EXPERT REACTION: Victoria's jump in COVID-19 cases - is this a second wave?

Pooled testing makes sense statistically if the disease prevalence is low, which is the case in Australia at the moment. Pooled testing can protect Australia from a second wave of COVID-19 infection by eliminating the threat of asymptomatic spread and super-spreaders, and allowing “targeted” quarantine.

The only affordable testing approach for Australia to avoid a second wave of infection is “pooled testing”. As the name suggests, pooled testing is the pooling together of a group of samples to run only one test . For example, every week all households in one street collect their own samples of saliva and deposit them in a testing bin. The lab then combines together all the saliva samples from one street, or even one suburb, into a single sample for testing. In this way the number of tests required can be reduced by a factor of 10 or more. The group sizes can be adjusted to any number to accommodate any population size and any budget.

I think this is clearly a second wave – the question is whether it is a ripple or the start of a tsunami. Certainly, the rise in daily reported cases looks qualitatively very similar to the initial wave in March. However, this does need to be viewed in terms of the increased testing and relaxation of the criteria for testing. We will be seeing more asymptomatic cases amongst these positives than was the case back in March. Victoria's percentage of positive tests is now less than 0.5 per cent, whereas it was about 2 per cent in mid-March.

My suspicion is that Victoria has just been rather unlucky – obviously, one will expect more such outbreaks in the most populous states, but one of the features of the exponential growth that can follow an initial case in the general community is that it can rapidly lead to a large number of total cases. There have probably been lots of other transmission events into the general community from returning travellers that have never been detected and have not led to long chains of transmission.

Victoria needs to stamp out these emerging spikes as quickly as possible. In addition to the increased testing, I think there is a case to lockdown the hotspot suburbs. This is surely likely to lead to Queensland in particular reassessing whether to open the borders to Victoria and New South Wales.

Q. Is this a second wave?

"This is not unexpected, as health authorities have been warning of the possibility of a second wave of infections, as the same is happening in the US and Europe after easing the lockdown restrictions. People coming out of long weeks of lock down are forgetting that the virus still exists in the community and the fact that not every infected person will have symptoms. Therefore, the ignorance to continue practising social distancing in general and physical distancing between family members and friends, have led to the surge in cases. Due to the cold weather in Victoria, most people are gathering inside, in closed spaces rather than outside, which increase the possibility of infections. Furthermore, in the last few days, more than 53,000 COVID-19 tests were conducted with a focus on hot spot suburbs, and with the large number of tests, it is normal that more cases (mainly from asymptomatic carriers) will be detected, and that is good as it is identifying the most serious transmitters within the community."

Q. Why is this happening in Victoria and not other states?

"The issue with training and COVID awareness amongst quarantine hotels security guards and probably the cleaners, was a main factor that led to the spread of cases from quarantined travellers to workers and then to their families. These community transmitted cases increased between socially connected large families and became an important factor contributing the surge in positive cases after easing of restrictions, and due to the cold weather in Victoria where people are getting together and staying for a long time to in closed spaces.

The recent change in conditions for testing quarantined travellers and the availability of the new saliva testing kits for children and vulnerable people will hopefully contribute to detect more cases and the control of spreading infections."

Q. Do Victoria need to return to lockdown?

"It is necessary to control this community transmitted cases, and if needed, a return to lockdown should come sooner than later." 

Q. Should states reconsider the re-opening of borders?

"This should not impact on the rest of the country, mainly where borders are still closed between Victoria and most of the States. These boarders may stay closed for now until the cases in Victoria are under control.

I believe better communication methods with non-English speaking communities, and the younger Victorians (given that higher rates of infections have been detected in younger Victorians mainly the 20-30 years of age) using social media platforms, with information in different languages about the high infectious rate of this virus, and the possibility of young asymptomatic carries transmitting it to their older family members, are important messages to the community to control the spread of COVID-19 cases.

This is a reminder of just how difficult it can be to detect cases.  Victoria has been doing a great job and yet there has been a quiet outbreak afoot that has only just come to light over the last few days.  It is absolutely critical that anyone with even the mildest symptoms should present themselves for testing.  I know it might feel like a drag to go and get tested, but not doing so puts the entire community at risk. 

