As the cases begin to build up – but are still pretty low with limited community spread having been detected – now is a good time to start watching where and at what rate cases are in Australia. Below are a few quick graphs.
Images combined from CDC PHIL and Photo by Joey Csunyo on Unsplash
The situation at 71 cases
These data are harvested from the excellent public-facing and online National Notifiable Diseases Surveillance System – or NNDSS. I have been using them in recent years for influenza virus and more recently for measles virus last year.
My only criticisms of the NNDSS data (I’d have to have one wouldn’t I?) are that they are a bit late. For example, in Australia, we’re officially up to 80 (now 81!) cases today. Also, we can’t get daily data from the NNDSS site. I really wish we could so I could make nicer graphs. But such is life.
Confirmed COVID-19: what’s in a case?
As of the 05MAR2020, confirmation in Australia (see definition in eth image below) requires detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). As it should.
Case curves
In the graph below we can see the confirmed coronavirus disease 2019 (COVID-19) cases by month for Australia. I’ve added in eth latest numbers but I can’t add age or sex details until NNDSS updates those. so there will be a bit of disconnect in order to see the latest totals.
States (and territories) and rates
New South Wales has so far hosted most of Australia’s COVID-19 cases and is experiencing some community transmission not knowingly linked to travellers. So far case numbers are relatively low but even while preparing this blog today, cases went up a little.
Sex, age and SARS-CoV-2
So far cases may be a bit over-represented among older males, but they are mostly found among adults between 20 to 65 years of age in Australia. Case totals still include a lot of travellers at this stage.
Data here support what we have repeatedly seen from China; illnesses sufficient to put children on the radar for testing are uncommon. Whether children with mild illness are being missed and whether they could be a source of transmission remain unclear issues right now.
So here is the start of things. We have no exact idea what the speed of spread will be from here on out, but with community transmission picking up in News South Wales at least, here is a decent approximate starting pint.
An amateur asks: Given the Drosten study (nasal shedding) and some early-in-illness cases with high viral load on nasal swabs, isn’t it now even more important to find out if non-sick kids are little spreading machines? No evidence yet from close contacts of parents (etc) with COVID-19?
The testing mantra seems to be don’t test if no symptoms so I don’t think we yet have an idea about this. Which seems like research that needed to be done at the outset. But we keep playing catchup. Despite decades of virology and epidemiology to guide us.
Brendan Murphy has flat out said that if you have acute, flu like symptoms you are not a candidate for testing unless you have come from overseas or contacted a known case.
What exactly is it that makes you think any of the data is worth a damn?
I expect there’s a shortage of testing kits like everything else, and they are saving it for the severely ill to isolate the right people.
Having studied previous epidemics, can you speculate on what the spread could be throughout the community? This is what will define the total mortality. It is the only important question, yet no one is considering it. Clearly it will become endemic, but in that first season or two, what ballpark figures could we expect?
I don’t know why the journos don’t stick you on the news, there is a distinct lack of epidemiologists\virologists being asked these questions. Instead we have clown surgeon generals issuing motherhood statements, then acting confused when no one believes them and buys up all the bog roll in sight.
Finally – China has gone very quiet, no? Fearless leader has stopped the virus at the borders of Wuhan?
It’s broken out into a full scale pandemic, and if the real mortality rate is an order of magnitude below the one we’ve derived from the obviously ill, a 20% infected in the first season is a lot of deaths.
We need you on the news Dr Mackay.
Good points and questions.
If testing only those who are symptomatic and have recently been overseas and those known close contacts of confirmed cases, do we really have an accurate picture of community prevelence?
Probably not.
A lot of tests and been done on contacts of cases, Tens of thousands in NSW and Victoria, with very low detection rates. 1000 in Victoria got the zero cases.
These same individuals can be regarded as equivalent to community sampling.
Or if you prefer, why would random community individuals without contacts or risk factors be likely to have any greater incidence?
Is it possible or actually being done to collect specimens for storage and retrospective analysis?
I’m wondering if the virus wasn’t present in Australia in october november 2019.
I remember having all the symptomes along with lots of people around me.
I know for sure that it was different from the normal flu.
It lasted longer and I had a dry caugh.
My mother in law had a pneumonia.
It would be interesting to know if the doctors or hospitals records had more cases of pneumonia then normal at the end of last year.
There are many different viruses that can cause those symptoms.
I was in Australia in Nov 2019 (visiting from UK) I had a chest infection, continuous cough, and generally felt rough for 3 weeks. My usual colds never last this long and I rarely have chest infections. At the time I put it down to lots of air conditioning, flights, and change in climate, but I’m not so sure now.