Pandemic influenza testing at the coalface: time for reassessment?

To the Editor: In their recent article, Beaman and Leung raised a number of important and pertinent issues about what we can learn from the influenza pandemic of 2009.1 However, we would like to correct a number of misconceptions on their part, including claims that Western Australia’s central public reference laboratory, PathWest Laboratory Medicine WA, (i) unreasonably favoured polymerase chain reaction (PCR) testing over antigen testing; (ii) rationed and prioritised testing primarily because of inability to cope with the high demand; (iii) rarely achieved the benchmark turnaround time of 48 hours; and (iv) spent excessive time processing a large number of specimens, of which 96% were reported as negative.

State reference laboratories had to provide tests that would best guide individual patient management and the most effective use of hospital beds, as well as informing the public health response. The decision to avoid antigen detection tests was supported by the World Health Organization from the beginning of the pandemic2 and confirmed by subsequent published data showing that PCR testing was more reliable than antigen testing.3,4 Inaccurate test results hinder rather than help the pandemic response,5 especially in the early stages.

From very early in the pandemic, we prioritised samples from hospitalised patients, health care workers, people at higher risk of severe disease and cases of special public health importance. For these urgent samples we aimed for, and largely achieved, a 48-hour turnaround time. Beaman and Leung did not allow for the substantial delays in transport and processing of samples before testing, which contributed 2–3 days to the turnaround time. A similar experience was reported in Victoria.6 This has highlighted the need to improve the way in which samples are handled at all stages between collection and testing.

Rationing of services was a decision made in consultation with our public health colleagues, to ensure sustainable testing capacity for essential clinical and public health needs. In the end, PathWest tested 24 310 samples, representing 92.8% of the samples received, which included all of the high-priority and/or critical samples.

It is misleading to suggest that a 96% negative rate was inefficient, and is a misunderstanding of the purpose of testing in the different phases of the pandemic. In the early phases, the yield of positive test results was expected to be low, as there was active case-finding at a time when no or very little virus was present in Australia. Across the course of the pandemic, the positive rate at our laboratory was 23% overall and 40% during the peak week.

The response of public and private laboratories to the pandemic throughout Australia was impressive, and has now been the subject of state and national debriefings to identify potential improvements and the highest priorities for action. As part of that, we should all look at how we could improve our own laboratory’s performance and how we could make the best contribution to dealing with future pandemics and other emerging infectious diseases, both as individuals and as members of organisations.

We would like to take this opportunity to acknowledge all the people within and outside laboratories who made a huge effort to save lives and reduce the impact of the pandemic.