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Coronavirus – the Anopheles 747 – March 15

Of the 197 cases of  Covid-19 virus infection in Australia, 130 are directly related to international air travel.

30 have been caught “on the ground” from other people with the infection, and about 30 are yet to be determined. My suspicion is many of these “unknowns” represent contacts from people who have flown and had a mild episode, so the international air and sea travel is likely responsible for over 80% of cases currently.

The next three weeks are critical. If the numbers increase exponentially as they have in Italy, in three months’ time we could peak at 30,000 people having had the infection and 3,000 having needed Intensive Care Units because of Acute Respiratory Distress syndrome.

 

Here are the projections for Italy from the Lancet article by Remuzzi and Remuzzi. They are modelled on the success of strict lock-down in Hubei province in China. Our population is about half and if we experience the same exponential growth in numbers as they did, we will hit a peak of about 30,000 in 3 months time before our weekly numbers drop enough to have the total look more like a plateau as a result of a lock-down.. We don’t really want to wait until we need lock-down.

We will then be at risk of another outbreak in 2021.  The virus has come into being in the last year. A new species that accidentally has the ability to feed off the plague of Homo sapiens infesting the planet. So. Pockets of the virus will live on here and there waiting for the right conditions.. e.g. winter. We will immunize against it and largely eliminate it, but will it evolve?

So far, since mid January we have had a constant infusion of people bringing the virus here from overseas – 150 plus cases spread over 9 weeks. But our Federal Government has been listening to the Accountancy argument – not the Medical argument.

The Accountancy (short term) argument is to sit tight and run the gamble that the pandemic will settle elsewhere and finally stop coming here.

It won’t.

Even today I have heard of yet another international relative visiting a family here and testing positive. We still have excessive delays in diagnosis that mean we will find out about our own epidemic 3-7  days late. We need more drive-through testing availability. Waiting from Friday to Tuesday to get a test done isn’t good enough.

 

So, like malaria, we have to treat the carrier – the vector – of the disease, because we can’t treat the disease.

With malaria that meant draining the swamps and killing the vector.

With Covid-19 that means restricting casual travel internationally. Enforcing 2 weeks self isolation after returning internationally by plane or boat…..

 

The Prime Minister of New Zealand has acted already. That’s leadership. ScoMo has followed the trend.  (3 pm 15th March)

 

We are at a cross-roads – in NSW in particular, where there have been 100 cases and the epidemic could take off any day now. Then the numbers estimated above will become the minimum Australian figures for this season.

The critical issue is Federal and State proactivity, rather than reactivity.

 

So why are we worrying about a virus that barely affects the young and healthy and with 80% of them getting a “cold” only?

It’s because 30,000 cases in Australia could double every 2 weeks until we hit the millions and then it could come back the next winter for another go at us. The strain on the health system will be enormous.

The new species is already proving to be very successful. It is achieving in weeks what the 1918 “Spanish” flu took years to achieve because it uses its host to achieve high speed international travel.

If it proves to be moderately successful at producing mutations each year it can keep us challenged for decades.

By comparison the influenza virus produces about 250,000 cases a year, is spread over 4 months, and has a much lower average death rate.

It mutates periodically and survives in large part by being protected within the non-immunising community.

Last time it had a major mutation (2009) it probably caused 500,000 episodes of the flu that year. This was despite good Immunisation coverage in the over 65’s and about half of those in the health industry being immunised. Almost no-one in Australia has immunity to Covid-19.

So the potential for very large numbers of Covid-19 infections remains for this year. The focus for now needs to be on stopping the imported Covid-19 carriers from handing it on.

Whenever a single carrier is identified, the measures to trace potential recipients of that infection need to be intense.

My advice to you at the moment is to remember that this is a sticky persistent virus. If it is anywhere near you, step back far enough and long enough. It’s not a big risk to a young family, but it becomes a bigger risk if it gets handed on. The goal for SA for now is to flatten the curve sufficiently that we do not get significant transmission from non-travelers to non-travelers.(phase two – as in Italy)

And, of course, we need to stop the importation of the virus, and that can be largely achieved by 2 weeks of mandatory self isolation of all people coming to Australia. This is phase one of our defense. Phase two – person to person on-land transmission is much harder to control, as has been the case in Italy, but we don’t have to get that far this year if we manage phase one well. We may remain at phase one for several years.

Terry