Yes, it looks like Victoria has passed the peak of its second wave. It probably did earlier than we think

Ian Marschner, University of Sydney

It’s hard to recall a time when we didn’t nervously await the announcement of Victoria’s daily COVID-19 case numbers each morning.

It was certainly disconcerting when the state recorded more than 700 new cases on two occasions not long ago.

And likewise, now that we’ve seen a few consecutive days of around 300-400 cases, it’s tempting to ask whether the peak of Victoria’s second wave is behind us.

The good news is, current daily case numbers do indicate we’ve passed the peak of the second wave. But I would suggest we actually reached the peak at the end of July, and the reported case numbers are only now catching up.

Daily case numbers versus new infections

Before we can answer the question of whether Victoria has passed the peak of its second wave, we need to be clear about what we’re asking. Although it’s natural to focus on the reported case numbers because they’re highly visible, the outbreak’s progress is in fact driven by the number of new infections.

COVID-19 infections can take up to two weeks to be diagnosed and appear in the official case count. This is because an infected person must first pass through an incubation period (the time between becoming infected and symptoms presenting), and then be tested and wait for their result.

On average, the process takes about one week, but it can vary substantially from person to person.

Read more:
Two weeks of mandatory masks, but a record 725 new cases: why are Melbourne’s COVID-19 numbers so stubbornly high?

So today’s case numbers — rather than indicating new infections — actually reflect infections that occurred up to two weeks ago.

In other words, watching the case numbers doesn’t tell us the full story about the current spread of the virus. When asking whether we’ve passed the peak, we really need to focus on the peak in daily infections.

That’s where data analytics come in

We don’t know how many new infections occur each day because infections remain hidden until symptoms develop or there’s some other reason for a person to get tested.

But we do have a good idea of how long it takes for someone to progress from infection to symptoms, and then from symptoms to diagnosis by a positive test.

By combining the observed case numbers with a mathematical model for the progress from infection to diagnosis, we can then reconstruct the pattern of past infections that would have led to the case numbers. This is an epidemiological analysis method called back-projection.

This analysis is an estimate, not an observation. But we can use it to explore whether there’s any evidence infection numbers have peaked, and at what point.

Looking back to the first wave

Earlier in the outbreak I used this approach to evaluate the effectiveness of the government’s control measures. In a study looking at the first wave of infections across Australia, I showed that the timing of government restrictions matched almost exactly with the flattening and downturn of infection numbers.

This was despite the fact case numbers continued to rise after restrictions were introduced. In other words, the case numbers were hiding the good progress that was going on in the background.

Read more:
Takeaway coffee allowed, but no wandering through Bunnings: here’s why Melbourne’s new business restrictions will reduce cases

By clamping down early, we probably avoided tens of thousands of infections nationally. A recent study published in the Medical Journal of Australia estimated Victoria’s control measures averted between 9,000 and 37,000 cases in July.

Returning to Victoria’s second wave

We can use the same data analytics approach to explore the progress of the recent restrictions in controlling Victoria’s second wave.

My reconstruction of Victoria’s infection numbers during the second wave, shown below, illustrates an early rise in infections during June. This rise likely accelerated in the first half of July, when new infections would have been increasing at a substantially greater rate than was evident in the daily case numbers.

This lag in the case numbers makes it plausible the recent flattening of daily cases is being driven by a much more pronounced decrease in the underlying infection numbers. This is what the reconstructed infection numbers are suggesting in the graph, which shows a peak in late July.

Again, this is an estimate rather than an observation, and the very recent infection numbers have considerable uncertainty. (This is because we work backwards with this analysis, and very few of the most recent infections will have shown up yet in the case numbers.)

Room for optimism, but not complacency

The lower case numbers in recent days suggest we’ve reached and passed the peak of Victoria’s second wave, and my analysis strengthens and supports this. It shows a peak and decline in new infections over the last couple of weeks.

If this is true there’s good reason to be optimistic the tough restrictions will drive the infection curve, and subsequently the case numbers, down even further.

But it’s sobering that my same analyses estimate Victoria has had about 2,000 more infections than case diagnoses. That’s an estimated 2,000 people who are infected but don’t yet know it.

So even if new infections have peaked, as we all hope, there’s plenty of potential for the curve to turn back up again if adherence to the restrictions wavers. Victorians have some reason to be optimistic that the peak has passed, but there’s no room for complacency.

Read more:
Got a COVID-19 test in Victoria and still haven’t got your results? Here’s what may be happening — and what to do

The Conversation

Ian Marschner, Professor of Biostatistics, NHMRC Clinical Trials Centre, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The ‘dreaded duo’: Australia will likely hit a peak in coronavirus cases around flu season


C Raina MacIntyre, UNSW

The prime minister earlier today announced that from May 1, people need to be vaccinated against the flu before visiting an aged care facility.

The idea is to limit the risk of the “dreaded duo” of respiratory diseases – influenza and coronavirus – affecting the frail and elderly.

We’re concerned about the combined impact of the flu and the coronavirus on us and our health system. But we can minimise that impact.

Sign up to The Conversation

Coronavirus peak set for flu season

The peak of COVID-19 cases in Australia is yet to come, with estimates numbers will double about every three to six days.

This exponential rise means Australia’s peak in COVID-19 cases may converge with our annual influenza season, which peaks on average in August each year.

Both influenza and coronavirus can cause severe illness, but the coronavirus is about ten times more deadly than the flu.

Both viruses cause severe pneumonia, so getting them together could be a serious blow to the lungs.

