Why has Melbourne initiated a new COVID testing blitz?

After 11 consecutive days of zero new COVID cases to Tuesday 10 November, the Victorian Government has announced a huge new asymptomatic testing blitz of up to 500,000 people.
 
Backed by GPs and top epidemiologists, the ambitious plan is aimed at ensuring there are no hidden pockets of asymptomatic infection, and is tipped to favour less invasive saliva testing to boost numbers.
 
The blitz is anticipated to take place across Melbourne’s northern and western suburbs, which were major hotspots during the second wave.
 
But a local GP has called on the Victorian Department of Health and Human Services (DHHS) to focus messaging on wider community benefits, rather than the impact on individual health, in order to increase testing numbers.
 
It comes as much of Australia is showing signs of complacency as restrictions further relax and the weather improves, with only around half of people with flu-like symptoms now isolating.
 
Victorian Premier Daniel Andrews has also warned that the fight is not over, with the virus still ‘lurking’.
 
Deakin University Chair of Epidemiology Professor Catherine Bennett told newsGP the blitz is designed to ensure there are no asymptomatic people who might be silently carrying the virus. 
 
‘If we look in the last areas we had community transmission and don’t find any further cases with a hard look, a focused blitz, that will be very reassuring,’ she said.
 
‘We are being very cautious and, given the journey Victoria has been on, that’s understandable.
 
‘We want to be sure there aren’t areas where the virus might still be located. We want to be sure that nothing has been missed as we pivot to prevention mode.’
 
The same asymptomatic blitz approach might also be useful in New South Wales, Professor Bennett said.
 
NSW, which accepted a low level of cases as a trade-off for avoiding the type of lockdown seen in Victoria, had its third day in a row with no local new cases to Tuesday 10 November.
 
‘NSW is getting close to shutting this down. Victoria’s lockdown allowed us to rebuild our public health response and suppress the virus. So we’re in a really good place,’ Professor Bennett said.
 
‘NSW has had a recent cluster they haven’t been able to link to known cases. If NSW started doing upstream testing to try and find the source – and did not only PCR tests but blood tests – you can try to establish links to other known cases.
 
‘It’s good to get that level of information. If NSW does that as well as broad testing, and if they extend it to asymptomatic testing, it could really help them see their days of zero cases continue.’
 
Professor Bennett added that the change in seasons is another positive sign.
 
‘Summer is working in our favour. We were battling COVID in the worst of winter in NSW and Victoria, and it wasn’t ideal,’ she said.
 
‘Europe never got it down below 400 cases a day throughout their summer. They were all potential spot fires waiting to take off as people moved indoors.
 
‘We should be concerned for Europe, but we don’t have that same threat here.’


Melbourne’s northern and western suburbs were major hotspots during the second wave in Victoria. (Image: AAP)

Epidemiologist and UNSW Professor Mary-Louise McLaws told newsGP the Victorian approach is a ‘great idea’ that should be considered by NSW as well.  
 
A recent meta-analysis to which Professor McLaws contributed estimates the asymptomatic rate to be around 17% – lower than previous estimates.
 
‘Some might say that’s not overly concerning, but asymptomatic cases still have the ability to transmit the infection,’ she said.
 
‘Doing mass testing to flush out asymptomatic cases is an excellent idea and will provide additional confirmation that Victoria is in a very safe place.   
 
‘This virus is unbelievably clever. It uses all our human foibles, and it also has additional weaponry by spreading using asymptomatic cases.’ 
 
Professor McLaws said that it is no surprise Victoria and NSW have faced the toughest fight against the coronavirus, given their population, high-dense living, work connectivity and the greatest numbers of returning travellers.
 
She said GPs and health authorities should not relax their guard for anyone with even mild symptoms.
 
‘Given the flu has been remarkably low this year, we should be thinking COVID first,’ she said. ‘That’s why we need to take asymptomatic cases really seriously.’
 
GP Dr Hanna El-Khoury, who has diagnosed and treated many COVID patients across Melbourne’s western suburbs, told newsGP that he supports the idea of the blitz. But he has questions regarding its implementation and how the message will be conveyed to people of different backgrounds – especially given the new testing will be for people without symptoms. 
 
He believes health authority assumptions that targeting people from different ethnic backgrounds simply requires translation of existing messages are a misreading of the real issue.
 
‘Most people from different ethnic backgrounds speak English better than anyone. It’s not a question of language, it’s the understanding of culture and the meaning of what they’re doing,’ he said.
 
‘The DHHS thinks the main message is about the seriousness of the infection. But I keep saying to them, for ethnic groups, the community message is much more important than the individual message.
 
‘If you talk about the reasons for the swab being economic, family, and the community – it’s much more appealing.
 
‘For young people who feel it may be less than the common cold, you’re telling them you want to test them even if asymptomatic. They’ll say, why?
 
‘But if you say, “If we want to be able to go to Sydney, to Adelaide, to live without masks, to have more people in the nightclub, we need to target the community”, they can relate to that.’
 
A DHHS spokesperson told newsGP that as movement across Victoria increases, the department will look for opportunities to keep testing rates up.
 
‘We have been working closely with industries, local councils, community health organisations and other bodies to undertake targeted surveillance testing, including 14,000 tests across the food processing industry over the last month,’ the spokesperson said.
 
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