For anyone wanting to see the latest estimate of undiagnosed cases in the State: http://au.covid19forecast.science.unimelb.edu.au/.

The rapidly growing outbreaks in Melbourne are concerning and a stark reminder that we have not eliminated SARS-CoV-2 from Australia. The difficulty with controlling this virus comes from its ability to be transmitted before people start showing symptoms, if indeed they show symptoms at all. There are a number of scientific reports now about asymptomatic transmission of SARS-CoV-2, and the rate varies from study to study (average is approx. 20 per cent https://www.cebm.net/covid-19/covid-19-what-proportion-are-asymptomatic/).

I believe we can still control these outbreaks and prevent a second wave of COVID-19, using the thorough testing and contact tracing methods that have been implemented, and strict measures to ensure compliance with isolation and quarantine. As we go forward, we need to maintain 1.5m physical distancing measures (even when catching up with friends and family), regular handwashing with soap and water (or hand sanitiser if not available), keep the COVIDsafe app open and importantly - stay home if you are sick. These outbreaks are something that we will have to deal with regularly until we develop a safe and effective vaccine for SARS-CoV-2, which could be a year or more away.

Q. Is this a second wave?

"This is a resurgence of epic proportion that can be truly appreciated when a rolling 14 day average (twice the average incubation period) is examined that shows clearly incremental increases then a sharp doubling."

Q. Why is this happening in Victoria and not other states? Is this something they did or didn’t do?

"Victoria has had three distinct risk categories – community that is mostly family clusters, quarantine hotel staff, and health providers and these could happen in NSW but what is particularly driving this is the interconnection between these three risk groups. Australia is a country of migrants and we embrace our cultural communities so the authorities need to work proactively with communities with English as an additional language who may not hear or read the messaging in English about the importance of responding to feeling unwell and keeping visitors to a minimum."

Q. Do Victoria need to return to lockdown?

"Yes in the hotspots but this needs to be in addition to requesting those in the ‘lock down’ areas (otherwise known as ring fencing) with instructions to wear a mask to the shops and when exercising, and messaging to all other Victorian regions to not go to work sick and wear a mask in public transport."

Will this impact the rest of the country – ie should states reconsider the re-opening of borders?

"Reopening the borders except to the hotspots."

Q. Anything else?

"It’s time the Authorities accepted the WHO Mask Guidelines for people living in areas with high infection and those who find themselves in situations where they cannot keep physical distancing such as in public transport and hotspots. The messaging that masks only work by protecting uninfected persons from an infected person who is wearing the mask is not correct - otherwise why do health workers wear a mask while carrying for someone with COVID? New evidence suggests recently developed reusable cloth masks can provide up to 70% protection and the Australian public can be educated about how to care for a reusable mask while undertaking the other elements of the COVID prevention strategies (hand hygiene, social distancing and getting tested if felling unwell).

Experience in other countries such as Singapore or Korea has shown that the novel coronavirus will exploit any weakness in the public health system. Victoria’s weakness appears to have been “leakage” from quarantine, whereby quarantine hotel workers were not adequately trained in infection prevention and the quarantined travellers were not “cleared” prior to release. This weakness, coupled with community complacency, has led to further spread in the community. For other states, this underscores the importance of quarantine of travellers with strong training for those involved at the quarantine hotels.

Q. Is this a second wave?

"There is no formal definition of second wave, so it is a subjective assessment. This is a resurgence following a period of suppression, which has followed the resumption of social activities. As we resume interactions and contact with other people, the risk of infection will increase, everywhere in Australia. This tells us there is silent transmission. The scientific evidence from numerous studies shows an important role of spread of COVID-19 from people who do not have symptoms. The WHO and many countries have been slow and reluctant to accept the overwhelming evidence of this. Until we do, and act accordingly, there will be more preventable outbreaks."

Q. Why is this happening in Victoria and not other states? Is this something they did or didn’t do?

"This could happen in any part of Australia, and probably will, over the next year or so. The pandemic is getting worse globally, and we do not yet have an effective vaccine."

