or suburb is missing or a jurisdiction other than Queensland.

Remoteness

  • Remoteness is assigned using Postal Areas (POAs) as per the Australian Statistical Geography Standard Remoteness Structure (2016). Remote and very remote areas are combined.
  • Excludes cases where POA of residence is missing, incorrect, a GPO box or in another jurisdiction.
  • Data should be interpreted with caution as POAs are not geocoded and imprecise measures of remoteness.
  • Remoteness for vaccination status is classified using HHS boundaries where ‘Metro (SEQ)’ includes Metro North, Metro South, West Moreton, Gold Coast, and Sunshine Coast HHSs; ‘Regional’ includes Cairns and Hinterland, Townsville, Mackay, Central Queensland, Wide Bay, and Darling Downs HHSs; and ‘Remote’ includes Torres and Cape, North West, Central West, and South West HHSs.

Primary Health Network

  • Primary Health Network (PHN) is calculated using HHS boundaries including: Brisbane North PHN (Metro North HHS), Brisbane South Metro (Metro South HHS), Gold Coast PHN (Gold Coast HHS), Central Queensland Wide Bay Sunshine Coast PHN (Central Queensland HHS, Wide Bay HHS and Sunshine Coast HHS), Darling Downs and West Moreton PHN (Darling Downs HHS and West Moreton HHS), North Queensland PHN (Townsville HHS, Cairns and Hinterland HHS , Mackay HHS and Torres and Cape HHS) and Western Queensland PHN (Central West HHS, North West HHS and South West HHS).

Socio-Economic Indexes for Areas (Index of Relative Socio-economic Advantage and Disadvantage)

  • Index of Relative Socio-Economic Advantage and Disadvantage (IRSAD) is assigned using POAs.
  • Excludes cases where POA is missing, incorrect, a GPO box or in another jurisdiction.
  • Data should be interpreted with caution as POAs are not geocoded and imprecise measures of SEIFA IRSAD.

Source of infection

  • Increases in community transmission reduced the ability of PHUs to accurately report place of acquisition. From 13 December 2021, the source of infection is not reported.

References

  1. The Kirby Institute. 2023. Seroprevalence of SARS-CoV-2-specific antibodies among Australian blood donors: Supplementary materials. Kensington.
  2. Australian Bureau of Statistics. 2023. COVID-19 mortality in Australia: deaths registered until 31 January 2023. Canberra.
  3. Communicable Diseases Network Australia. 2022. Coronavirus Disease 2019 (COVID-19) CDNA national guidelines for public health units. Australian Government. Accessed 22 November 2022.
  4. Actuaries Institute Australia COVID-19 Mortality Working Group analysis of excess deaths Almost 20,000 excess deaths for 2022 in Australia - Actuaries Digital - Almost 20,000 excess deaths for 2022 in Australia | Actuaries Digital Accessed 16 March 2023.
  5. Abu TZ, Elliott SJ. 2022. The critical need for WASH in emergency preparedness in health settings, the case of COVID-19 pandemic in Kisumu Kenya. Health Place. 76:102841. doi:10.1016/j.healthplace.2022.102841
  6. Healey Q, Sheikh A, Daines L, Vasileiou E. 2022. Symptoms and signs of long COVID: A rapid review and meta-analysis. Accessed 10 November 2022.

Last updated: March 2023