Decline in COVID-19 testing casts doubt on claims Australia is “flattening the curve”

By Martin Scott
9 April 2020

To date, 51 Australians have died from COVID-19, and the death of three South Australians this week means that the Northern Territory is the only region yet to have recorded a fatal case.

Despite government claims that Australia’s tough social-distancing measures are beginning to reduce the incidence of new confirmed cases, the official total is over 6,000 and rising. The real number is almost certainly far higher.

As is the case globally, testing for COVID-19 in Australia has been limited. To date, fewer than 330,000 tests have been carried out in a country with a population of more than 25 million.

The total number of confirmed cases in Australia has increased at a similar rate to the number of tests

Patients presenting with fever or respiratory symptoms in Australia are only tested for COVID-19 if they have recently travelled overseas or have had known contact with a confirmed case or local cluster. Since March 25, all health and aged care workers with coronavirus symptoms have also been eligible to undergo tests.

Across the country, just 8,038 COVID-19 tests were carried out on Tuesday, the second lowest number in the last week, and less than half the number carried out on March 29. This is despite claims by state health authorities that they are broadening the scope of testing.

The small number of COVID-19 tests conducted throughout Australia, and the highly selective basis upon which they continue to be conducted means that it is impossible to draw statistically meaningful conclusions from the results of these tests. One thing that is consistently shown by the data is that the number of confirmed cases is directly dependent on the number of tests carried out.

While tests conducted over the past week have shown a decline in the percentage of tests returning positive results, Monday’s positive rate of 2 percent is higher than the overall figure of 1.9 percent since testing began. In other words, there is no indication that the incidence of COVID-19 is decreasing.

The low rate of testing means that the daily figures are easily skewed by variations in the number of tests conducted in different locations.

In NSW, where 40 percent of tests have been conducted, the cumulative percentage of positive tests has steadily increased from 0.5 percent on March 8 to 2.13 percent on April 7, still lower than the positive rate on any individual day since March 22. Of the 2,108 tests reported on Tuesday in NSW, 49 returned positive results, a higher rate than the previous two days.

New confirmed cases in NSW have moved in lockstep with the reduction in new tests

Prime Minister Scott Morrison and Chief Medical Officer Brendan Murphy yesterday held a press conference at which they unveiled modelling funded by the government and carried out by the Doherty Institute.

This modelling, based on overseas data, predicted that if no quarantine, isolation, or social distancing measures were carried out, 89 percent of the population would become infected, nearly 1.4 million would require hospitalisation, and more than 400,000 would need to be admitted to the Intensive Care Unit (ICU).

Australia currently has a total of 2,229 ICU beds, and the modelling assumes that half of these would be required for cases unrelated to COVID-19.

Taking into account the strictest social distancing measures considered in the model, under which 11.6 percent of the population is expected to be infected, the number of ICU beds available for COVID-19 patients will need to be tripled before there is a reasonable likelihood of meeting the demand.

The report raised the need for strict enforcement of social distancing measures, including through “proxy indicators of compliance such as transport and mobile phone data,” providing the justification for increased surveillance and erosion of democratic rights.

Not considered in the model were “health care worker absenteeism due to illness, carer responsibilities or burnout,” or “shortages in critical medical supplies.”

Morrison said that, while the model was not based on Australian data, it proved the “theory of flattening the curve,” and that Australia was “on the right track,” as the “daily growth rate in cases has now fallen to just a few percentage points per day.”

The reality is that the reported reduced growth rate has coincided with a decrease in the number of tests being carried out, particularly in NSW and Victoria, which have the highest number of confirmed cases.

The daily positive test rate in NSW remains higher than the cumulative rate

Morrison’s claim that “less than 10 percent” of confirmed cases have resulted from community transmission is entirely speculative, given that testing for COVID-19 in Australia has mostly been limited to those patients who have recently travelled overseas, or who have been in close contact with people who had done so.

This has been justified by federal and state governments on the basis that most of the confirmed cases had resulted from such circumstances. In fact, this is a self-fulfilling prophecy: if the vast majority of test subjects have travelled overseas, then the majority of confirmed cases will inevitably be in patients who have travelled overseas.

Due to the testing criteria, locally-acquired COVID-19 cases have only been counted in the official figures when they have been severe enough to require hospitalisation.

As of Sunday, more than 15 percent of the 2,640 confirmed cases in NSW were contracted locally, by people with no known links to other confirmed cases, geographical hot spots, or recently returned international travellers. On March 24, this was true in only 9 percent of confirmed cases in the state.

Since the first Australian cases of COVID-19 were discovered in January, all levels of government have insisted that recent international travel was the single most important risk factor for contracting the virus. Certainly, in the beginning, that was rational, but the failure to systematically test or quarantine returning travellers has allowed infection to spread throughout the community.

Incoming passenger screening was introduced at Australian airports on February 2, but limited to travellers arriving from “high-risk” countries. Temperature checks for all arriving passengers were not introduced until March 26. In any case, as the Doherty modelling documents make clear, testing for fever is of limited use in detecting COVID-19 because of the long incubation period of the virus before symptoms develop.

There have been reports that health workers conducting the temperature checks have received minimal training in the safety precautions necessary during a pandemic. This, coupled with the cramped conditions in airport arrival halls, has likely resulted in increased transmission of the virus.

Mandatory quarantine for international arrivals was not introduced until March 28. Prior to that, people arriving from overseas were required to self-isolate, but, as no special ground transportation was provided, many incoming passengers were forced on to public transport, potentially exposing large numbers of people to the virus.

Data from Iceland, the country with by far the highest rate of testing, has shown that up to 50 percent of those infected with COVID-19 show no symptoms, yet there have been no moves in Australia to institute random testing to ascertain the true spread of the virus. Asked whether any such move was planned, Morrison said that testing resources were “finite,” and needed to be rationed, while Murphy claimed without any substantiation “there isn’t a lot of evidence about it.”

The introduction of police-enforced bans on “gatherings” of more than two people across most of the country demonstrates that Australian governments and health authorities are in fact keenly aware of the risk of community transmission through asymptomatic carriers. They have used the results of the extremely limited and biased testing to play down the danger and insist that workers in education, childcare, construction, retail, manufacturing, and other industries continue to go to work as usual.