Q. Does Victoria need to return to lockdown?

"This is a matter for Victorian authorities, but geographically targeted lockdowns were effective in South Korea, so could be considered. Face masks are also a no-brainer that could reduce the need for more restrictive measures. We need to use everything available, and stop the confused and negative messaging about masks. Masks work. They are cheap and effective. They do NOT increase risky behaviour or make people forget to wash their hands, as some people suggest - there is no scientific evidence to support this. In fact, the real-world evidence is the opposite - that masks reduce the risk by 85%. So let’s start some positive messaging and give people advice on how to make their own mask and how to use masks."

Q. Will this impact the rest of the country – ie should states reconsider the re-opening of borders?

"We all need to realise the gravity of the pandemic, and not go into denial and ignore public health advice. We are one of the few countries in the world to control and suppress COVID-19 - we could lose those hard-won gains if people become complacent. We need a social contract between the government and the people - where in exchange for freedom to do the things we want to do, in return we maintain physical distancing, wear a mask and download the COVID-Safe App. The downloads of the App are nowhere near enough for it to be effective, and this is a critical time during which it could make the difference between losing control and not.

Q. Anything else?

"The two major factors which make this infection so hard to control are:

1. asymptomatic transmission - you cannot identify everyone who is infected, and may not even know if you are infected. Until testing of every at-risk person during outbreaks is conducted, asymptomatic cases will be missed and outbreaks will occur.
2. SARS-CoV-2 can be spread by the airborne route - numerous studies confirm this, and one study shows it is more airborne than SARS or MERS. That same study showed viable virus in the air 16 hours after it was aerosolised. The denial of the evidence which we see by WHO and many countries will come at a cost, and result in preventable outbreaks.  The air we breathe matters as much as what we touch and who sneezes in our face.

What individuals can do to help control this virus, in the absence of a vaccine, is physical distancing, which has been shown to protect; face masks, also shown to protect; and downloading the App.  Without a social contract where people play their part in helping, the testing and tracing strategy will not be enough on it’s own.

With the massive amount of testing in various Melbourne suburbs, it was expected that more cases would be found. However, 23 of the 70 newly diagnosed cases are potentially community-acquired, meaning that the authorities do not have a handle on where the infection came from. This is of major concern. 

The Victorian Government with the assistance of staff from other states and the ADF have put enormous resources into testing, contact tracing and providing information in different languages in the affected suburbs. However, the outbreak has the potential to rapidly escalate, and for the public health authority to lose control of the outbreak. Perhaps it is time for testing to be made mandatory, and for all residents in the affected areas to be tested.

The rise in cases is a concern and the current level of lock down and social distancing may need to be reconsidered.

The current spike in cases in Victoria is not a second wave of the pandemic. There are cases in returned overseas travellers and cases related to chains established before the increase in testing that started late last week. What we are seeing is this increased testing identifying cases that otherwise may have been missed. Some of these are linked to established chains of infection and others may well be added to these chains as contact tracing progresses.

Why this is happening in Victoria is likely to be multifaceted. We know that respiratory viruses spread well during winter due to people being in close proximity inside with limited natural ventilation. This combined with the expected increase in cases as restrictions were eased is likely the main reason there is a Victorian focus, however, other jurisdictions should not be complacent. Victoria has implemented a world leading response to this spike, it is highly resource intensive but it is uncovering new cases and allowing these to be identified and contained. This is the intent of the testing program. It will take time for these numbers to come down. It appears that the current spike in cases is not leading to increases in hospitalisations at this time, indicating that these are mild infections and are ones that need to be identified and isolated to reduce further transmission.

Victoria may need to return to tighter restrictions including locking down. Potentially this may include local lock downs based on suburb however these would be difficult to enforce. That said regional tightening of restrictions on areas greater than suburbs would be possible and more economically viable than shutting down the whole state. Other jurisdictions should be learning from this situation in Victoria as it is possible for spikes to occur elsewhere in Australia. Border closures have proven useful and should be carefully considered by those jurisdictions that have open travel with Victoria. As always any restrictions imposed to reduce the spread of disease does have social and economic consequences and the Premiers with their Health teams have to weigh up all of these in their response.

