Melbourne’s COVID19 moment of truth

20 Jul

Melbourne’s COVID19 moment of truth

I’ve been watching the global pandemic data accumulate for months now. Like many, I’ve been trying to make sense of trends and patterns. Where is Covid19 having the most impact? Who will be affected? Who is managing it best?

There appear to be increasingly predictable causation branches that can operate independently, but dramatically increase in impact when operating together. If you’ve been watching the pandemic closely, little of this will surprise you. What surprises me, however, is how often the controls that can reduce the risks, and which are readily available, are routinely ignored. The four main causations are:

1.      Age (median age and population over 65)

2.      Population density (total numbers per square kilometre)

3.      Being indoors (add to this the presence of circulating air conditioning and heating)

4.      Movement (virus transportation).

Older median aged populations are far more at risk than younger median aged populations. A higher median age, also typically includes a greater proportion of people in the 65+ year age bracket. This cohort is far more susceptible. Where do older people congregate? Aged care facilities and hospitals are the obvious places. Co-morbidities increase the impact of the virus once affected, but generally, people seem not to be at greater risk of initial infection by having other conditions. People with other health conditions are more likely to tick more of the four causation boxes, so can be simply in the wrong place at the wrong time. That is, they have a higher probability of coming into contact with an asymptomatic spreader.

In Australia, our median age is 37.9 years. This places us 144th out of 235 nations or nation states. The global median is 30.9 years. The global median is lowered due to the African continent having a median age of 19.7 years, across a population of 1.3 billion people. It is, in world terms a remarkably young continental population, which may provide some protection against Covid19. That is to say, the infection rate may be similar to other places, but the fatality rate could be lower. To date, that is exactly what is occurring.

Italy (second oldest global median age at 47.3) is a prime example of the age risk. But that only tells part of the story. It is age, coupled with population density that creates a much bigger risk. Countries where populations live at close quarters are their own high risk. Italy has 60 million people crammed into that boot which covers the same area as Victoria and Tasmania combined. Italian authorities acted quickly when Covid19 was detected, but the combination of age and population density created an infection hothouse.

In Australia, the ACT has the highest population density, but a relatively small population. It also has a median age which is lower than the national median. Tasmania and South Australia are ‘old’ states, with median ages above 40 years, but with tiny population densities. Victoria, on the other hand, has a median age of 37, but a population density almost three times higher than the next most dense state (26 people per square kilometre, followed by NSW with 9.5 people per square kilometre). Victoria’s (read Melbourne’s) population density is growing rapidly and creates a question of the new risks associated with 21st century higher density living.

International studies are demonstrating how the infection spreads indoors at an alarming rate, compared to its relative dissipation outdoors.  This recent article by Helen Thompson in Science News, unpacks studies across several countries and explains the risk of indoor work and dining. The lesson here is simple. Don’t work in office buildings at the moment, if you can work from home. More troubling though, Melbourne prides itself as being Australia’s food and bar capital. When that is combined with its population density and age profile, we have risk factors unrivalled in Australia.

The final risk factor is movement. This can be split into two sub-categories; (i) quarantine restrictions on returning travellers, and (ii) local movement within cities. With respect to returning travellers, Vietnam is the current world champion in managing this. With a population of 97 million, it went into hard lockdown on 23 January (one of the first in the world) and enforced strict quarantine for returning travellers. Over six months, Vietnam had had less than 400 cases and no deaths, which is an extraordinary outcome for a country of such high population density.

Local movement within cities is an unnecessary risk, particularly if basic control measures aren’t in place. We know that people can be infected but asymptomatic. When inconvenience is confused for deprivation of liberty, exacerbated by the stubborn refusal to regularly and thoroughly wash hands, not touch the face, use hand sanitiser and wear a mask, then we actively invite infection. The USA and Brazil are tragic examples of cultures that are literally killing themselves, on the insistence of freedom and individual rights, above caution and collective responsibility.

The lessons for us all in Australia self-evident if we take the time to look. In metropolitan Melbourne, we have one shot at avoiding Stage 4 lockdowns. Until mid-August:

  • Stay home, work from home if you can,
  • Wash hands regularly and thoroughly and use hand sanitiser,
  • Spend time outdoors if you have an outdoor area at home,
  • Care for older people by engaging with them virtually, rather than face to face, and
  • Wear a mask, as a reminder, a signal and an actual control measure.