Severe infection with either virus can result in pneumonia and respiratory failure requiring mechanical ventilation, or even ECMO, a method of oxygenating the blood outside the body.

Read more:
How does coronavirus kill?

Infection with either virus affects older people and people with chronic diseases more severely, which makes these the highest risk groups for being infected with both viruses at once. People in aged care facilities are particularly at risk.

Influenza can severely affect infants and children under five years old.

We do not have as much information about COVID-19 in children, which may cause mild or no symptoms. But a new study suggests it can be severe in 6% of kids, especially those under five years. A 14-year-old child in China has also died.

Co-infection with influenza has been documented in China. In one study, 34% of over 8,000 fever patients who were tested had COVID-19, and less than 1% were infected with COVID-19 and another virus, including influenza.

Health systems will be under more strain

Another impact of influenza and COVID-19 circulating simultaneously is on our health systems.

Every winter, we need to have extra hospital beds and staff to cope with influenza. However, for COVID-19, we will need to plan for more, as death rates, hospitalisation rates and ICU admission rates are higher.

So a severe epidemic of COVID-19 during our influenza season could result in a severely overloaded health system unable to cope, as we are seeing in Italy.

Read more:
Italy’s ‘darkest hour’: how coronavirus became a very political problem

What can we do? Get the flu vaccine

We do not have a vaccine for COVID-19 yet, but we do have vaccines to protect against influenza.

So, if you’re at increased risk for influenza complications, make sure you’re vaccinated.

Influenza vaccination is recommended and funded in Australia for risk groups, such as people aged 65 years and over, people with chronic conditions such as heart, lung or neurological diseases, pregnant women, and for children six months to under five years old.

Flu vaccine is also recommended, but not funded, for people aged five to 65 years. Carers of vulnerable people, and people who work in health care, childcare or aged care should also get vaccinated.

Read more:
You can’t get influenza from a flu shot – here’s how it works

Now that influenza vaccination is already available this season in pharmacies, it’s fast and convenient for busy working people to get vaccinated.

People at risk can be vaccinated any time from March to May. There is some evidence that flu vaccine immunity does not last a full 12 months, but timing of vaccination makes only a small difference to preventing influenza.

So if you forget to get the flu vaccine, it is still worth getting vaccinated any time later in the year.

What else can we do?

Both influenza and COVID-19 can be transmitted before symptoms occur or by people with no symptoms.

So to reduce the risk of transmission of either virus, the World Health Organisation recommends washing your hands frequently, coughing into your elbow, and cleaning and disinfecting frequently touched objects.

Indian cricket legend Sachin Tendulkar shows how to wash you hands properly.

Social distancing – such as maintaining spatial separation from other people, avoiding crowds, working from home – will also reduce the risk of both infections.

The more of these measures we use, combined with isolating sick people and quarantining their contacts, the more we can flatten the curve, to reduce the impact of both infectious diseases on individuals and the health system.

Older people and people with chronic diseases especially need to practice social distancing, and avoid unnecessary contact and travel.

We may even need to screen visitors to the home and ask them not to come if ill, especially if there are people at risk in the household.

Younger people, especially those living with older people, should be mindful of avoiding crowds and bringing infection into the household.

Aged care facilities will need to restrict visitors, as recommended in the latest health advice.

With winter almost upon us, we must use all these measures to reduce the combined impact of COVID-19 and influenza.The Conversation

C Raina MacIntyre, Professor of Global Biosecurity, NHMRC Principal Research Fellow, Head, Biosecurity Program, Kirby Institute, UNSW

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Massive Dust Storm

I was moving all of my gear out of storage today and found myself immersed in dust and in the midst of a howling gale. It was ferocious to say the least.

The video below is vision of the storm system hitting Broken Hill in the east of New South Wales.


And the footage below is what it was like near where I live. The footage does not show how strong the gale was at its peak.


AUSTRALIA: BUSHFIRE UPDATE – Thursday 12 February 2009

The ‘Australia Unites’ Bushfire Appeal Telethon has just started in Australia on the Nine television network. The first act was Men at Work with ‘Down Under.’

ABOVE: Men at Work – ‘Down Under’

Donations can be made via 1800 811 700 or on the Red Cross web site at:

The Red Cross Bushfire Appeal has already raised over 55 million dollars (AU) for the victims of the bushfire disaster. If you are able to assist please do so. People outside Australia please visit the Red Cross Australia website given above. Thank you for your help – Australia thanks you.

The latest on the bushfire emergency is that weather conditions have eased greatly and the predicted hot weather for this weekend may not eventuate until later on in the week, which should allow fire-fighters to get on top of most of the fires – though it will take several weeks to put them all out.

Reports today indicate that several dozen new fires ignited today, with a major fire on the outskirts of Melbourne at Ivanhoe. The fire-fighters are desperately trying to get this fire under control. Some 30 major bushfires are still burning in Victoria.

An arsonist is now believed responsible for the major bushfire that razed Marysville and caused so many deaths. If anyone has information on any suspicious activity in the bushfire regions please contact crimestoppers on 1800 333. Two people arrested today on suspicion of arson were released without charges being laid – they were not responsible for any arson attacks.

The official death toll figure stands at 181, with a further 80 people considered missing. The death toll may yet peak beyond 300, with the possibility of entire families dying in their homes in some communities.

Police have indicated that the rumour indicating that some further 142 bodies had been recovered was false – it is not known where this rumour originated.


ABOVE: Australian Christian Churches Bushfire Appeal

ABOVE: Amazing images from the bushfires

ABOVE: Australian Army Bushfire Search Task Force in action

ABOVE: A YouTube Jerk!!!