The message to the community remains: Hand hygiene, cover your cough, get tested if unwell, stay at home if unwell and if you are in a location of increased infection limit your interactions outside of your home to necessity only.

Teens and young adults should be proud to know that they are essential in protecting the health of their more vulnerable friends, neighbours and family. They are really on the frontlines of this crisis, while our healthcare workers are actually the last line of defence. We think that young people have an important role to play in understanding and communicating about COVID-19 with their friends and families about the risks from the virus. They are more than capable of abiding by the physical distancing and hygiene guidelines needed to keep our entire community safe.

The increased number of cases in cases in Victoria are alarming, but this doesn’t mean that it’s the start of something bigger, or the so called second wave.  Fortunately the active cases have been identified, and this will help lessen the impact of further infections. More than likely what is being observed is the result of increased community testing and contact tracing, the more we test the more that we are likely to find positive cases.  This does mean that we all have to be vigilant and maintain good hygiene and physical (social) distancing. I think that we need to applaud the Victorian health system for putting a number of measures in place quickly to stop the further spread of the virus.

It is likely that more cases will be found, but I hope that this is just a minor blip in efforts to control the virus.  If we go into total isolation we could effectively stop all virus transmission, but total isolation is an extreme measure and not sustainable for the long term. Localised outbreaks such as these are likely to occur again, but we can learn from them to make the impact of future outbreaks less.

Q. Is this a second wave?

"In terms of Australia’s experience, this is evidence of a second wave in that 75 new cases in Victoria is similar to that experienced in the first wave in Victoria. However, it is important to keep this in perspective, in that while Australia detected 75 new cases in the last 24 hours, the United States diagnosed over 44,000 new cases and Brazil almost 47,000 new cases. Thus, while there is evidence of community transmission occurring in Victoria it is not as yet widespread.

The importance of this difference is that the principal strategy remains, to identify all cases to require them and their contacts to be isolated, and to closely monitor the contacts to identify any emergence of symptoms and to ensure that those people are tested as well." 

Q. Why is this happening in Victoria and not other states? Is this something they did or didn’t do?

"There is no specific reason why this could be happening in Victoria and not in other states. Victoria instituted the same policies at the same time if not earlier, in terms of restricted movement social interaction and enhanced personal hygiene. Additionally, there has been an extensive testing regime in Victoria and the proportion of people tested is similar to other states if not more.

Beyond these considerations of management strategies, there has been considerable speculation in terms of social and behavioural issues or characteristics of Victorians which are speculative at best. This would require much greater analysis before determining that they have been of influence." 

Q. Does Victoria need to return to lockdown?

"It would be wise for Victoria to again increase social distancing and reemphasise enhanced personal hygiene. The principal strategy to control the outbreak in Victoria at this stage remains case identification, contact tracing, isolation/quarantine and close monitoring. However the effectiveness of these strategies would be enhanced by breaking the rate of growth of the outbreak and the spread around other communities. This would be best achieved by enhanced social distancing particularly for those who have symptoms that may be suspicious of COVID 19."

Q. Will this impact the rest of the country – ie should states reconsider the re-opening of borders?

"The situation Victoria is of considerable concern to the other states and territories in which there has been very little evidence of sustained community transmission for a number of weeks. The only new cases in those states are amongst those people who have acquired the disease overseas and have returned to Australia. As they have been in quarantine, they pose little risk to the broader Australian community.
It would be in no one’s interest for undetected disease amongst people in Victoria to spread to other states and cause further community-based outbreaks in those states."

Q. Anything else?

"Australia’s response has been the envy of much of the world and is currently at risk because of what is happening in Victoria. If Australia had the mortality of New York City we would have had more than 60,000 deaths. It is critical that the situation in Victoria is brought under control as quickly as possible.
The extensive testing occurring in Victoria is important to find as many cases as possible. If this is “flushing out” those responsible for spreading the disease, then the numbers being detected is promising but it would be important to see these number begin to fall.